Exhibit 4.3




 


[Form of Warrant Certificate]


[FACE]


 


Number


 


Warrants


 


THIS WARRANT SHALL BE VOID IF NOT EXERCISED
PRIOR TO


THE EXPIRATION OF THE EXERCISE PERIOD
PROVIDED FOR


IN THE WARRANT AGREEMENT DESCRIBED BELOW


BIOTECH ACQUISITION COMPANY


 


Incorporated Under the Laws of the Cayman
Islands


 


CUSIP G1125A 116


 


Warrant Certificate


 


This Warrant Certificate certifies
that , or registered assigns, is the registered holder of warrant(s) evidenced hereby (the “Warrants”
and each, a “Warrant”) to purchase Class A ordinary shares, of $0.001 par value per share (“Ordinary Shares”),
of Biotech Acquisition Company, a Cayman Islands exempted company (the “Company”). Each Warrant entitles
the holder, upon exercise during the period set forth in the Warrant Agreement referred to below, to receive from the Company that
number of fully paid and non-assessable Ordinary Shares as set forth below, at the exercise price (the “Warrant Price”)
as determined pursuant to the Warrant Agreement, payable in lawful money (or through “cashless exercise”
as provided for in the Warrant Agreement) of the United States of America upon surrender of this Warrant Certificate and payment
of the Warrant Price at the office or agency of the Warrant Agent referred to below, subject to the conditions set forth herein
and in the Warrant Agreement. Defined terms used in this Warrant Certificate but not defined herein shall have the meanings given
to them in the Warrant Agreement.


 


Each whole Warrant is initially exercisable
for one fully paid and non-assessable Ordinary Share. No fractional shares will be issued upon exercise of any Warrant. If, upon
the exercise of Warrants, a holder would be entitled to receive a fractional interest in an Ordinary Share, the Company will, upon
exercise, round down to the nearest whole number of Ordinary Shares to be issued to the Warrant holder. The number of Ordinary
Shares issuable upon exercise of the Warrants is subject to adjustment upon the occurrence of certain events set forth in the Warrant
Agreement.


 


The initial Warrant Price per Ordinary Share
for any Warrant is equal to $11.50 per share. The Warrant Price is subject to adjustment upon the occurrence of certain events
set forth in the Warrant Agreement.


 


Subject to the conditions set forth in the
Warrant Agreement, the Warrants may be exercised only during the Warrant Period and to the extent not exercised by the end of such
Exercise Period, such Warrants shall become void.


 


Reference is hereby made to the further
provisions of this Warrant Certificate set forth on the reverse hereof and such further provisions shall for all purposes have
the same effect as though fully set forth at this place.


 


This Warrant Certificate shall not be valid
unless countersigned by the Warrant Agent, as such term is used in the Warrant Agreement.


 


This Warrant Certificate shall be governed
by and construed in accordance with the internal laws of the State of New York, without regard to conflicts of laws principles
thereof.


 


	 	BIOTECH ACQUISITION COMPANY
	 	 	 
	 	By:	 
	 	Name:	 
	 	Title:	 
	 	 	 
	 	 	 
	 	CONTINENTAL STOCK TRANSFER & TRUST COMPANY, as Warrant Agent
	 	 	 
	 	By:	 
	 	Name:	 
	 	Title:	 



 










     


     


    

 


[Form of Warrant Certificate]


[Reverse]


 


The Warrants evidenced by this Warrant Certificate
are part of a duly authorized issue of Warrants entitling the holder on exercise to receive Ordinary Shares and are issued or to
be issued pursuant to a Warrant Agreement dated as of , 2021 (the “Warrant Agreement”), duly executed
and delivered by the Company to Continental Stock Transfer & Trust Company, a New York corporation, as warrant agent (the “Warrant
Agent”), which Warrant Agreement is hereby incorporated by reference in and made a part of this instrument and is
hereby referred to for a description of the rights, limitation of rights, obligations, duties and immunities thereunder of the
Warrant Agent, the Company and the holders (the words “holders” or “holder”
meaning the Registered Holders or Registered Holder, respectively) of the Warrants. A copy of the Warrant Agreement may be obtained
by the holder hereof upon written request to the Company. Defined terms used in this Warrant Certificate but not defined herein
shall have the meanings given to them in the Warrant Agreement.


 


Warrants may be exercised at any time during
the Exercise Period set forth in the Warrant Agreement. The holder of Warrants evidenced by this Warrant Certificate may exercise
them by surrendering this Warrant Certificate, with the form of election to purchase set forth hereon properly completed and executed,
together with payment of the Warrant Price as specified in the Warrant Agreement (or through “cashless exercise” as
provided for in the Warrant Agreement) at the principal corporate trust office of the Warrant Agent. In the event that upon any
exercise of Warrants evidenced hereby the number of Warrants exercised shall be less than the total number of Warrants evidenced
hereby, there shall be issued to the holder hereof or his, her or its assignee, a new Warrant Certificate evidencing the number
of Warrants not exercised.


 


Notwithstanding anything else in this Warrant
Certificate or the Warrant Agreement, no Warrant may be exercised unless at the time of exercise (i) a registration statement covering
the Ordinary Shares to be issued upon exercise is effective under the Securities Act and (ii) a prospectus thereunder relating
to the Ordinary Shares is current, except through “cashless exercise” as provided for in the Warrant Agreement.


 


The Warrant Agreement provides that upon
the occurrence of certain events the number of Ordinary Shares issuable upon exercise of the Warrants set forth on the face hereof
may, subject to certain conditions, be adjusted. If, upon exercise of a Warrant, the holder thereof would be entitled to receive
a fractional interest in an Ordinary Share, the Company shall, upon exercise, round down to the nearest whole number of Ordinary
Shares to be issued to the holder of the Warrant.


 


Warrant Certificates, when surrendered at
the principal corporate trust office of the Warrant Agent by the Registered Holder thereof in person or by legal representative
or attorney duly authorized in writing, may be exchanged, in the manner and subject to the limitations provided in the Warrant
Agreement, but without payment of any service charge, for another Warrant Certificate or Warrant Certificates of like tenor evidencing
in the aggregate a like number of Warrants.


 


Upon due presentation for registration of
transfer of this Warrant Certificate at the office of the Warrant Agent a new Warrant Certificate or Warrant Certificates of like
tenor and evidencing in the aggregate a like number of Warrants shall be issued to the transferee(s) in exchange for this Warrant
Certificate, subject to the limitations provided in the Warrant Agreement, without charge except for any tax or other governmental
charge imposed in connection therewith.


 


The Company and the Warrant Agent may deem
and treat the Registered Holder(s) hereof as the absolute owner(s) of this Warrant Certificate (notwithstanding any notation of
ownership or other writing hereon made by anyone), for the purpose of any exercise hereof, of any distribution to the holder(s)
hereof, and for all other purposes, and neither the Company nor the Warrant Agent shall be affected by any notice to the contrary.
Neither the Warrants nor this Warrant Certificate entitles any holder hereof to any rights of a shareholder of the Company.


 






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Election to Purchase


(To Be Executed Upon Exercise of Warrant)


 


The undersigned hereby irrevocably elects
to exercise the right, represented by this Warrant Certificate, to receive Ordinary Shares and herewith tenders payment for such
Ordinary Shares to the order of Biotech Acquisition Company (the “Company”) in the amount of $ in accordance
with the terms hereof. The undersigned requests that a certificate for such Ordinary Shares be registered in the name of , whose
address is and that such Ordinary Shares be delivered to whose address is . If said number of Ordinary Shares is less than all
of the Ordinary Shares purchasable hereunder, the undersigned requests that a new Warrant Certificate representing the remaining
balance of such Ordinary Shares be registered in the name of , whose address is and that such Warrant Certificate be delivered
to , whose address is .


 


In the event that the Warrant has been called
for redemption by the Company pursuant to Section 6 of the Warrant Agreement and the Company has required cashless exercise
pursuant to Section 6.3 of the Warrant Agreement, the number of Ordinary Shares that this Warrant is exercisable for shall
be determined in accordance with subsection 3.3.1(b) and Section 6.3 of the Warrant Agreement.


 


In the event that the Warrant is a Private
Placement Warrant or Working Capital Warrant that is to be exercised on a “cashless” basis pursuant to subsection
3.3.1(c) of the Warrant Agreement, the number of Ordinary Shares that this Warrant is exercisable for shall be determined in
accordance with subsection 3.3.1(c) of the Warrant Agreement.


 


In the event that the Warrant is to be exercised
on a “cashless” basis pursuant to Section 7.4 of the Warrant Agreement, the number of Ordinary Shares that this
Warrant is exercisable for shall be determined in accordance with Section 7.4 of the Warrant Agreement.


 


In the event that the Warrant may be exercised,
to the extent allowed by the Warrant Agreement, through cashless exercise (i) the number of Ordinary Shares that this Warrant is
exercisable for would be determined in accordance with the relevant section of the Warrant Agreement which allows for such cashless
exercise and (ii) the holder hereof shall complete the following: The undersigned hereby irrevocably elects to exercise the right,
represented by this Warrant Certificate, through the cashless exercise provisions of the Warrant Agreement, to receive Ordinary
Shares. If said number of Ordinary Shares is less than all of the Ordinary Shares purchasable hereunder (after giving effect to
the cashless exercise), the undersigned requests that a new Warrant Certificate representing the remaining balance of such Ordinary
Shares be registered in the name of , whose address is and that such Warrant Certificate be delivered to , whose address is .


 


 


[Signature Page Follows]


 


	Date: , 20	 	 
	 	 	(Signature)
	 	 	 
	 	 	 
	 	 	 
	 	 	 
	 	 	(Address)
	 	 	 
	 	 	 
	 	 	(Tax Identification Number)
	 	 	 
	Signature Guaranteed:	 	 
	 	 	 
	 	 	 


 


THE SIGNATURE(S) SHOULD BE GUARANTEED BY AN ELIGIBLE GUARANTOR
INSTITUTION (BANKS, STOCKBROKERS, SAVINGS AND LOAN ASSOCIATIONS AND CREDIT UNIONS WITH MEMBERSHIP IN AN APPROVED SIGNATURE GUARANTEE
MEDALLION PROGRAM, PURSUANT TO S.E.C. RULE 17Ad-15 UNDER THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED (OR ANY SUCCESSOR RULE)).


 




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