For more information: www.cdc.gov/COVID19

Clinical Considerations for Use of 

COVID-19 Vaccines

Jessica MacNeil, MPH

March 1, 2021

ACIP COVID-19 Vaccines Work Group
 CDC clinical considerations for mRNA COVID-19 

vaccines published previously:

– https://www.cdc.gov/vaccines/covid-19/info-byproduct/clinical-considerations.html

 Clinical considerations are being updated to 

include Janssen COVID-19 vaccine

– Viral vector COVID-19 vaccine

Clinical considerations for use of mRNA COVID-19 vaccines

2 Sign up to receive email updates when clinical considerations are updated: https://www.cdc.gov/vaccines/covid-19/info-by-product/clinical -considerations.html
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Vaccine administration
 COVID-19 vaccines are administered intramuscularly as either a two-dose series or 

single dose

 One valid vaccination series should be completed

Administration of COVID-19 vaccines

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Vaccine Authorized 

age group

Dose Dose 

volume

Number

doses/series

Interval 

between 

doses

PfizerBioNTech≥16 years 30 μg 0.3 ml 2 3 weeks

(21 days)

Moderna ≥18 years 100 μg 0.5 ml 2 1 month

(28 days)

Janssen ≥18 years 5×1010 virus

particles

0.5 ml 1 N/A
 Any COVID-19 vaccine can be used when indicated; no product preference

 COVID-19 vaccines are not interchangeable

–

–

–

Safety and efficacy of a mixed series has not been evaluated

 If first dose of mRNA COVID-19 vaccine was received but patient unable to compete 

series with same or different mRNA vaccine (e.g., contraindication)

Single dose of Janssen COVID-19 vaccine may be administered at minimum interval of 28 

days from mRNA dose*

Considered to have received valid, single-dose Janssen vaccination, not mixed vaccination 

series (mRNA/viral vector)

Interchangeability of COVID-19 vaccine products

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*Persons with a contraindication to mRNA COVID-19 vaccines have a precaution to Janssen COVID-19 vaccine. In these patients, vaccination should be undertaken in an 

appropriate setting under the supervision of a health care provider experienced in the management of severe allergic reactions. Consider referral to allergist-immunologist.
 Currently authorized COVID-19 vaccines are all inactivated vaccines

 COVID-19 vaccine should be administered alone with minimum interval of 14 days 

before or after administration of other vaccines

 A shorter interval may be used in situations where the benefits of vaccination are 

deemed to outweigh the potential unknown risks (e.g., tetanus toxoid vaccine for 

wound management, etc.) or to avoid barriers or delays to vaccination

Coadministration of COVID-19 vaccines with other vaccines

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COVID-19 vaccination and SARS-CoV-2 

infection 
 Vaccination should be offered to persons regardless of history of prior symptomatic or 

asymptomatic SARS-CoV-2 infection

– Data from clinical trials indicate vaccination safe in these persons

 Viral testing for current infection, or serologic testing for prior infection, is not

recommended for the purpose of vaccine decision-making

Persons with prior SARS-CoV-2 infection

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 Vaccination should be deferred until recovery from acute illness (if person had 

symptoms) and criteria have been met to discontinue isolation

 No minimal interval between infection and vaccination

 Current evidence suggests reinfection uncommon in the months after initial 

infection, thus while vaccine supply remains limited, persons with recent documented 

infection may choose to temporarily delay vaccination

– Risk of reinfection, and need for vaccination, might increase with time following initial 

infection

Persons with known current SARS-CoV-2 infection

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https://www.cdc.gov/coronavirus/2019-ncov/hcp/disposition-in-home-patients.html

https://www.cdc.gov/coronavirus/2019-ncov/hcp/duration-isolation.html
 Currently no data on safety and efficacy of COVID-19 vaccination in persons who 

received monoclonal antibodies or convalescent plasma as part of COVID-19 treatment

 Vaccination should be deferred for at least 90 days to avoid interference of the passive 

antibody therapy with vaccine-induced immune responses

 Recommendation does not apply to persons receiving antibody therapies not specific to 

COVID-19 treatment

Persons who previously received passive antibody therapy 

for COVID-19

https://www.cdc.gov/coronavirus/2019-ncov/hcp/duration-isolation.html 10
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COVID-19 vaccination of special 

populations
 Any currently authorized COVID-19 vaccine can be administered to persons with 

underlying medical conditions who have no contraindications to vaccination, including:

–

–

–

Immunocompromised persons

People with autoimmune conditions

People with history of Guillain-Barré syndrome, Bell's palsy, dermal filler use

 Clinical trials demonstrate similar safety and efficacy profiles in persons with underlying 

medical conditions, including those that place them at increased risk for severe COVID19, compared to persons without comorbidities

COVID-19 vaccination of persons with underlying medical 

conditions

12 https://www.cdc.gov/coronavirus/2019-ncov/need-extra-precautions/people-with-medical-conditions.html
 Persons with HIV infection, other immunocompromising conditions, or who take 

immunosuppressive medications or therapies might be at increased risk for severe 

COVID-19

 Immunocompromised persons may receive COVID-19 vaccine unless otherwise 

contraindicated

–

–

–

–

All currently authorized vaccines are inactivated vaccines

 Individuals should be counseled about:

Unknown vaccine safety and efficacy profiles in immunocompromised persons

Potential for reduced immune responses

Need to continue to follow current guidance to protect themselves against COVID-19

COVID-19 vaccination of immunocompromised persons

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https://www.cdc.gov/coronavirus/2019-ncov/need-extra-precautions/people-with-medical-conditions.html

https://www.cdc.gov/vaccines/covid-19/info-by-product/clinical-considerations.html#phrecs
 COVID-19 and pregnancy

–

–

–

–

Increased risk of severe illness (ICU admission, mechanical ventilation and death)

Might be an increased risk of adverse pregnancy outcomes

 Currently limited data on safety of COVID-19 vaccines in pregnant people

No concerns demonstrated in animal developmental and reproductive toxicity (DART) studies

Janssen adenovirus vector platform previously used for other clinical development programs 

that included pregnant people, including a large-scale Ebola vaccine trial

 Currently authorized COVID-19 vaccines are all inactivated vaccines

 Clinical trials to evaluate safety and efficacy of COVID-19 vaccines in pregnant people 

planned or underway

COVID-19 vaccination of pregnant people

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https://www.cdc.gov/coronavirus/2019-ncov/need-extra-precautions/pregnancy-breastfeeding.html

https://www.cdc.gov/vaccines/hcp/acip-recs/general-recs/special-situations.html
 Pregnant people may choose to receive COVID-19 vaccine when eligible

–

–

A conversation between the patient and their clinical team may assist with decision, but is 

not required

Conversation should consider: 

• Level of COVID-19 community transmission 

• Personal risk of contracting COVID-19 

• Risks of COVID-19 to patient and fetus 

• Efficacy and side effects of vaccine 

• Limited data about vaccine during pregnancy

COVID-19 vaccination of pregnant people

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Contraindications and precautions 
Contraindications and precautions for COVID-19 vaccines

CONTRAINDICATION TO VACCINATION PRECAUTION TO VACCINATION MAY PROCEED WITH VACCINATION

History of the following:

• Severe allergic reaction (e.g., anaphylaxis) after 

a previous dose or to component of the 

vaccine†

• Immediate allergic reaction* of any severity 

after a previous dose or known (diagnosed) 

allergy to a component of the vaccine†

Actions:

• Do not vaccinate.

• Consider referral to allergist-immunologist.

• Consider other vaccine alternative.†

Among persons without a contraindication, a history 

of:

• Any immediate allergic reaction* to other 

vaccines or injectable therapies‡

Note: persons with a contraindication to mRNA 

COVID-19 vaccines have a precaution to Janssen 

COVID-19 vaccine, and vice versa#

Actions:

• Risk assessment

• Consider referral to allergist-immunologist

• 30-minute observation period if vaccinated

Among persons without a contraindication or 

precaution, a history of:

• Allergy to oral medications (including the oral 

equivalent of an injectable medication)

• History of food, pet, insect, venom, 

environmental, latex, etc., allergies

• Family history of allergies

Actions:

• 30-minute observation period: persons with 

history of anaphylaxis (due to any cause)

• 15-minute observation period: all other 

persons

† See Appendix C for a list of ingredients. Persons with a contraindication to one of the mRNA COVID-19 vaccines should not receive doses of either of the mRNA vaccines (Pfizer-BioNTech or Moderna). 

* Immediate allergic reaction to a vaccine or medication is defined as any hypersensitivity-related signs or symptoms consistent with urticaria, angioedema, respiratory distress (e.g., wheezing, stridor), or anaphylaxis that occur 

within four hours following administration.

‡Includes persons with a reaction to a vaccine or injectable therapy that contains multiple components, one of which is a vaccine component, but in whom it is unknown which component elicited the immediate allergic reaction. #Polyethylene glycol (PEG) is an ingredient in both mRNA COVID-19 vaccines, and polysorbate 80 is an ingredient in Janssen COVID-19 vaccine. PEG and polysorbate are structurally related, and cross-reactive hypersensitivity 

between these compounds may occur. Persons with a contraindication to mRNA COVID-19 vaccines (including due to a known [diagnosed] allergy to PEG) have a precaution to Janssen COVID-19 vaccine. Among persons who 

received one mRNA COVID-19 dose but for whom the second dose is contraindicated, consideration may be given to vaccination with Janssen COVID-19 vaccine (administered at least 28 days after the mRNA COVID-19 dose). 

Persons with a contraindication to Janssen COVID-19 vaccine (including due to a known [diagnosed] allergy to polysorbate) have a precaution to mRNA COVID-19 vaccines. In patients with these precautions, vaccination should be 

undertaken in an appropriate setting under the supervision of a health care provider experienced in the management of severe allergic reactions. Consider referral to allergist-immunologist.
mRNA COVID-19 vaccines Janssen COVID-19 vaccine

• Persons with contraindication to one mRNA vaccine 

should not receive doses of either vaccine (PfizerBioNTech or Moderna)

• Persons with a contraindication to mRNA COVID-19 

vaccines (including due to a known allergy to PEG) 

have a precaution to Janssen COVID-19 vaccine.* 

• In persons who received one mRNA COVID-19 dose 

but are contraindicated to receive the 2nd dose, 

consideration may be given to vaccination with 

Janssen COVID-19 vaccine (at least 28 days after 

mRNA dose).*

• Persons with a contraindication to Janssen COVID-19 

vaccine (including due to a known allergy to 

polysorbate) have a precaution to mRNA COVID-19 

vaccines.* 

Information by vaccine type

*In patients with these precautions, vaccination should be undertaken in an appropriate setting under the supervision of a health care provider experienced in the 

management of severe allergic reactions. Consider referral to allergist-immunologist.

Note: Polyethylene glycol (PEG) is an ingredient in both mRNA COVID-19 vaccines, and polysorbate 80 is an ingredient in Janssen COVID-19 vaccine. PEG and polysorbate are 

structurally related, and cross-reactive hypersensitivity between these compounds may occur.
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Discussion
 Does ACIP agree with the proposed clinical considerations related to vaccination?

 Are there any sections of the clinical considerations that ACIP would like to discuss?

Discussion

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For more information, contact CDC

1-800-CDC-INFO (232-4636)

TTY: 1-888-232-6348 www.cdc.gov

The findings and conclusions in this report are those of the authors and do not necessarily represent the 

official position of the Centers for Disease Control and Prevention.

Thank you