Document:

EX-10.3

 Exhibit 10.3 

ALTIMMUNE, INC. 
 2018
INDUCEMENT GRANT PLAN 

 TABLE OF CONTENTS 

 

							
	 	 	 	  	Page	 
	 ARTICLE I PURPOSE
	  	 	1	 
		
	 ARTICLE II DEFINITIONS
	  	 	1	 
			
	 2.1
	 	“Acquisition Event”	  	 	1	 
	 2.2
	 	“Affiliate”	  	 	1	 
	 2.3
	 	“Appreciation Award”	  	 	1	 
	 2.4
	 	“Award”	  	 	1	 
	 2.5
	 	“Board”	  	 	2	 
	 2.6
	 	“Cause”	  	 	2	 
	 2.7
	 	“Change in Control”	  	 	2	 
	 2.8
	 	“Change in Control Price”	  	 	2	 
	 2.9
	 	“Code”	  	 	2	 
	 2.10
	 	“Committee”	  	 	2	 
	 2.11
	 	“Common Stock”	  	 	3	 
	 2.12
	 	“Company”	  	 	3	 
	 2.13
	 	“Competitor”	  	 	3	 
	 2.14
	 	“Consultant”	  	 	3	 
	 2.15
	 	“Detrimental Activity”	  	 	3	 
	 2.16
	 	“Disability”	  	 	4	 
	 2.17
	 	“Disparagement”	  	 	4	 
	 2.18
	 	“Effective Date”	  	 	4	 
	 2.19
	 	“Eligible Employee”	  	 	4	 
	 2.20
	 	“Employee”	  	 	4	 
	 2.21
	 	“Exchange Act”	  	 	5	 
	 2.22
	 	“Exercisable Awards”	  	 	5	 
	 2.23
	 	“Fair Market Value”	  	 	5	 
	 2.24
	 	“Family Member”	  	 	5	 
	 2.25
	 	“HMRC”	  	 	5	 
	 2.26
	 	“Incentive Stock Option”	  	 	5	 
	 2.27
	 	“Lead Underwriter”	  	 	5	 
	 2.28
	 	“Lock-Up Period”	  	 	5	 
	 2.29
	 	“Non-Employee Director”	  	 	5	 
	 2.30
	 	“Non-Qualified Stock Option”	  	 	5	 
	 2.31
	 	“Other Extraordinary Event”	  	 	5	 
	 2.32
	 	“Other Stock-Based Award”	  	 	5	 
	 2.33
	 	“Parent”	  	 	5	 
	 2.34
	 	“Participant”	  	 	5	 
	 2.35
	 	“Performance Share”	  	 	6	 
	 2.36
	 	“Performance Unit”	  	 	6	 
	 2.37
	 	“Person”	  	 	6	 
	 2.38
	 	“Plan”	  	 	6	 

  
 i 

							
	 2.39
	 	“Registration Date”	  	 	6	 
	 2.40
	 	“Restricted Stock”	  	 	6	 
	 2.41
	 	“Restriction Period”	  	 	6	 
	 2.42
	 	“Rule 16b-3”	  	 	6	 
	 2.43
	 	“Secondary Contributions”	  	 	6	 
	 2.44
	 	“Secondary Contributor”	  	 	6	 
	 2.45
	 	“Section 4.2 Event”	  	 	6	 
	 2.46
	 	“Section 409A Covered Award”	  	 	6	 
	 2.47
	 	“Section 409A”	  	 	6	 
	 2.48
	 	“Securities Act”	  	 	6	 
	 2.49
	 	“Stock Option” or “Option”	  	 	6	 
	 2.50
	 	“Subsidiary”	  	 	6	 
	 2.51
	 	“Termination”	  	 	7	 
	 2.52
	 	“Transfer”	  	 	7	 
		
	 ARTICLE III ADMINISTRATION
	  	 	7	 
			
	 3.1
	 	The Committee	  	 	7	 
	 3.2
	 	Grant and Administration of Awards	  	 	7	 
	 3.3
	 	Award Agreements	  	 	8	 
	 3.4
	 	Guidelines	  	 	8	 
	 3.5
	 	Delegation; Advisors	  	 	8	 
	 3.6
	 	Decisions Final	  	 	8	 
	 3.7
	 	Procedures	  	 	8	 
	 3.8
	 	Liability; Indemnification	  	 	9	 
		
	 ARTICLE IV SHARE LIMITATIONS
	  	 	9	 
			
	 4.1
	 	Shares	  	 	9	 
	 4.2
	 	Changes	  	 	10	 
	 4.3
	 	Minimum Purchase Price	  	 	11	 
		
	 ARTICLE V ELIGIBILITY
	  	 	11	 
		
	 ARTICLE VI STOCK OPTIONS
	  	 	11	 
			
	 6.1
	 	Stock Options	  	 	11	 
	 6.2
	 	Terms of Stock Options	  	 	11	 
		
	 ARTICLE VII RESTRICTED STOCK
	  	 	14	 
			
	 7.1
	 	Awards of Restricted Stock	  	 	14	 
	 7.2
	 	Awards and Certificates	  	 	14	 
	 7.3
	 	Restrictions and Conditions	  	 	15	 
		
	 ARTICLE VIII OTHER STOCK-BASED AWARDS
	  	 	16	 
			
	 8.1
	 	Other Awards	  	 	16	 
	 8.2
	 	Terms and Conditions	  	 	16	 

  
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	 ARTICLE IX CHANGE IN CONTROL PROVISIONS
	  	 	17	 
		
	 ARTICLE X TERMINATION OR AMENDMENT OF PLAN
	  	 	18	 
		
	 ARTICLE XI UNFUNDED PLAN
	  	 	18	 
		
	 ARTICLE XII GENERAL PROVISIONS
	  	 	18	 
			
	 12.1
	 	Legend	  	 	18	 
	 12.2
	 	Other Plans	  	 	19	 
	 12.3
	 	No Right to Employment/Consultancy/Directorship	  	 	19	 
	 12.4
	 	Withholding of Taxes	  	 	19	 
	 12.5
	 	No Assignment of Benefits	  	 	19	 
	 12.6
	 	Listing and Other Conditions	  	 	19	 
	 12.7
	 	Governing Law	  	 	20	 
	 12.8
	 	Construction	  	 	20	 
	 12.9
	 	No Acquired Rights	  	 	20	 
	 12.10
	 	Data Protection	  	 	21	 
	 12.11
	 	Costs	  	 	21	 
	 12.12
	 	No Right to Same Benefits	  	 	21	 
	 12.13
	 	Death/Disability	  	 	21	 
	 12.14
	 	Section 16(b) of the Exchange Act	  	 	21	 
	 12.15
	 	Section 409A	  	 	21	 
	 12.16
	 	Successor and Assigns	  	 	22	 
	 12.17
	 	Severability of Provisions	  	 	22	 
	 12.18
	 	Participants Subject to Taxation outside the U.S.; No Tax Equalization	  	 	22	 
	 12.19
	 	Payments to Minors, Etc.	  	 	23	 
	 12.20
	 	Headings and Captions	  	 	23	 
	 12.21
	 	Recoupment	  	 	23	 
	 12.22
	 	Reformation	  	 	23	 
	 12.23
	 	Electronic Communications	  	 	23	 
	 12.24
	 	Agreement	  	 	23	 
	 12.25
	 	Defense of Trade Secrets Act	  	 	24	 
		
	 ARTICLE XIII EFFECTIVE DATE OF PLAN; STOCKHOLDER APPROVAL NOT REQUIRED
	  	 	24	 
		
	 ARTICLE XIV TERM OF PLAN
	  	 	24	 
		
	 UK ADDENDUM
	  			
			
	 1.
	 	Purpose	  			
	 2.
	 	Definitions	  			
	 3.
	 	Terms	  			
	 4.
	 	Withholding Obligations	  			
	 5.
	 	Section 431 Elections	  			

  

  
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 ALTIMMUNE, INC. 

 
  

2018 INDUCEMENT GRANT PLAN 
  

 
 ARTICLE I

 PURPOSE 
 The purposes
of this Altimmune, Inc. 2018 Inducement Grant Plan are to (i) enhance the profitability and value of the Company for the benefit of its stockholders by enabling the Company to offer Eligible Employees incentive awards to attract, retain and
reward such individuals and strengthen the mutuality of interests between such Eligible Employees and the Company’s stockholders, and (ii) enable compliance with the inducement equity grant exception to stockholder approval of equity
issuances under Nasdaq Stock Market Listing Rule 5635(c)(4) by providing equity compensation issuances to any prospective employee who was not previously an employee or director of the Company, or following a bona fide period of non-employment, as an inducement material to the individual entering into employment with the Company. The Plan, as set forth herein, is effective as of the Effective Date (as defined in Article XIII). 

ARTICLE II 
 DEFINITIONS

 For purposes of the Plan, the following terms shall have the following meanings: 

2.1 “Acquisition Event” means a merger or consolidation in which the Company is not the surviving entity, any
transaction that results in the acquisition of all or substantially all of the Company’s outstanding Common Stock by a single person or entity or by a group of persons or entities acting in concert, or the sale or transfer of all or
substantially all of the Company’s assets. 
 2.2 “Affiliate” means each of the following: (a) any
Subsidiary; (b) any Parent; (c) any corporation, trade or business (including a partnership or limited liability company) that is directly or indirectly controlled 50% or more (whether by ownership of stock, assets or an equivalent
ownership interest or voting interest) by the Company or any Affiliate; (d) any corporation, trade or business (including a partnership or limited liability company) that directly or indirectly controls 50% or more (whether by ownership of
stock, assets or an equivalent ownership interest or voting interest) of the Company; and (e) any other entity in which the Company or any Affiliate has a material equity interest and that is designated as an “Affiliate” by resolution
of the Committee. 
 2.3 “Appreciation Award” means any Stock Option or any Other Stock-Based Award that is
based on the appreciation in value of a share of Common Stock in excess of an amount at least equal to the Fair Market Value on the date such Stock Option or Other Stock-Based Award is granted. 

2.4 “Award” means any award granted or made under the Plan of any Stock Option, Restricted Stock or Other Stock-Based
Award. 

  
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 2.5 “Board” means the Board of Directors of the Company. 

2.6 “Cause” means, with respect to a Participant’s Termination of Employment or Termination of Consultancy: unless
otherwise defined in the applicable Award agreement or other written agreement approved by the Committee, a termination due to (i) the Participant’s conviction of, or plea of guilty or nolo contendere to, a felony;
(ii) perpetration by the Participant of an illegal act, dishonesty or fraud that could have a significant adverse effect on the Company or its assets or reputation; or (iii) the Participant’s willful misconduct with regard to the
Company, as determined by the Committee. 
 2.7 “Change in Control” unless otherwise defined in the applicable
Award agreement or other written agreement approved by the Committee and subject to Section 12.14(b), means the occurrence of any of the following: 

(a) the acquisition (including through purchase, reorganization, merger, consolidation or similar transaction), directly or indirectly, in one
or more transactions by a Person of beneficial ownership (within the meaning of Rule 13d-3 under the Exchange Act) of securities representing 50% or more of the combined voting power of the securities of the
Company entitled to vote generally in the election of directors of the Board, calculated on a fully diluted basis after giving effect to such acquisition; 

(b) an election of Persons to the Board that causes two-thirds of the Board to consist of Persons other
than (i) members of the Board on the Effective Date and (ii) Persons who were nominated for election as members of the Board at a time when two-thirds of the Board consisted of Persons who were
members of the Board on the Effective Date; provided that any Person nominated for election by a Board at least two-thirds of which consisted of Persons described in clauses (i) or (ii) or by
Persons who were themselves nominated by such Board shall be deemed to have been nominated by a Board consisting of Persons described in clause (i); or 

(c) the sale or other disposition, directly or indirectly, of all or substantially all of the assets of the Company and its subsidiaries, taken
as a whole, to any Person; 
 provided, however, that a Change in Control shall be deemed to not have occurred if such Change
in Control results from the issuance, in connection with a bona fide transaction or series of transactions with the primary purpose of providing equity financing to the Company or any of its Affiliates, of voting securities of the Company or any of
its Affiliates or any rights to acquire voting securities of the Company or any of its Affiliates which are convertible into voting securities. 

2.8 “Change in Control Price” has the meaning set forth in Section 9.1. 

2.9 “Code” means the Internal Revenue Code of 1986, as amended. Any reference to a section of the Code shall also be a
reference to any successor provision and any Treasury Regulation promulgated thereunder. 
 2.10 “Committee”
means the Compensation Committee of the Board or such other committee or subcommittee that is appointed by the Board, in each case, consisting of two or more non-employee directors, each of whom is
intended to be (a) to the extent required by Rule 16b-3, a “nonemployee director” as defined in Rule 16b-3; and (b) as applicable, an
“independent director” as defined under the Nasdaq Listing Rules, the NYSE Listed Company Manual or other applicable stock exchange rules. It is intended that, absent an affirmative decision by the Board to appoint a separate Committee,
the Compensation Committee of the Board shall serve as the 

  
 2 

 
“Committee”. To the extent that no Committee exists that has the authority to administer the Plan, the functions of the Committee shall be exercised by the Board and all references
herein to the Committee shall be deemed references to the Board. If for any reason the appointed Committee does not meet the requirements of Rule 16b-3, such noncompliance shall not affect the validity of
Awards, grants, interpretations or other actions of the Committee. 
 2.11 “Common Stock” means the common stock of
the Company, par value $0.001 per share. 
 2.12 “Company” means Altimmune, Inc., a Delaware corporation, and
its successors by operation of law. 
 2.13 “Competitor” means any Person that is, directly or indirectly, in
competition with the business or activities of the Company and its Affiliates. 
 2.14 “Consultant” means any
natural person who provides bona fide consulting or advisory services to the Company or its Affiliates, provided that such services are not in connection with the offer or sale of securities in a capital-raising transaction, and do not,
directly or indirectly, promote or maintain a market for the Company’s or its Affiliates’ securities. 
 2.15
“Detrimental Activity” means, unless otherwise defined in the applicable Award agreement or other written agreement approved by the Committee: 

(a) without written authorization from the Company, disclosure to any Person outside the Company and its Affiliates or the use in any manner,
except as necessary in the furtherance of Participant’s responsibilities to the Company or any of its Affiliates, at any time, of any confidential information, trade secrets or proprietary information relating to the business of the Company or
any of its Affiliates that is acquired by the Participant at any time prior to the Participant’s Termination; 
 (b) any activity while
employed or performing services that results, or if known could have reasonably been expected to result, in the Participant’s Termination for Cause; 

(c) without written authorization from the Company, directly or indirectly, in any capacity whatsoever, (i) own, manage, operate, control,
be employed by (whether as an employee, consultant, independent contractor or otherwise, and whether or not for compensation) or render services to any Competitor; (ii) solicit, aid or induce any customer of the Company or any Subsidiary to
curtail, reduce or terminate its business relationship with the Company or any Subsidiary, or in any other way interfere with any such business relationships with the Company or any Subsidiary; (iii) solicit, aid or induce any employee,
representative or agent of the Company or any Subsidiary to leave such employment or retention or to accept employment with or render services to or with any other person, firm, corporation or other entity unaffiliated with the Company or hire or
retain any such employee, representative or agent or take any action to materially assist or aid any other person, firm, corporation or other entity in identifying, hiring or soliciting any such employee, representative or agent; or
(iv) interfere, or aid or induce any other person or entity in interfering, with the relationship between the Company, its Subsidiaries and any of their respective vendors, joint venturers or licensors; 

(d) a material breach of any restrictive covenant contained in any agreement between the Participant and the Company or an Affiliate; or 

  
 3 

 (e) the Participant’s Disparagement, or inducement of other to do so, of the Company or
its Affiliates or their past or present officers, directors, employees or products. 
 Only the Chief Executive Officer or the Chief Financial Officer of
the Company (or his designee, as evidenced in writing) shall have the authority to provide the Participant, except for himself or herself, with written authorization to engage in the activities contemplated in subsections (a) and (c). 

2.16 “Disability” means, unless otherwise defined in the applicable Award agreement or other written agreement approved
by the Committee, with respect to a Participant’s Termination, a permanent and total disability as defined in Section 22(e)(3) of the Code. A Disability shall only be deemed to occur at the time of the determination by the Committee of the
Disability. Notwithstanding the foregoing, for an Award that provides for payment or settlement triggered upon a Disability and that constitutes a Section 409A Covered Award, the foregoing definition shall apply for purposes of vesting of such
Award, provided that for purposes of payment or settlement of such Award, such Award shall not be paid (or otherwise settled) until the earliest of: (A) the Participant’s “disability” within the meaning of
Section 409A(a)(2)(C)(i) or (ii) of the Code, (B) the Participant’s “separation from service” within the meaning of Section 409A and (C) the date such Award would otherwise be settled pursuant to the terms of
the Award agreement. 
 2.17 “Disparagement” means making comments or statements to the press, the
Company’s or its Affiliates’ employees, consultants or any individual or entity with whom the Company or its Affiliates has a business relationship which could reasonably be expected to adversely affect in any manner: (a) the conduct
of the business of the Company or its Affiliates (including any products or business plans or prospects); or (b) the business reputation of the Company or its Affiliates, or any of their products, or their past or present officers, directors or
employees. 
 2.18 “Effective Date” means the effective date of the Plan as defined in Article XIII.

 2.19 “Eligible Employee” means any Employee who has not previously been an Employee or a Non-Employee Director of the Company or a Subsidiary, or is commencing employment with the Company or a Subsidiary following a bona fide period of non-employment by the
Company or a Subsidiary, if he is granted an Award in connection with his commencement of employment with the Company or a Subsidiary and such grant is an inducement material to his entering into employment with the Company or a Subsidiary. The
Committee may in its discretion adopt procedures from time to time to ensure that an Employee is eligible to participate in the Plan prior to the granting of any Awards to such Employee under the Plan, including a requirement that each such Employee
certify to the Company prior to the receipt of an Award under the Plan that he has not been previously employed by the Company or a Subsidiary, or if previously employed, has had a bona fide period of
non-employment, and that the grant of Awards under the Plan is an inducement material to his agreement to enter into employment with the Company or a Subsidiary. 

2.20 “Employee” 

means any Person employed by the Company or any Subsidiary of the Company. Neither service as a
Non-Employee Director nor payment of a director’s fee by the Company will be sufficient to constitute “employment” by the Company. 

  
 4 

 2.21 “Exchange Act” means the Securities Exchange Act of 1934, as
amended, and all rules and regulations promulgated thereunder. Any references to any section of the Exchange Act shall also be a reference to any successor provision. 

2.22 “Exercisable Awards” has the meaning set forth in Section 4.2(d). 

2.23 “Fair Market Value” unless otherwise required by any applicable provision of the Code, means as of any date and
except as provided below, (a) the closing price reported for the Common Stock on such date: (i) as reported on the principal national securities exchange in the United States on which it is then traded; or (ii) if not traded on any
such national securities exchange, as quoted on an automated quotation system sponsored by the Financial Industry Regulatory Authority or (b) if the Common Stock shall not have been reported or quoted on such date, on the first day prior
thereto on which the Common Stock was reported or quoted. If the Common Stock is not traded, listed or otherwise reported or quoted, then Fair Market Value means the fair market value of the Common Stock as determined by the Committee in good faith
in whatever manner it considers appropriate taking into account the requirements of Section 409A or Section 422 of the Code, as applicable. Notwithstanding anything herein to the contrary, for purposes of any Stock Options that are granted
effective on the Registration Date, the Fair Market Value shall equal the initial public offering price of the Common Stock. 

2.24 “Family Member” means “family member” as defined in Section A.1.(5) of the general instructions of Form S-8, as may be amended from time to time. 
 2.25 “Incentive Stock Option”
means any Stock Option intended to be an “Incentive Stock Option” within the meaning of Section 422 of the Code. 

2.26 “Lead Underwriter” has the meaning in Section 12.24. 

2.27 “Lock-Up Period” has the meaning in Section 12.24. 

2.28 “Non-Employee Director” means a director of the Company or an Affiliate
who is not an active Employee of the Company or an Affiliate. 
 2.29
“Non-Qualified Stock Option” means any Stock Option that is not an Incentive Stock Option. 

2.30 “Other Extraordinary Event” has the meaning in Section 4.2(b). 

2.31 “Other Stock-Based Award” means an Award under Article VIII that is valued in whole or in part by reference to, or
is payable in or otherwise based on, Common Stock. 
 2.32 “Parent” means any parent corporation of the
Company within the meaning of Section 424(e) of the Code. 
 2.33 “Participant” means an Eligible
Employee to whom an Award has been granted pursuant to the Plan. 
 2.34 “Performance Share” means an Other
Stock-Based Award of the right to receive a number of shares of Common Stock or cash of an equivalent value at the end of a specified performance period. 

  
 5 

 2.35 “Performance Unit” means an Other Stock-Based Award of the
right to receive a fixed dollar amount, payable in cash or Common Stock or a combination of both, at the end of a specified performance period. 

2.36 “Person” means any individual, entity (including any employee benefit plan or any trust for an employee benefit
plan) or group (within the meaning of Section 13(d)(3) or Section 14(d)(2) of the Exchange Act, or any successor provision). 

2.37 “Plan” means this Altimmune, Inc. 2018 Inducement Grant Plan, as amended from time to time. 

2.38 “Registration Date” means the first date on or after the Effective Date (a) on which the Company sells its
Common Stock in a bona fide, firm commitment underwriting pursuant to a registration statement under the Securities Act or (b) any class of common equity securities of the Company is required to be registered under Section 12 of the
Exchange Act. 
 2.39 “Restricted Stock” means an Award of shares of Common Stock that is subject to
restrictions pursuant to Article VII. 
 2.40 “Restriction Period” has the meaning set forth in
Section 7.3(a). 
 2.41 “Rule 16b-3” means Rule 16b-3 under Section 16(b) of the Exchange Act as then in effect or any successor provision. 

2.42 “Secondary Contributions” has the meaning in Section 12.4(b). 

2.43 “Secondary Contributor” has the meaning in Section 12.4(b). 

2.44 “Section 4.2 Event” has the meaning set forth in Section 4.2(b). 

2.45 “Section 409A Covered Award” has the meaning set forth in Section 12.15. 

2.46 “Section 409A” means the nonqualified deferred compensation rules under Section 409A of
the Code. 
 2.47 “Securities Act” means the Securities Act of 1933, as amended and all rules and regulations
promulgated thereunder. Any reference to any section of the Securities Act shall also be a reference to any successor provision. 

2.48 “Stock Option” or “Option” means any option to purchase shares of Common Stock granted to
Eligible Employees pursuant to Article VI. 
 2.49 “Subsidiary” means any subsidiary corporation of the
Company within the meaning of Section 424(f) of the Code. 
 2.50 “Termination” means: (a) a
termination of employment (for reasons other than a military or approved personal leave of absence) of a Participant from the Company and its Affiliates; or (b) when an entity that is employing a Participant ceases to be an Affiliate, unless
the Participant otherwise is, or thereupon becomes, employed by the Company or another Affiliate at the time the entity ceases to be an Affiliate. In the event that an Eligible Employee becomes a Consultant or a
Non-Employee Director upon the termination of his employment, unless otherwise determined by the Committee, no Termination shall be deemed to occur until such time as such Eligible Employee is no longer an
Eligible Employee, a Consultant or a Non-Employee Director. Notwithstanding the foregoing, the Committee may otherwise define Termination in the Award agreement or, if no rights of a Participant are reduced,
may otherwise define Termination thereafter. 

  
 6 

 2.51 “Transfer” means: (a) when used as a noun, any direct or
indirect transfer, sale, assignment, pledge, hypothecation, encumbrance or other disposition (including the issuance of equity in a Person), whether for value or no value and whether voluntary or involuntary (including by operation of law), and
(b) when used as a verb, to directly or indirectly transfer, sell, assign, pledge, encumber, charge, hypothecate or otherwise dispose of (including the issuance of equity in a Person) whether for value or for no value and whether voluntarily or
involuntarily (including by operation of law). “Transferred” and “Transferable” shall have a correlative meaning. 

ARTICLE III 

ADMINISTRATION 
 3.1 The
Committee. The Plan shall be administered and interpreted by the Committee. 
 3.2 Grant and Administration of
Awards. The Committee shall have full authority and discretion, as provided in Section 3.6, to grant and administer Awards including the authority to: 

(a) adopt procedures from time to time in the Committee’s discretion to ensure that an Employee is eligible to participate in the Plan
prior to the grant of any Awards to such Employee under the Plan, including a requirement, if any, that each such Employee certify to the Company prior to the receipt of an Award under the Plan that he has not been previously employed by the Company
or a Subsidiary, or if previously employed, has had a bona fide period of non-employment, and that the grant of Awards under the Plan is an inducement material to his agreement to enter into employment
with the Company or a Subsidiary; 
 (b) select the Eligible Employees to whom Awards may from time to time be granted; 

(c) determine the number of shares of Common Stock to be covered by each Award; 

(d) determine the type and the terms and conditions, not inconsistent with the terms of the Plan, of each Award (including the exercise or
purchase price (if any), any restriction or limitation or any vesting schedule or acceleration thereof); 
 (e) determine whether to require
a Participant, as a condition of the granting of any Award, to refrain from selling or otherwise disposing of Common Stock acquired pursuant to such Award for a period of time as determined by the Committee; 

(f) condition the grant, vesting or payment of any Award on the attainment of performance goals over a performance period specified by the
Committee, set such goals and such period, and certify the attainment of such goals; 
 (g) amend, after the date of grant, the terms that
apply to an Award upon a Participant’s Termination, provided that such amendment does not reduce the Participant’s rights under the Award; 

  
 7 

 (h) determine the circumstances under which Common Stock and other amounts payable with
respect to an Award may be deferred automatically or at the election of the Participant, in each case in a manner intended to comply with or be exempt from Section 409A; 

(i) generally, exercise such powers and perform such acts as the Committee deems necessary or advisable to promote the best interests of the
Company in connection with the Plan that are not inconsistent with the provisions of the Plan; 
 (j) construe and interpret the terms and
provisions of the Plan and any Award (and any agreements relating thereto); and 
 (k) correct any defect, supply any omission or reconcile
any inconsistency in the Plan or in any agreement relating thereto. 
 3.3 Award Agreements. All Awards shall be evidenced by,
and subject to the terms and conditions of, a written notice provided by the Company to the Participant or a written agreement executed by the Company and the Participant. 

3.4 Guidelines. The Committee shall have the authority to adopt, alter and repeal such administrative rules, guidelines and
practices governing the Plan as it shall, from time to time, deem necessary or advisable. The Committee may adopt special guidelines and provisions for Persons who are residing in or employed in, or subject to, the taxes of, any domestic or foreign
jurisdiction to comply with applicable tax and securities laws and may impose such limitations and restrictions that it deems necessary or advisable to comply with the applicable tax and securities laws of such domestic or foreign jurisdiction.

 3.5 Delegation; Advisors. The Committee may, as it from time to time as it deems advisable, to the extent permitted by
applicable law and stock exchange rules: 
 (a) delegate authority to officers or Employees of the Company and its Affiliates to
execute agreements or other documents on behalf of the Committee; and 
 (b) engage legal counsel, consultants, professional advisors and
agents to assist in the administration of the Plan and rely upon any opinion or computation received from any such Person. Expenses incurred by the Committee or the Board in the engagement of any such person shall be paid by the Company. 

3.6 Decisions Final. All determinations, evaluations, elections, approvals, authorizations, consents, decisions, interpretations
and other actions made or taken by or at the direction of the Company, the Board or the Committee (or any of its members) arising out of or in connection with the Plan shall be within the sole and absolute discretion of all and each of them, and
shall be final, binding and conclusive on all employees and Participants and their respective beneficiaries, heirs, executors, administrators, successors and assigns. 

3.7 Procedures. If the Committee is appointed, the Board shall designate one of the members of the Committee as chairman and the
Committee shall hold meetings, subject to the By-Laws of the Company, at such times and places as it shall deem advisable, including by telephone conference or by written consent to the extent permitted by
applicable law. A majority of the Committee members shall constitute a quorum. All determinations of the Committee shall be made by a majority of its members. Any decision or determination reduced to writing and signed by all of the Committee
members in accordance with the By-Laws of the Company, shall be fully effective as if it had been made by a vote at a meeting duly called and held. The Committee shall keep minutes of its meetings and shall
make such rules and regulations for the conduct of its business as it shall deem advisable. 

  
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 3.8 Liability; Indemnification. 

(a) The Committee, its members and any delegate or Person engaged pursuant to Section 3.5 shall not be liable for any action or
determination made in good faith with respect to the Plan. To the maximum extent permitted by applicable law, no officer or Employee of the Company or any Affiliate or member or former member of the Committee or of the Board shall be liable for any
action or determination made in good faith with respect to the Plan or any Award granted under it. 
 (b) To the maximum extent permitted by
applicable law and the Certificate of Incorporation and By-Laws of the Company and to the extent not covered by insurance directly insuring such person, each current or former officer or Employee of the
Company or any Affiliate and member of the Committee or the Board shall be indemnified and held harmless by the Company against any cost or expense (including reasonable fees of counsel reasonably acceptable to the Committee) or liability (including
any sum paid in settlement of a claim with the approval of the Committee), and advanced amounts necessary to pay the foregoing at the earliest time and to the fullest extent permitted, arising out of any act or omission to act in connection with the
administration of the Plan, except to the extent arising out of such Person’s own fraud or bad faith. Such indemnification shall be in addition to any rights of indemnification provided for under applicable law or under the Certificate of
Incorporation or By-Laws of the Company or any Affiliate. Notwithstanding anything else herein, this indemnification will not apply to the actions or determinations made by an individual with regard to Awards
granted to him. 
 ARTICLE IV 

SHARE LIMITATIONS 
 4.1
Shares. 
 (a) Subject to Section 4.2, the aggregate number of shares of Common Stock which may be issued or used for
reference purposes or with respect to which Awards under the Plan may be granted over the term of the Plan is 2,000,000. At all times, the Company will reserve and keep available a sufficient number of Common Stock as will be required to satisfy the
requirements of all Awards granted and outstanding under the Plan. 
 (b) If any Appreciation Award expires, terminates or is canceled for
any reason without having been exercised in full, the number of shares of Common Stock underlying any unexercised portion shall again be available under the Plan. If shares of Restricted Stock or Other Stock-Based Awards that are not Appreciation
Awards are forfeited for any reason, the number of forfeited shares comprising or underlying the Award shall again be available under the Plan. 

(c) Shares of Common Stock that are not issued pursuant to net settlement or which are used to pay any exercise price or tax withholding
obligation with respect to any Award shall not be available under the Plan. Notwithstanding anything to the contrary herein, Awards that may be settled solely in cash shall not be deemed to use any shares under the Plan. 

(d) Shares issued under the Plan may be either authorized and unissued Common Stock or Common Stock held in or acquired for the treasury of the
Company, or both. 

  
 9 

 4.2 Changes. 

(a) The existence of the Plan and the Awards shall not affect in any way the right or power of the Board or the stockholders of the Company to
make or authorize (i) any adjustment, recapitalization, reorganization or other change in the Company’s capital structure or its business, (ii) any merger or consolidation of the Company or any Affiliate, (iii) any issuance of
bonds, debentures, preferred or prior preference stock ahead of or affecting the Common Stock, (iv) the dissolution or liquidation of the Company or any Affiliate, (v) any sale or transfer of all or part of the assets or business of the
Company or any Affiliate, (vi) any Section 4.2 Event or (vii) any other corporate act or proceeding. 
 (b) Subject to the
provisions of Section 4.2(d), in the event of any change in the capital structure or business of the Company by reason of any stock split, reverse stock split, stock dividend, combination or reclassification of shares, recapitalization, merger,
consolidation, spin off, split off, reorganization or partial or complete liquidation, issuance of rights or warrants to purchase Common Stock or securities convertible into Common Stock, sale or transfer of all or part of the Company’s assets
or business, or other corporate transaction or event that would be considered an “equity restructuring” within the meaning of FASB ASC Topic 718 (each, a “Section 4.2 Event”), then
(i) the aggregate number or kind of shares that thereafter may be issued under the Plan, (ii) the number or kind of shares or other property (including cash) subject to an Award, or (iii) the purchase or exercise price of Awards shall
be adjusted by the Committee as the Committee determines, in good faith, to be necessary or advisable to prevent substantial dilution or enlargement of the rights of Participants under the Plan. In connection with any Section 4.2 Event, the
Committee may provide for the cancellation of outstanding Awards and payment in cash or other property in exchange therefor. In addition, subject to Section 4.2(d), in the event of any change in the capital structure of the Company that is not
a Section 4.2 Event (an “Other Extraordinary Event”), then the Committee may make the adjustments described in clauses (i) through (iii) above as it determines, in good faith, to be necessary or advisable to prevent
substantial dilution or enlargement of the rights of Participants under the Plan. Notice of any such adjustment shall be given by the Committee to each Participant whose Award has been adjusted and such adjustment (whether or not such notice is
given) shall be binding for all purposes of the Plan. Except as expressly provided in this Section 4.2(b) or in the applicable Award agreement, a Participant shall have no rights by reason of any Section 4.2 Event or any Other
Extraordinary Event. Notwithstanding the foregoing, (x) any adjustments made pursuant to Section 4.2(b) to Awards that are considered “non-qualified deferred compensation” within the
meaning of Section 409A shall be made in a manner intended to comply with the requirements of Section 409A; and (y) any adjustments made pursuant to Section 4.2(b) to Awards that are not considered
“non-qualified deferred compensation” subject to Section 409A shall be made in a manner intended to ensure that after such adjustment, the Awards either (A) continue to be exempt from
Section 409A or (B) comply with the requirements of Section 409A. 
 (c) Fractional shares of Common Stock resulting from any
adjustment in Awards pursuant to Section 4.2(a) or (b) shall be aggregated until, and eliminated at, the time of exercise by rounding-down for fractions less than one-half and rounding-up for fractions equal to or greater than one-half. No cash settlements shall be made with respect to fractional shares eliminated by rounding. 

  
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 (d) Upon the occurrence of an Acquisition Event, the Committee may terminate all outstanding
and unexercised Stock Options or any Other Stock-Based Award that provides for a Participant-elected exercise (collectively, “Exercisable Awards”), effective as of the date of the Acquisition Event, by delivering notice of
termination to each Participant at least 20 days prior to the date of consummation of the Acquisition Event, in which case during the period from the date on which such notice of termination is delivered to the consummation of the Acquisition Event,
each such Participant shall have the right to exercise in full all of such Exercisable Awards that are then outstanding to the extent vested on the date such notice of termination is given (or, at the discretion of the Committee, without regard to
any limitations on exercisability otherwise contained in the Award agreements), but any such exercise shall be contingent on the occurrence of the Acquisition Event, and, provided that, if the Acquisition Event does not take place within a
specified period after giving such notice for any reason whatsoever, the notice and exercise pursuant thereto shall be null and void and the applicable provisions of Section 4.2(b) and Article IX shall apply. For the avoidance of doubt, in the
event of an Acquisition Event, the Committee may terminate any Exercisable Award for which the exercise price is equal to or exceeds the Fair Market Value on the date of the Acquisition Event without payment of consideration therefor. If an
Acquisition Event occurs but the Committee does not terminate the outstanding Awards pursuant to this Section 4.2(d), then the provisions of Section 4.2(b) and Article IX shall apply. 

4.3 Minimum Purchase Price. Notwithstanding any provision of the Plan to the contrary, if authorized but previously unissued
shares of Common Stock are issued under the Plan, such shares shall not be issued for a consideration that is less than permitted under applicable law. 

ARTICLE V 
 ELIGIBILITY

 All Eligible Employees are eligible to be granted Awards. Eligibility for the grant of Awards and actual participation in the Plan shall
be determined by the Committee in its sole discretion. The grant of Awards to a prospective Eligible Employee and the vesting and exercise of such Awards shall be conditioned upon such Person actually becoming an Eligible Employee, and shall, in
each case, be subject to any requirements of applicable laws, including the securities laws of all relevant jurisdictions. Notwithstanding anything herein to the contrary, no Award under which a Participant may receive shares of Common Stock may be
granted to an Eligible Employee if such shares of Common Stock do not constitute “service recipient stock” for purposes of Section 409A with respect to such Eligible Employee if such shares are required to constitute “service
recipient stock” for such Award to comply with, or be exempt from, Section 409A. 
 ARTICLE VI 

STOCK OPTIONS 
 6.1 Stock
Options. Each Stock Option granted hereunder shall constitute a Non-Qualified Stock Option. Incentive Stock Options may not be granted under the Plan. 

6.2 Terms of Stock Options. Stock Options granted under the Plan shall be subject to the following terms and conditions and shall
be in such form and contain such additional terms and conditions, not inconsistent with the terms of the Plan, as the Committee shall deem desirable: 

(a) Exercise Price. The exercise price per share of Common Stock subject to a Stock Option shall be determined by the Committee on or
before the date of grant, provided that the per share exercise price of a Stock Option shall not be less than 100% of the Fair Market Value of the Common Stock on the date of grant. 

  
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 (b) Stock Option Term. The term of each Stock Option shall be fixed by the Committee,
provided that no Stock Option shall be exercisable more than ten years after the date such Stock Option is granted. 
 (c)
Exercisability. 
 (i) Stock Options shall be exercisable at such time or times and subject to such terms and conditions as shall be
determined by the Committee in the applicable Award agreement. The Committee may waive any limitations on exercisability at any time at or after grant in whole or in part, in its discretion. 

(ii) Unless otherwise determined by the Committee in the applicable Award agreement, (A) in the event the Participant engages in
Detrimental Activity prior to any exercise of the Stock Option, all Stock Options held by the Participant shall thereupon terminate and expire, (B) as a condition of the exercise of a Stock Option, the Participant shall be required to certify
in a manner acceptable to the Company (or shall be deemed to have certified) that the Participant is in compliance with the terms and conditions of the Plan and that the Participant has not engaged in, and does not intend to engage in, any
Detrimental Activity, and (C) in the event the Participant engages in Detrimental Activity during the one-year period commencing on the earlier of the date the Stock Option is exercised or the date of the
Participant’s Termination, the Company shall be entitled to recover from the Participant at any time within one year after such date, and the Participant shall pay over to the Company, an amount equal to any gain realized (whether at the time
of exercise or thereafter) as a result of the exercise. Unless otherwise determined by the Committee in the applicable Award agreement, this Section 6.2(c)(ii) shall cease to apply upon a Change in Control. 

(d) Method of Exercise. To the extent vested, a Stock Option may be exercised in whole or in part at any time during the Option term, by
giving written notice of exercise to the Committee (or its designee) specifying the number of shares of Common Stock to be purchased. Such notice shall be in a form acceptable to the Committee and shall be accompanied by payment in full of the
purchase price as follows: (i) in cash or by check, bank draft or money order payable to the order of the Company; (ii) solely to the extent permitted by applicable law and authorized by the Committee, if the Common Stock is traded on a
national securities exchange or quoted on a national quotation system sponsored by the Financial Industry Regulatory Authority, through a procedure whereby the Participant delivers irrevocable instructions to a broker reasonably acceptable to the
Committee to deliver promptly to the Company an amount equal to the purchase price; or (iii) on such other terms and conditions as may be acceptable to the Committee (including the relinquishment of Stock Options or by payment in full or in
part in the form of Common Stock owned by the Participant (for which the Participant has good title free and clear of any liens and encumbrances)). No shares of Common Stock shall be issued until payment therefor, as provided herein, has been made
or provided for. 
 (e) Non-Transferability of Options. No Stock Option shall be Transferable
by the Participant other than by will or by the laws of descent and distribution, and all Stock Options shall be exercisable, during the Participant’s lifetime, only by the Participant. Notwithstanding the foregoing, the Committee may determine
that a Stock Option that otherwise is not Transferable pursuant to this section is Transferable to a Family Member in whole or in part, and in such 

  
 12 

 
circumstances, and under such conditions as specified by the Committee. A Stock Option that is Transferred to a Family Member pursuant to the preceding sentence (i) may not be Transferred
subsequently other than by will or by the laws of descent and distribution and (ii) remains subject to the terms of the Plan and the applicable Award agreement. Any shares of Common Stock acquired upon the exercise of a Stock Option by a
permissible transferee of a Stock Option or a permissible transferee pursuant to a Transfer after the exercise of the Stock Option shall be subject to the terms of this Plan and the applicable Award agreement. 

(f) Termination by Death or Disability. Unless otherwise determined by the Committee at grant (or, if no rights of the Participant (or,
in the case of his death, his estate) are reduced, thereafter), if a Participant’s Termination is by reason of death or Disability, all Stock Options that are held by such Participant that are vested and exercisable on the date of the
Participant’s Termination may be exercised by the Participant (or, in the case of death, by the legal representative of the Participant’s estate) at any time within a period of one year after the date of such Termination, but in no event
beyond the expiration of the stated term of such Stock Options. 
 (g) Involuntary Termination without Cause. Unless otherwise
determined by the Committee at grant (or, if no rights of the Participant (or, in the case of his death, his estate) are reduced, thereafter), if a Participant’s Termination is by involuntary termination by the Company or an Affiliate without
Cause, all Stock Options that are held by such Participant that are vested and exercisable on the date of the Participant’s Termination may be exercised by the Participant at any time within a period of 90 days after the date of such
Termination, but in no event beyond the expiration of the stated term of such Stock Options. 
 (h) Voluntary Termination. Unless
otherwise determined by the Committee at grant (or, if no rights of the Participant (or, in the case of his death, his estate) are reduced, thereafter), if a Participant’s Termination is voluntary (other than a voluntary Termination described
in subsection (i)(B) below), all Stock Options that are held by such Participant that are vested and exercisable on the date of the Participant’s Termination may be exercised by the Participant at any time within a period of 30 days after the
date of such Termination, but in no event beyond the expiration of the stated term of such Stock Options. 
 (i) Termination for
Cause. Unless otherwise determined by the Committee at grant (or, if no rights of the Participant (or, in the case of his death, his estate) are reduced, thereafter), if a Participant’s Termination (A) is for Cause or (B) is a
voluntary Termination after the occurrence of an event that would be grounds for a Termination for Cause, all Stock Options, whether vested or not vested, that are held by such Participant shall terminate and expire on the date of such Termination.

 (j) Unvested Stock Options. Unless otherwise determined by the Committee, Stock Options that are not vested as of the date of a
Participant’s Termination for any reason shall terminate and expire on the date of such Termination. 
 (k) Form, Modification,
Extension and Renewal of Stock Options. Stock Options may be evidenced by such form of agreement as is approved by the Committee. The Committee may (i) modify, extend or renew outstanding Stock Options (provided that (A) the
rights of a Participant are not reduced without his consent and (B) such action does not subject the Stock Options to Section 409A or otherwise extend the Stock Options beyond their stated term), and (ii) accept the surrender of
outstanding Stock Options and authorize the granting of new Stock Options in substitution therefor. Notwithstanding anything herein to the contrary, an outstanding Option may not be modified to reduce the exercise price thereof nor may a new Option
at a lower exercise price be substituted for a surrendered Option (other than adjustments or substitutions in accordance with Section 4.2), unless such action is approved by the stockholders of the Company. 

  
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 (l) No Reload Options. Options shall not provide for the grant of the same number of
Options as the number of shares used to pay for the exercise price of Options or shares used to pay withholding taxes (i.e., “reloads”). 

ARTICLE VII 
 RESTRICTED
STOCK 
 7.1 Awards of Restricted Stock. The Committee shall determine the Participants to whom, and the time or times at
which, grants of Restricted Stock shall be made, the number of shares to be awarded, the purchase price (if any) to be paid by the Participant (subject to Section 7.2), the time or times at which such Awards may be subject to forfeiture or to
restrictions on transfer, and all other terms and conditions of the Awards. 
 Unless otherwise determined by the Committee in the
applicable Award agreement, (A) in the event the Participant engages in Detrimental Activity prior to any vesting of Restricted Stock, all unvested Restricted Stock shall be immediately forfeited, and (B) in the event the Participant
engages in Detrimental Activity during the one year period after any vesting of such Restricted Stock, the Committee shall be entitled to recover from the Participant (at any time within one year after such engagement in Detrimental Activity) an
amount equal to the Fair Market Value as of the vesting date(s) of any Restricted Stock that had vested in the period referred to above. Unless otherwise determined by the Committee in the applicable Award agreement, this paragraph shall cease to
apply upon a Change in Control. 
 The Committee may condition the grant or vesting of Restricted Stock upon the attainment of specified
performance goals or such other factors as the Committee may determine. 
 7.2 Awards and Certificates. The Committee may
require, as a condition to the effectiveness of an Award of Restricted Stock, that the Participant execute and deliver to the Company an Award agreement or other documentation and comply with the terms of such Award agreement or other documentation.
Further, Restricted Stock shall be subject to the following conditions: 
 (a) Purchase Price. The purchase price of Restricted Stock,
if any, shall be fixed by the Committee. In accordance with Section 4.3, the purchase price for shares of Restricted Stock may be zero to the extent permitted by applicable law, and, to the extent not so permitted, such purchase price may not
be less than par value. 
 (b) Legend. Each Participant receiving Restricted Stock shall be issued a stock certificate in respect of
such shares of Restricted Stock, unless the Committee elects to use another system, such as book entries by the transfer agent, as evidencing ownership of shares of Restricted Stock. Such certificate shall be registered in the name of such
Participant, and shall, in addition to such legends required by applicable securities laws, bear an appropriate legend referring to the terms, conditions, and restrictions applicable to such Award, substantially in the following form: 

  
 14 

 “The anticipation, alienation, attachment, sale, transfer, assignment, pledge,
encumbrance or charge of the shares of stock represented hereby are subject to the terms and conditions (including forfeiture) of the Altimmune, Inc. (the “Company”) 2018 Inducement Grant Plan (as amended from time to time,
the “Plan”), and an Award Agreement entered into between the registered owner and the Company dated                     .
Copies of such Plan and Agreement are on file at the principal office of the Company.” 
 (c) Custody. If stock certificates are
issued in respect of shares of Restricted Stock, the Committee may require that any stock certificates evidencing such shares be held in custody by the Company until the restrictions thereon shall have lapsed, and that, as a condition of any grant
of Restricted Stock, the Participant shall have delivered a duly signed stock power or other instruments of assignment (including a power of attorney), each endorsed in blank with a guarantee of signature if deemed necessary or appropriate by the
Company, which would permit transfer to the Company of all or a portion of the shares subject to the Award of Restricted Stock in the event that such Award is forfeited in whole or part. 

7.3 Restrictions and Conditions. Restricted Stock shall be subject to the following restrictions and conditions: 

(a) Restriction Period. The Participant shall not be permitted to Transfer shares of Restricted Stock, and the Restricted Stock shall be
subject to a risk of forfeiture (collectively, “restrictions”) during the period or periods set by the Committee (the “Restriction Periods”), as set forth in the Restricted Stock Award agreement. The Committee may
provide for the lapse of the restrictions in whole or in part (including in installments) based on service, attainment of performance goals or such other factors or criteria as the Committee may determine, and may waive all or any part of the
restrictions at any time. 
 (b) Rights as a Stockholder. Except as otherwise determined by the Committee, the Participant shall have
all the rights of a holder of shares of Common Stock of the Company with respect to Restricted Stock, subject to the following provisions of this Section 7.3(b). Except as otherwise determined by the Committee, (i) the Participant shall
have no right to tender shares of Restricted Stock, (ii) dividends or other distributions (collectively, “dividends”) on shares of Restricted Stock shall be withheld, in each case, while the Restricted Stock is subject to
restrictions, and (iii) in no event shall dividends or other distributions payable thereunder be paid unless and until the shares of Restricted Stock to which they relate no longer are subject to a risk of forfeiture. Dividends that are not
paid currently shall be credited to bookkeeping accounts on the Company’s records for purposes of the Plan and, except as otherwise determined by the Committee, shall not accrue interest. Such dividends shall be paid to the Participant in the
same form as paid on the Common Stock upon the lapse of the restrictions. The obligation of the Company to pay any dividends hereunder upon lapse of the applicable restrictions shall be a general, unsecured obligation of the Company payable solely
from the general assets of the Company. In no event shall the Company be required, or have any obligation, to set aside, or hold in escrow or trust, any funds for the purpose of paying such dividends. 

(c) Termination. Upon a Participant’s Termination for any reason during the Restriction Period, all Restricted Stock still subject
to restriction will vest or be forfeited in accordance with the terms and conditions established by the Committee at grant, or, if no rights of a Participant are reduced, thereafter. 

(d) Lapse of Restrictions. If and when the Restriction Period expires without a prior forfeiture of the Restricted Stock, the
certificates for such shares shall be delivered to the Participant, and any and all unpaid distributions or dividends payable thereunder shall be paid. All legends shall be removed from said certificates at the time of delivery to the Participant,
except as otherwise required by applicable law or other limitations imposed by the Committee. 

  
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 ARTICLE VIII 

OTHER STOCK-BASED AWARDS 
 8.1
Other Awards. The Committee is authorized to grant Other Stock-Based Awards that are payable in, valued in whole or in part by reference to, or otherwise based on or related to shares of Common
Stock, including shares of Common Stock not subject to any restrictions or conditions, stock appreciation rights, stock equivalent units, restricted stock units, Performance Shares, Performance Units and Awards valued by reference to book value of
shares of Common Stock. 
 The Committee shall have authority to determine the Participants to whom, and the time or times at which, Other
Stock-Based Awards shall be made, the number of shares of Common Stock to be awarded pursuant to such Awards, and all other terms and conditions of the Awards. 

The Committee may condition the grant or vesting of Other Stock-Based Awards upon the attainment of performance goals or such other factors as
the Committee may determine. 
 8.2 Terms and Conditions. Other Stock-Based Awards made pursuant to this Article VIII shall be
subject to the following terms and conditions: 
 (a) Non-Transferability. The Participant may
not Transfer Other Stock-Based Awards or the Common Stock underlying such Awards prior to the date on which the underlying Common Stock is issued, or, if later, the date on which any restriction, performance or deferral period applicable to such
Common Stock lapses. 
 (b) Dividends. The Committee shall determine to what extent, and under what conditions, the Participant shall
have the right to receive dividends, dividend equivalents or other distributions (collectively, “dividends”) with respect to shares of Common Stock covered by Other Stock-Based Awards. Except as otherwise determined by the Committee,
dividends with respect to unvested Other Stock-Based Awards shall be withheld until such Other Stock-Based Awards vest. Dividends that are not paid currently shall be credited to bookkeeping accounts on the Company’s records for purposes of the
Plan and, except as otherwise determined by the Committee, shall not accrue interest. Such dividends shall be paid to the Participant in the same form as paid on the Common Stock or such other form as is determined by the Committee upon the lapse of
the restrictions. The obligation of the Company to pay any dividends hereunder upon lapse of the applicable restrictions shall be a general, unsecured obligation of the Company payable solely from the general assets of the Company. In no event shall
the Company be required, or have any obligation, to set aside, or hold in escrow or trust, any funds for the purpose of paying such dividends. 

(c) Vesting. Other Stock Based Awards and any underlying Common Stock shall vest or be forfeited to the extent set forth in the
applicable Award agreement or as otherwise determined by the Committee. At the expiration of any applicable performance period, the Committee shall determine the extent to which the relevant performance goals are achieved and the portion of each
Other Stock-Based Award that has been earned. The Committee may, at or after grant, accelerate the vesting of all or any part of any Other Stock-Based Award. 

  
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 (d) Payment. Following the Committee’s determination in accordance with
subsection (c) above, shares of Common Stock or, as determined by the Committee, the cash equivalent of such shares, shall be delivered to the Participant, or his legal representative, in an amount equal to such individual’s earned Other
Stock-Based Award. Notwithstanding the foregoing, the Committee may exercise negative discretion by providing in an Other Stock-Based Award the discretion to pay an amount less than otherwise would be provided under the applicable level of
attainment of the performance goals or subject the payment of all or part of any Other Stock-Based Award to additional vesting, forfeiture and deferral conditions as it deems appropriate. 

(e) Detrimental Activity. Unless otherwise determined by the Committee in the applicable Award agreement, (A) in the event the
Participant engages in Detrimental Activity prior to any vesting of such Other Stock-Based Award, all unvested Other Stock-Based Award shall be immediately forfeited, and (B) in the event the Participant engages in Detrimental Activity during
the one year period after any vesting of such Other Stock-Based Award, the Committee shall be entitled to recover from the Participant (at any time within the one-year period after such engagement in
Detrimental Activity) an amount equal to any gain the Participant realized from any Other Stock-Based Award that had vested in the period referred to above. Unless otherwise determined by the Committee in the applicable Award agreement, this
Section 8.2(e) shall cease to apply upon a Change in Control. 
 (f) Price. Common Stock issued under this Article VIII may be
issued for no cash consideration; Common Stock purchased pursuant to a purchase right awarded under this Article VIII shall be priced as determined by the Committee. 

(g) Termination. Upon a Participant’s Termination for any reason during the applicable performance period, the Other Stock-Based
Awards will vest or be forfeited in accordance with the terms and conditions established by the Committee at grant or, if no rights of the Participant are reduced, thereafter. 

ARTICLE IX 
 CHANGE IN
CONTROL PROVISIONS 
 9.1 In the event of a Change in Control of the Company, except as otherwise provided by the Committee in an
Award agreement or otherwise in writing, a Participant’s unvested Award shall not vest and a Participant’s Award shall be treated in accordance with one of the following methods as determined by the Committee: 

(a) Awards, whether or not then vested, may be continued, assumed, have new rights substituted therefor or be treated in accordance with
Section 4.2(d), and Restricted Stock or other Awards may, where appropriate in the discretion of the Committee, receive the same distribution as other Common Stock on such terms as determined by the Committee; provided that, the
Committee may decide to award additional Restricted Stock or any other Award in lieu of any cash distribution. 
 (b) Awards may be canceled
in exchange for an amount of cash equal to the Change in Control Price (as defined below) per share of Common Stock covered by such Awards), less, in the case of an Appreciation Award, the exercise price per share of Common Stock covered by such
Award. The “Change in Control Price” means the price per share of Common Stock paid in the Change in Control transaction. 

  
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 (c) Appreciation Awards may be cancelled without payment, if the Change in Control Price is
less than the exercise price per share of such Appreciation Awards. 
 Notwithstanding anything else herein, the Committee may provide for accelerated
vesting or lapse of restrictions, of an Award at any time. 
 ARTICLE X 

TERMINATION OR AMENDMENT OF PLAN 

Notwithstanding any other provision of the Plan, the Board, or the Committee (to the extent permitted by law), may at any time, and from time
to time, amend, in whole or in part, any or all of the provisions of the Plan (including any amendment deemed necessary or advisable to ensure that the Company may comply with any regulatory requirement referred to in Article XII or
Section 409A), or suspend or terminate it entirely, retroactively or otherwise; provided, however, that, unless otherwise required by law or specifically provided herein, the rights of a Participant with respect to Awards granted
prior to such amendment, suspension or termination, may not be reduced in any material respect without the consent of such Participant. 

The Committee may amend the terms of any Award theretofore granted, prospectively or retroactively; provided that no such amendment
reduces in any material respect the rights of any Participant without the Participant’s consent. Actions taken by the Committee in accordance with Article IV shall not be deemed to reduce the rights of any Participant. 

Notwithstanding anything herein to the contrary, the Board or the Committee may amend the Plan or any Award at any time without a
Participant’s consent to comply with Section 409A or any other applicable law. 
 ARTICLE XI 

UNFUNDED PLAN 
 The Plan is
intended to constitute an “unfunded” plan for incentive and deferred compensation. With respect to any payments as to which a Participant has a fixed and vested interest but which are not yet made to a Participant by the Company, nothing
contained herein shall give any such Participant any rights that are greater than those of a general unsecured creditor of the Company. 

ARTICLE XII 
 GENERAL
PROVISIONS 
 12.1 Legend. The Committee may require each person receiving shares of Common Stock pursuant to an Award to
represent to and agree with the Company in writing that the Participant is acquiring the shares without a view to distribution thereof and such other securities law related representations as the Committee shall request. In addition to any legend
required by the Plan, the certificates or book entry accounts for such shares may include any legend that the Committee deems appropriate to reflect any restrictions on Transfer. 

  
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 All certificates or book entry accounts for shares of Common Stock delivered under the Plan
shall be subject to such stop transfer orders and other restrictions as the Committee may deem advisable under the rules, regulations and other requirements of the Securities and Exchange Commission, any stock exchange upon which the Common Stock is
then listed or any national automated quotation system on which the Common Stock is then quoted, any applicable federal or state securities law, and any applicable corporate law, and the Committee may cause a legend or legends to be put on any such
certificates to make appropriate reference to such restrictions. If necessary or advisable in order to prevent a violation of applicable securities laws or to avoid the imposition of public company reporting requirements, then, notwithstanding
anything herein to the contrary, any stock-settled Awards shall be paid in cash in an amount equal to the Fair Market Value on the date of settlement of such Awards. 

12.2 Other Plans. Nothing contained in the Plan shall prevent the Board from adopting other or additional compensation
arrangements, subject to stockholder approval if such approval is required; and such arrangements may be either generally applicable or applicable only in specific cases. 

12.3 No Right to Employment/Consultancy/Directorship. Neither the Plan nor the grant of any Award thereunder shall give any
Participant or other person any right to employment, consultancy or directorship by the Company or any Affiliate, or limit in any way the right of the Company or any Affiliate by which an employee is employed or a Consultant or Non-Employee Director is retained to terminate his employment, consultancy or directorship at any time. 

12.4 Withholding of Taxes. The Company or any Affiliate shall have the right to deduct from any payment to be made pursuant to
the Plan, or to otherwise require, prior to the issuance or delivery of any shares of Common Stock or the payment of any cash thereunder, payment by the Participant of, any federal, foreign, state or local taxes required by law to be withheld. Upon
the vesting of Restricted Stock (or other Award that is taxable upon vesting), or upon making an election under Section 83(b) of the Code, a Participant shall pay all required withholding to the Company or any Affiliate. Any statutorily
required withholding obligation with regard to any Participant may be satisfied, subject to the consent of the Committee, by reducing the number of shares of Common Stock otherwise deliverable or by delivering shares of Common Stock already owned.
Any fraction of a share of Common Stock required to satisfy such tax obligations shall be disregarded and the amount due shall be paid instead in cash by the Participant. 

12.5 No Assignment of Benefits. No Award or other benefit payable under the Plan shall, except as otherwise specifically provided
in the Plan or permitted by the Committee, be Transferable in any manner, and any attempt to Transfer any such benefit shall be void, and any such benefit shall not in any manner be liable for or subject to the debts, contracts, liabilities,
engagements or torts of any person who shall be entitled to such benefit, nor shall it be subject to attachment or legal process for or against such person. 

12.6 Listing and Other Conditions. (a) Unless otherwise determined by the Committee, as long as the Common Stock is listed on a
national securities exchange or system sponsored by a national securities association, the issuance of shares of Common Stock pursuant to an Award shall be conditioned upon such shares being listed on such exchange or system. The Company shall have
no obligation to issue such shares unless and until such shares are so listed, and the right to exercise any Stock Option or other Exercisable Award with respect to such shares shall be suspended until such listing has been effected. 

  
 19 

 (b) If at any time counsel to the Company shall be of the opinion that any offer or sale of
Common Stock pursuant to an Award is or may be unlawful or prohibited, or will or may result in the imposition of excise taxes on the Company, under the statutes, rules or regulations of any applicable jurisdiction or under the rules of the national
securities exchange on which the Common Stock then is listed, the Company shall have no obligation to make such offer or sale, or to make any application or to effect or to maintain any qualification or registration under the Securities Act or
otherwise, with respect to the Common Stock or Awards, and the right to exercise any Stock Option or other Exercisable Award shall be suspended until, in the opinion of said counsel, such offer or sale shall be lawful, permitted or will not result
in the imposition of excise taxes on the Company. 
 (c) Upon termination of any period of suspension under this Section 12.6, any Award
affected by such suspension which shall not then have expired or terminated shall be reinstated as to all shares available before such suspension and as to shares which would otherwise have become available during the period of such suspension, but
no such suspension shall extend the term of any Award. 
 (d) A Participant shall be required to supply the Company with certificates,
representations and information that the Company requests and otherwise cooperate with the Company in obtaining any listing, registration, qualification, exemption, consent or approval the Company deems necessary or appropriate. 

12.7 Governing Law. The Plan and matters arising under or related to it shall be governed by and construed in accordance with the
internal laws of the State of Delaware without giving effect to its principles of conflicts of laws. 
 12.8 Construction.
Wherever any words are used in the Plan in the masculine gender they shall be construed as though they were also used in the feminine gender in all cases where they would so apply. As used herein, (a) “or” shall mean
“and/or” and (b) “including” or “include” shall mean “including, without limitation.” Any reference herein to an agreement in writing shall be deemed to include an electronic writing to the extent
permitted by applicable law. 
 12.9 No Acquired Rights. In participating in the Plan, each Participant is deemed to
acknowledge and accept that the Committee has the sole discretion to amend or terminate the Plan, to the extent permitted hereunder, at any time and that the opportunity given to a Participant to participate in the Plan is at the sole discretion of
the Committee and does not obligate the Company or any Affiliate to offer such participation in the future (whether on the same or different terms). In participating in the Plan, each Participant is deemed further to acknowledge and accept that
(i) such Participant’s participation in the Plan is not to be considered part of any normal or expected compensation, (ii) the value of Awards granted to a Participant shall not be used for purposes of determining any benefits or
compensation payable to the Participant or the Participant’s beneficiaries or estate under any benefit arrangement of the Company or its Affiliates and (iii) the termination of the Participant’s employment with the Company or an
Affiliate under any circumstance whatsoever will not give the Participant any claim or right of action against the Company or any of its Affiliates in respect of any lost rights under the Plan that may arise as a result of such termination of
employment. 

  
 20 

 12.10 Data Protection. 

By participating in the Plan, each Participant shall consent to the holding and processing of personal information provided by such Participant
to the Company, any Affiliate, trustee or third-party service provider, for all purposes relating to the operation of the Plan. These include, but are not limited to: (i) administering and maintaining Participant records; (ii) providing
information to the Company, Affiliates, trustees of any employee benefit trust, registrars, brokers or third-party administrators of the Plan; (iii) providing information to future purchasers or merger partners of the Company or any Affiliate,
or the business in which the Participant works; and (iv) transferring personal information about the Participant to any country or territory that may not provide the same protection for the information as the Participant’s home country.
Such personal information may include, without limitation, the Participant’s name, home address and telephone number, date of birth, social insurance number or other identification number, salary, nationality, job title, any shares or
directorships held in the Company or an Affiliate and details of all Awards or other entitlement to shares awarded, canceled, exercised, vested, unvested or outstanding in a Participant’s favor. 

12.11 Costs. The Company shall bear all expenses associated with administering the Plan, including expenses of issuing Common
Stock pursuant to any Awards. 
 12.12 No Right to Same Benefits. The provisions of Awards need not be the same with respect to
each Participant, and each Award to an individual Participant need not be the same. 
 12.13 Death/Disability. The Committee
may require the transferee of a Participant to supply it with written notice of the Participant’s death or Disability and to supply it with a copy of the will (in the case of the Participant’s death) or such other evidence as the Committee
deems necessary or advisable to establish the validity of the transfer of an Award. The Committee also may require that the transferee agree to be bound by all of the terms and conditions of the Plan. 

12.14 Section 16(b) of the Exchange Act. All elections and transactions under the Plan by persons subject to Section 16 of
the Exchange Act involving shares of Common Stock are intended to comply with any applicable exemptive condition under Rule 16b-3. The Committee may establish and adopt written administrative guidelines,
designed to facilitate compliance with Section 16(b) of the Exchange Act, as it may deem necessary or advisable for the administration and operation of the Plan and the transaction of business thereunder. 

12.15 Section 409A. Although the Company does not guarantee to a Participant the particular tax treatment of any Award, all
Awards are intended to comply with, or be exempt from, the requirements of Section 409A and the Plan and any Award agreement shall be limited, construed and interpreted in accordance with such intent. To the extent that any Award constitutes “non-qualified deferred compensation” pursuant to Section 409A (a “Section 409A Covered Award”), it is intended to be paid in a manner that
will comply with Section 409A. In no event shall the Company be liable for any additional tax, interest or penalties that may be imposed on a Participant by Section 409A or for any damages for failing to comply with Section 409A.
Notwithstanding anything in the Plan or in an Award to the contrary, the following provisions shall apply to Section 409A Covered Awards: 

  
 21 

 (a) A termination of employment shall not be deemed to have occurred for purposes of any
provision of a Section 409A Covered Award providing for payment upon or following a termination of the Participant’s employment unless such termination is also a “separation from service” within the meaning of Section 409A
and, for purposes of any such provision of a Section 409A Covered Award, references to a “termination,” “termination of employment” or like terms shall mean separation from service. Notwithstanding any provision to the
contrary in the Plan or the Award, if the Participant is deemed on the date of the Participant’s Termination to be a “specified employee” within the meaning of that term under Section 409A(a)(2)(B) of the Code and using the
identification methodology selected by the Company from time to time, or if none, the default methodology set forth in Section 409A, then with regard to any such payment under a Section 409A Covered Award, to the extent required to be
delayed in compliance with Section 409A(a)(2)(B) of the Code, such payment shall not be made prior to the earlier of (i) the expiration of the six-month period measured from the date of the
Participant’s separation from service, and (ii) the date of the Participant’s death. All payments delayed pursuant to this Section 12.15(a) shall be paid to the Participant on the first day of the seventh month following the date
of the Participant’s separation from service or, if earlier, on the date of the Participant’s death. 
 (b) With respect to any
payment pursuant to a Section 409A Covered Award that is triggered upon a Change in Control, the settlement of such Award shall not occur until the earliest of (i) the Change in Control if such Change in Control constitutes a “change
in the ownership of the corporation,” a “change in effective control of the corporation” or a “change in the ownership of a substantial portion of the assets of the corporation,” within the meaning of
Section 409A(a)(2)(A)(v) of the Code, (ii) the date such Award otherwise would be settled pursuant to the terms of the applicable Award agreement and (iii) the Participant’s “separation from service” within the meaning
of Section 409A, subject to Section 12.15(a). 
 (c) For purposes of Code Section 409A, a Participant’s right to receive
any installment payments under the Plan or pursuant to an Award shall be treated as a right to receive a series of separate and distinct payments. 

(d) Whenever a payment under the Plan or pursuant to an Award specifies a payment period with reference to a number of days (e.g.,
“payment shall be made within 30 days following the date of termination”), the actual date of payment within the specified period shall be within the sole discretion of the Company. 

12.16 Successor and Assigns. The Plan shall be binding on all successors and permitted assigns of a Participant, including the
estate of such Participant and the executor, administrator or trustee of such estate. 
 12.17 Severability of Provisions. If
any provision of the Plan shall be held invalid or unenforceable, such invalidity or unenforceability shall not affect any other provisions hereof, and the Plan shall be construed and enforced as if such provisions had not been included. 

12.18 Participants Subject to Taxation outside the U.S.; No Tax Equalization. With respect to a Participant who is subject to
taxation in a country other than the United States, the Committee may grant Awards to such Participant on such terms and conditions as the Committee deems appropriate to comply with the laws of the applicable country, and the Committee may create
such procedures, addenda and subplans and make such modifications as may, in the Committee’s discretion, be necessary or desirable to comply with such laws. Neither the Company nor any Affiliate shall have any responsibility to such Participant
with respect to any taxes owed or owing in or to any jurisdiction that such Participant incurs as a result of receiving an Award and becoming a Participant in the Plan, nor shall the Company or any Affiliate provide any tax equalization payment to
any Participant in respect of taxes owed or owing in or to any jurisdiction by a Participant. 

  
 22 

 12.19 Payments to Minors, Etc. Any benefit payable to or for the benefit of a
minor, an incompetent person or other person incapable of receipt thereof shall be deemed paid when paid to such person’s guardian or to the party providing or reasonably appearing to provide for the care of such person, and such payment shall
fully discharge the Committee, the Board, the Company, its Affiliates and their employees, agents and representatives with respect thereto. 

12.20 Headings and Captions. The headings and captions herein are provided for reference and convenience only, shall not be
considered part of the Plan, and shall not be employed in the construction of the Plan. 
 12.21 Recoupment. All Awards granted
or other compensation paid by the Company under the Plan, including any shares of Common Stock issued under any Award thereunder, will be subject to: (i) any compensation recapture policies established by the Board or the Committee from time to
time and in effect at the time of grant of the Award, and (ii) any compensation recapture policies to the extent required pursuant to any applicable law (including the Dodd-Frank Act) or the rules and regulations of any national securities
exchange on which the shares of Common Stock are then traded. 
 12.22 Reformation. If any provision regarding Detrimental
Activity or any other provision set forth in the Plan or an Award agreement is found by any court of competent jurisdiction or arbitrator to be invalid, void or unenforceable or to be excessively broad as to duration, activity, geographic
application or subject, such provision or provisions shall be construed, by limiting or reducing them to the extent legally permitted, so as to be enforceable to the maximum extent compatible with then applicable law. 

12.23 Electronic Communications. Notwithstanding anything else herein to the contrary, any Award agreement, notice of exercise of
an Exercisable Award, or other document or notice required or permitted by the Plan or an Award that is required to be delivered in writing may, to the extent determined by the Committee, be delivered and accepted electronically. Signatures also may
be electronic if permitted by the Committee. The term “written agreement” as used in the Plan shall include any document that is delivered and/or accepted electronically. 

12.24 Agreement. As a condition to the grant of an Award, if requested by the Company and the lead underwriter of any public
offering of the Common Stock (the “Lead Underwriter”), a Participant shall irrevocably agree not to sell, contract to sell, grant any option to purchase, transfer the economic risk of ownership in, make any short sale of,
pledge or otherwise transfer or dispose of, any interest in any Common Stock or any securities convertible into, derivative of, or exchangeable or exercisable for Common Stock, or any other rights to purchase or acquire Common Stock (except Common
Stock included in such public offering or acquired on the public market after such offering) during such period of time following the effective date of a registration statement of the Company filed under the Securities Act that the Lead Underwriter
shall specify (the “Lock-up Period”). The Participant shall further agree to sign such documents as may be requested by the Lead Underwriter to effect the foregoing and agree that the
Company may impose stop-transfer instructions with respect to Common Stock acquired pursuant to an Award until the end of such Lock-up Period. 

  
 23 

 12.25 Defense of Trade Secrets Act. 

Pursuant to 18 USC § 1833(b), an individual may not be held criminally or civilly liable under any federal or state trade secret law for
disclosure of a trade secret made: (i) in confidence to a government official, either directly or indirectly, or to an attorney, solely for the purpose of reporting or investigating a suspected violation of law; and/or (ii) in a complaint
or other document filed in a lawsuit or other proceeding, if such filing is made under seal. Additionally, an individual suing an employer for retaliation based on the reporting of a suspected violation of law may disclose a trade secret to his
attorney and use the trade secret information in the court proceeding, so long as any document containing the trade secret is filed under seal and the individual does not disclose the trade secret except pursuant to court order. 

ARTICLE XIII 
 EFFECTIVE
DATE OF PLAN; STOCKHOLDER APPROVAL NOT REQUIRED 
 The Plan was adopted by the Board effective as of November 30, 2018 (the
“Effective Date”). 
 It is expressly intended that approval of the Company’s stockholders not be required as a
condition of the effectiveness of the Plan, and the Plan’s provisions shall be interpreted in a manner consistent with such intent for all purposes. Specifically, Nasdaq Stock Market Rule 5635(c) generally requires stockholder approval for
stock option plans or other equity compensation arrangements adopted by companies whose securities are listed on the Nasdaq Stock Market pursuant to which stock awards or stock may be acquired by officers, directors, employees or consultants of such
companies. Nasdaq Stock Market Rule 5635(c)(4) provides an exception to this requirement for issuances of securities to a person not previously an employee or director of the issuer, or following a bona fide period of non-employment, as an inducement material to the individual’s entering into employment with the issuer; provided, that such issuances are approved by either the issuer’s compensation committee comprised of
a majority of independent directors or a majority of the issuer’s independent directors. Notwithstanding anything to the contrary herein, Awards under the Plan may only be made to Employees who have not previously been an Employee or Non-Employee Director of the Company or a Subsidiary, or following a bona fide period of non-employment by the Company or a Subsidiary, as an inducement material to the
Employee’s entering into employment with the Company or a Subsidiary. Awards under the Plan will be approved by (i) the Committee, comprised of a majority of independent directors, or (ii) a majority of the Company’s independent
directors. Accordingly, pursuant to Nasdaq Stock Market Rule 5635(c)(4), the issuance of Awards and the shares of Common Stock issuable upon exercise or vesting of such Awards pursuant to the Plan are not subject to the approval of the
Company’s stockholders. 
 ARTICLE XIV 

TERM OF PLAN 
 No Award shall be
granted on or after the tenth anniversary of the Effective Date, provided that Awards granted prior to such tenth anniversary may extend beyond that date in accordance with the terms of the Plan. 

  
 24EX-10.4

 Exhibit 10.4 

NONQUALIFIED STOCK OPTION AGREEMENT 

PURSUANT TO THE 

ALTIMMUNE, INC. 2018 INDUCEMENT GRANT PLAN 

*   *   *  *  * 

Participant: 
 Grant Date: 

Per Share Exercise Price: $[•] 
 Number of Shares of Common
Stock subject to this Option: [•] 
  

			
	Vesting schedule:	  	Provided that the Participant has not incurred a Termination prior to the applicable vesting date, twenty-five percent (25%) of the shares underlying the Option shall become vested and exercisable on the first anniversary of the
Grant Date (the “First Vesting Date”) and the remaining seventy-five percent (75%) of the shares underlying the Option shall become vested and exercisable in thirty-six (36) substantially
equal monthly installments on each monthly anniversary of such First Vesting Date, such that the Option will be fully vested on [•]. There shall be no proportionate or partial vesting in the periods prior to the applicable vesting date(s) and
all vesting shall occur only on the applicable vesting date(s).

 *  *  *  *  * 

THIS NON-QUALIFIED STOCK OPTION AWARD AGREEMENT (this “Agreement”), dated as of the
Grant Date specified above, is entered into by and between Altimmune, Inc., a Delaware corporation (the “Company”), and the Participant specified above, pursuant to the Altimmune, Inc. 2018 Inducement Grant Plan, as in effect
and as amended from time to time (the “Plan”), which is administered by the Committee; and 
 WHEREAS, it has been
determined under the Plan that it would be in the best interests of the Company to grant the non-qualified stock option provided for herein to the Participant. 

NOW, THEREFORE, in consideration of the mutual covenants and promises hereinafter set forth and for other good and valuable consideration, the
parties hereto hereby mutually covenant and agree as follows: 
 1. Incorporation by Reference; Plan Document Receipt. This
Agreement is subject in all respects to the terms and provisions of the Plan (including, without limitation, any amendments thereto adopted at any time and from time to time unless such amendments are expressly intended not to apply to the award
provided hereunder), all of which terms and provisions are made a part of and incorporated in this Agreement as if they were each expressly set forth herein. Any capitalized term not defined in this Agreement shall have the same meaning as is
ascribed thereto in the Plan. The Participant hereby acknowledges receipt of a true copy of the Plan and that the Participant has read the Plan carefully and fully understands its content. In the event of any conflict between the terms of this
Agreement and the terms of the Plan, the terms of the Plan shall control. No part of the Option granted hereby is intended to qualify as an “incentive stock option” under Section 422 of the Code. 

 2. Grant of Option. The Company hereby grants to the Participant, as of the
Grant Date specified above, a non-qualified stock option (this “Option”) to acquire from the Company at the Per Share Exercise Price specified above, the aggregate number of shares of Common
Stock specified above (the “Option Shares”). Except as otherwise provided by the Plan, the Participant agrees and understands that nothing contained in this Agreement provides, or is intended to provide, the Participant with any
protection against potential future dilution of the Participant’s interest in the Company for any reason. The Participant shall have no rights as a stockholder with respect to any shares of Common Stock covered by this Option unless and until
the Participant has become the holder of record of the shares of Common Stock, and no adjustments shall be made for dividends in cash or other property, distributions or other rights in respect of any such shares, except as otherwise specifically
provided for in the Plan or this Agreement. 
 3. Vesting; Detrimental Activity; Expiration. 

(a) Vesting. The Option subject to this grant shall become vested in accordance with the vesting schedule specified above. All vesting
of the Option granted hereunder shall occur only on the appropriate vesting date specified above, subject to the Participant’s continued service with the Company or any of its Subsidiaries through each applicable vesting date. There shall be no
proportionate or partial vesting in the periods prior to each vesting date. Notwithstanding anything herein or in the Plan to the contrary, if the Participant’s employment agreement with the Company provides for accelerated vesting in certain
circumstances, such accelerated vesting provisions shall control and be incorporated into this Agreement by reference. 
 (b) Effect of
Detrimental Activity. The provisions of Section 6.2(c)(ii) of the Plan regarding Detrimental Activity shall apply to the Option. The Participant acknowledges and agrees that the restrictions herein and in the Plan regarding Detrimental
Activity are necessary for the protection of the business and goodwill of the Company and its Affiliates, and are considered by the Participant to be reasonable for such purposes. Without intending to limit the legal or equitable remedies available
in the Plan and in this Agreement, the Participant acknowledges that engaging in Detrimental Activity will cause the Company and its Affiliates material irreparable injury for which there is no adequate remedy at law, that it will not be possible to
measure damages for such injuries precisely and that, in the event of such activity or threat thereof, the Company shall be entitled, in addition to the remedies provided under the Plan, to obtain from any court of competent jurisdiction a temporary
restraining order or a preliminary or permanent injunction restraining the Participant from engaging in Detrimental Activity or such other relief as may be required to specifically enforce any of the covenants in the Plan and this Agreement without
the necessity of posting a bond, and in the case of a temporary restraining order or a preliminary injunction, without having to prove special damages. 

(c) Expiration. The term of the Option shall be until the tenth anniversary of the Grant Date, after which time it shall expire (such
tenth anniversary date, the “Expiration Date”), subject to earlier termination in the event of the Participant’s Termination as specified in the Plan and this Agreement. Upon the Expiration Date, the Option (whether vested or
not) shall automatically be cancelled for no consideration, shall no longer be exercisable, and shall cease to be outstanding. 
 4.
Termination. Subject to the terms of the Plan and this Agreement, the Option, to the extent vested at the time of the Participant’s Termination, shall remain exercisable as follows: 

(a) Termination due to Death or Disability. In the event of the Participant’s Termination by reason of death or Disability, the
vested portion of this Option shall remain exercisable until the earlier of (i) one year from the date of such Termination, and (ii) the Expiration Date. 

(b) Termination without Cause. In the event of the Participant’s involuntary Termination by the Company without Cause, the vested
portion of this Option shall remain exercisable until the earlier of (i) ninety (90) days from the date of such Termination, and (ii) the Expiration Date. 

  
 2 

 (c) Voluntary Termination. In the event of the Participant’s voluntary
Termination, the vested portion of this Option shall remain exercisable until the earlier of (i) thirty (30) days from the date of such Termination, and (ii) the Expiration Date. 

(d) Termination for Cause. In the event of the Participant’s Termination by the Company for Cause (or in the event of a
voluntary Termination by the Participant after the occurrence of an event that would be grounds for a Termination for Cause), the Option granted hereunder (whether or not vested) shall terminate and expire upon such Termination. 

(e) Treatment of Unvested Option upon Termination. Any portion of this Option that is not vested as of the date of the
Participant’s Termination for any reason shall terminate and expire as of the date of such Termination. 
 5. Method of Exercise
and Payment. Subject to Section 8 hereof, to the extent that the Option has become vested and exercisable with respect to a number of shares of Common Stock as provided herein, the Option may thereafter be exercised by the Participant,
in whole or in part, at any time or from time to time prior to the expiration of the Option as provided herein and in accordance with Section 6.2 of the Plan, including, without limitation, by the delivery of any form of exercise notice as may
be required by the Committee and payment in full of the Per Share Exercise Price multiplied by the number of shares of Common Stock underlying the portion of the Option exercised. 

6. Non-transferability. The Option, and any rights and interests with respect
thereto, issued under this Agreement and the Plan shall not, prior to vesting, be sold, exchanged, Transferred, assigned or otherwise disposed of in any way by the Participant (or any beneficiary(ies) of the Participant), other than by testamentary
disposition by the Participant or the laws of descent and distribution. Notwithstanding the foregoing, the Committee may, in its sole discretion, permit the Option to be Transferred to a Family member for no value, provided that such Transfer shall
only be valid upon execution of a written instrument in form and substance acceptable to the Committee in its sole discretion evidencing such Transfer and the transferee’s acceptance thereof signed by the Participant and the transferee, and
provided, further, that the Option may not be subsequently Transferred otherwise than by will or by the laws of descent and distribution or to another Family Member (as permitted by the Committee in its sole discretion) in accordance with the terms
of the Plan and this Agreement, and shall remain subject to the terms of the Plan and this Agreement. Any attempt to sell, exchange, Transfer, assign, pledge, encumber or otherwise dispose of or hypothecate in any way the Option, or the levy of any
execution, attachment or similar legal process upon the Option, contrary to the terms and provisions of this Agreement and/or the Plan shall be null and void and without legal force or effect. 

7. Governing Law. All questions concerning the construction, validity and interpretation of this Agreement shall be governed by,
and construed in accordance with, the laws of the State of Delaware, without regard to choice of law principles (whether of the State of Delaware or otherwise) that would result in the application of the law of any other jurisdiction. 

8. Withholding of Tax. The Company or any Affiliate shall have the power and the right to deduct or withhold, require
the Participant to remit to the Company or such Affiliate, or make any other arrangements as it considers appropriate to ensure that it has received, an amount sufficient to satisfy any federal, state, local and foreign taxes of any kind (including,
but not limited to, the Participant’s FICA and SDI obligations) which the Company, in its sole discretion, deems necessary to be withheld or remitted to comply with the Code and/or any other applicable law, rule or regulation with respect to
the Option and, if the Participant fails to do so, the Company may otherwise refuse to issue or Transfer any shares of Common Stock otherwise required to be issued pursuant to this Agreement. 

  
 3 

 9. Recoupment Policy. The Participant acknowledges and agrees that this Option
(including any shares of Common Stock issued upon exercise thereof) shall be subject to the terms and provisions of any “clawback” or recoupment policy that may be adopted by the Company or its Affiliates from time to time or as may be
required by any applicable law (including, without limitation, the Dodd-Frank Wall Street Reform and Consumer Protection Act and implementing rules and regulations thereunder). 

10. Notices. Any notice or communication given hereunder shall be in writing and shall be deemed to have been duly given:
(i) when delivered in person; (ii) two (2) days after being sent by United States mail; or (iii) on the first business day following the date of deposit if delivered by a nationally recognized overnight delivery service, in each case,
to the appropriate party at the address set forth below (or such other address as the party may from time to time specify): 

If to the Company, to: 

Altimmune, Inc. 
 910 Clopper
Road, Suite 201S 
 Gaithersburg, MD 20878 

Attention: Board of Directors 

with a copy (which shall not constitute notice) to: 

Proskauer Rose LLP 
 One
International Place 
 Boston, MA 02110 

Attention: Ori Solomon, Esq. 

If to the Participant, to the address on file with the Company. 

11. No Right to Employment. Nothing contained in this Agreement shall affect the right of the Company or any of its Affiliates to
terminate the Participant’s employment at any time, with or without Cause, or shall be deemed to create any rights to employment or continued employment. The rights and obligations arising under this Agreement are not intended to and do not
affect the Participant’s employment relationship that otherwise exists between the Participant and the Company or any of its Affiliates, whether such employment relationship is at will or defined by an employment contract. Moreover, this
Agreement is not intended to and does not amend any existing employment contract between the Participant and the Company or any of its Affiliates; to the extent there is a conflict between this Agreement and such an employment contract, the
employment contract shall govern and take priority. 
 12. Data Protection. By executing this Agreement, the
Participant hereby consents to the holding and processing of personal information provided by the Participant to the Company, any Affiliate thereof, trustee or third party service provider, for all purposes relating to the operation of the Plan.
These include, but are not limited to: (i) administering and maintaining Participant records; (ii) providing information to the Company, its Affiliates, trustees of any employee benefit trust, registrars, brokers or third party
administrators of the Plan; (iii) providing information to future purchasers or merger partners of the Company or any Affiliate thereof, or the business in which the Participant works; and (iv) transferring information about the
Participant to any country or territory that may not provide the same protection for the information as the Participant’s home country. 

13. Market Stand-Off. If requested by the Company, any Affiliate or the lead underwriter
of any public offering of the shares of Common Stock (the “Lead Underwriter”), the Participant shall irrevocably agree not to sell, contract to sell, grant any option to purchase, transfer the economic risk of ownership in, make any
short sale of, pledge or otherwise Transfer or dispose of, any interest in any shares of Common Stock or any securities convertible into, derivative of, or exchangeable or exercisable for shares of Common Stock, or any other rights to purchase or
acquire shares of Common Stock (except shares of 

  
 4 

 
Common Stock included in such public offering or acquired on the public market after such offering) during such period of time following the effective date of a registration statement of the
Company filed under the Securities Act that the Lead Underwriter shall specify (the “Lock-up Period”). The Participant shall further agree to sign such documents as may be requested by the
Lead Underwriter, the Company or any Affiliate to effect the foregoing and agree that the Company or an Affiliate may impose stop transfer instructions with respect to shares of Common Stock acquired pursuant to an Award until the end of such Lock-up Period. 
 14. Compliance with Laws. The issuance of this Option (and the shares of
Common Stock upon exercise of this Option) pursuant to this Agreement shall be subject to, and shall comply with, any applicable requirements of any foreign and U.S. federal and state securities laws, rules and regulations (including, without
limitation, the provisions of the Securities Act, the Exchange Act and in each case any respective rules and regulations promulgated thereunder) and any other law or regulation applicable thereto. The Company shall not be obligated to issue this
Option or any of the shares of Common Stock pursuant to this Agreement if any such issuance would violate any such requirements. 
 15.
Section 409A. Notwithstanding anything herein or in the Plan to the contrary, the Option is intended to be exempt from the applicable requirements of Section 409A and shall be limited, construed
and interpreted in accordance with such intent. 
 16. Binding Agreement; Assignment. This Agreement shall inure to the benefit
of, be binding upon, and be enforceable by the Company and its successors and assigns. The Participant shall not assign any part of this Agreement without the prior express written consent of the Company. 

17. Headings. The titles and headings of the various sections of this Agreement have been inserted for convenience of reference
only and shall not be deemed to be a part of this Agreement. 
 18. Counterparts. This Agreement may be executed in
one or more counterparts, each of which shall be deemed to be an original, but all of which shall constitute one and the same instrument. 

19. Severability. The invalidity or unenforceability of any provisions of this Agreement in any jurisdiction shall not affect the
validity, legality or enforceability of the remainder of this Agreement in such jurisdiction or the validity, legality or enforceability of any provision of this Agreement in any other jurisdiction, it being intended that all rights and obligations
of the parties hereunder shall be enforceable to the fullest extent permitted by law. 
 20. Entire Agreement; Amendment. This
Agreement, together with the Plan, contains the entire agreement between the parties hereto with respect to the subject matter contained herein, and supersedes all prior agreements or prior understandings, whether written or oral, between the
parties relating to such subject matter. The Committee shall have the right, in its sole discretion, to modify or amend this Agreement from time to time in accordance with and as provided in the Plan. This Agreement may also be modified or amended
by a writing signed by both the Company and the Participant. The Company shall give written notice to the Participant of any such modification or amendment of this Agreement as soon as practicable after the adoption thereof. 

21. Mode of Communications. The Participant agrees, to the fullest extent permitted by applicable law, in lieu of receiving
documents in paper format, to accept electronic delivery of any documents that the Company or any of its Affiliates may deliver in connection with this Option grant and any other grants offered by the Company or its Affiliates, including, without
limitation, prospectuses, grant notifications, account statements, annual or quarterly reports, and other communications. Electronic delivery of a document may be made via the Company’s email system or by reference to a location on the
Company’s intranet or website or the online brokerage account system. 

  
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 22. Acquired Rights. The Participant acknowledges and agrees that:
(a) the Company may terminate or amend the Plan at any time; (b) the award of the Option made under this Agreement is completely independent of any other award or grant and is made at the sole discretion of the Company; (c) no past
grants or awards (including, without limitation, the Option awarded hereunder) give the Participant any right to any grants or awards in the future whatsoever; and (d) any benefits granted under this Agreement are not part of the
Participant’s ordinary salary, and shall not be considered as part of such salary in the event of severance, redundancy or resignation. 

23. Participant Acknowledgment. The Participant agrees that the Participant has not been previously employed in any capacity by
the Company or a Subsidiary, or if previously employed, has had a bona fide period of non-employment, and that the grant of this Option is an inducement material to the Participant’s agreement to
enter into employment with the Company or Subsidiary. The Participant acknowledges that the Plan is intended to conform with the requirements of rules promulgated by the Nasdaq Stock Market and, without limiting the foregoing, in particular Nasdaq
Stock Market Rule 5635(c). The Participant further acknowledges that the Plan will not be submitted for approval by the Company’s stockholders. As more particularly described in Article XIII of the Plan, pursuant to Nasdaq Stock Market Rule
5635(c), the issuance of this Option and the shares of Common Stock issuable upon the exercise or vesting of such Option pursuant to the Plan are not subject to the approval of the Company’s stockholders. 

[Remainder of Page Intentionally Left Blank] 

  
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 IN WITNESS WHEREOF, the parties hereto have executed this Agreement as of the date
first written above. 
  

			
	ALTIMMUNE, INC.
		
	By:	 	
                     
                                

	Name:	 	  

	Title:	 	  

	
	PARTICIPANT
	
	  

	Name:	 	  

	Social Security Number:
                                         
   

  
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