Pfizer-BioNTech COVID-19 Vaccine

by David Freedman last updated 2023-06-01 16:19:45.206242-04:00 © Antimicrobial Therapy, Inc.
Comirnaty, mRNA BNT162b2, bivalent, omicron, BA.4/5

Introduction

  • CDC latest recommendations (May 1, 2023) are that monovalent (original) mRNA vaccines are no longer recommended in the US.
  • Almost the entire US population already has antibody against SARS-CoV-2 from previous infection or vaccination.
    • Unvaccinated individuals need only to receive a single dose of a bivalent vaccine, rather than multiple doses of the original monovalent mRNA vaccines. 
  • A single additional bivalent vaccine dose for adults >65 years and 1 or more additional doses for people who are immunocompromised are now recommended.
    • The updated FDA EUA states that most immunocompromised persons who have received a bivalent COVID-19 vaccine may receive a single additional dose of a bivalent vaccine >2 months following a dose of a bivalent vaccine, and additional doses may be administered at the discretion of, and at intervals determined by, their healthcare provider.
  • All persons >6 yrs should receive a bivalent mRNA vaccine, regardless of previous completion of a monovalent primary series.
  • Persons  >6 yrs who have already received a bivalent mRNA vaccine need no further doses unless they are >65 years or immunocompromised.
  • See COVID-19, Vaccines.

Vaccine

  • Type:  Lipid nanoparticle (LNP) encapsulated mRNA
  • Pfizer COVID-19 Vaccine, Monovalent (original strain)(Comirnaty, mRNA BNT162b2)
  • Pfizer COVID-19 Vaccine, Bivalent (original and Omicron BA.4/BA.5). Not branded at present.

Dose and Schedule (normal host)

  • Available Pfizer vaccine vials in the US. Choice of vials (differential color-coding) should be under the supervision of a pharmacist.
  • In general, persons should receive the age-appropriate vaccine product and dosage based on their age on the day of vaccination in accordance with the recommended intervals for that age group; certain 4 and 5 yr olds present exceptions.
  • Normal host = not moderately or severely immunocompromised.
  • Abbreviated, non-comprehensive CDC infographic

Age >12 yrs

COVID-19 vaccination history Bivalent vaccine #of bivalent doses indicated* Dosage (mL/ug) Interval between doses
Unvaccinated Pfizer 1 0.3 mL/30 ug NA
1 or more doses monovalent mRNA (no doses bivalent mRNA) Pfizer 1 0.3 mL/30 ug >8 wks after last monovalent dose
Ever received 1 dose bivalent mRNA (regardless of monovalent vaccine history) NA; previously received 1 bivalent vaccine dose NA NA NA
  • *Additional bivalent dose. Persons 65 years and older have the option to receive 1 additional bivalent mRNA vaccine dose >4 months after the first dose of a bivalent mRNA vaccine. If Pfizer is used, administer 0.3 mL/30 ug

Age 6 months–4 years

COVID-19 vaccination history Bivalent vaccine # of bivalent doses indicated Dosage (mL/ug) Interval between doses
Unvaccinated Pfizer 3 0.2 mL/3 ug Dose 1 and Dose 2: 3-8 wks; Dose 2 and Dose 3: >8 wks
1 dose monovalent Pfizer Pfizer 2 0.2 mL/3 ug Dose 1: 3–8 wks after monovalent dose
Dose 1 and Dose 2: >8 wks
2 doses monovalent Pfizer Pfizer 1 0.2 mL/3 ug >8 wks after last monovalent dose
3 doses monovalent Pfizer Pfizer 1 0.2 mL/3 ug >8 wks after last monovalent dose
2 doses monovalent Pfizer and 1 dose bivalent Pfizer NA; previously received 1 bivalent vaccine dose NA NA NA

Age 5 years

COVID-19 vaccination history Bivalent vaccine # of bivalent doses indicated Dosage (mL/ug) Interval between doses
Unvaccinated Pfizer 1 0.2 mL/10 ug NA
1 dose monovalent Moderna Pfizer 1 0.2 mL/10 ug >8 wks after monovalent dose
2 doses monovalent Moderna Pfizer 1 0.2 mL/10 ug >8 wks after monovalent dose
2 doses monovalent Moderna and 1 dose bivalent mRNA NA; previously received 1 bivalent vaccine dose NA NA NA
1 or more doses monovalent Pfizer Pfizer 1 0.2 mL/10 ug >8 wks after monovalent dose
2 doses monovalent Pfizer and 1 dose bivalent Pfizer NA; previously received 1 bivalent vaccine dose NA NA NA
Ever received 1 dose bivalent Pfizer (regardless of monovalent vaccine history) NA; previously received 1 bivalent vaccine dose NA NA NA

Age 6–11 years

COVID-19 vaccination history Bivalent vaccine # of bivalent doses indicated Dosage (mL/ug) Interval between doses
Unvaccinated Pfizer 1 0.2 mL/10 ug NA
1 or more doses monovalent mRNA (no doses bivalent mRNA) Pfizer 1 0.2 mL/10 ug >8 wks after last monovalent dose
2 or more doses monovalent mRNA and 1 dose bivalent mRNA NA; previously received 1 bivalent vaccine dose NA NA NA
Ever received 1 dose bivalent mRNA (regardless of monovalent vaccine history) NA; previously received 1 bivalent vaccine dose NA NA NA

Toxicities

Contraindications

  • Anaphylaxis or immediate allergic reaction (within 4h) to a previous dose of an mRNA vaccine or separately to a vaccine constituent including polyethylene glycol (PEG) or polysorbate.
  • Do not vaccinate with any mRNA vaccine
  • History of a known diagnosed allergy to a vaccine component

Precautions

  • Immediate allergic reaction (within 4h) to any other vaccine or injectable therapy not related to a component of mRNA-COVID-19 vaccines or polysorbate.
  • Persons with a reaction to a vaccine or injectable therapy that contains PEG.
  • History of MIS-C or MIS-A.
  • History of myocarditis or pericarditis after a dose of an mRNA or Novavax COVID-19 vaccine, is a precaution to future doses of any COVID-19 vaccine but wait until episode is completely resolved.
  • Myocarditis or pericarditis unrelated to mRNA or Novavax COVID-19 vaccination; administer any age-appropriate vaccine after the episode has resolved.
  • Allergy-related contraindication to one type of COVID-19 vaccine is a precaution to the other types of COVID-19 vaccines.
  • Defer vaccination until resolution of a moderate or severe acute illness, with or without fever.

Not Contraindications

  • Food (including egg and gelatin), pet, insect, venom, environmental, latex, oral medications; any other history of anaphylaxis not related to vaccine or injectables.
  • History of GBS in proximity to another vaccine.

Adverse Effects

  • Safety similar whether monovalent or bivalent vaccine is used as a 4th dose (2nd booster).
  • Myocarditis: 131 myocarditis cases reported to VAERS after 123 million mRNA booster vaccinations.
    • Risk primarily in adolescent and young adult males
    • No increase in children age 5–11 yrs following 1st booster
    • Rates are lower following 1st booster dose vs. dose 2 of primary series (and lower following dose 1 vs. dose 2 of primary series)
    • An 8-week interval between the first and second primary series doses of Moderna, Novavax, and Pfizer COVID-19 vaccines may be optimal to reduce myocarditis.
  • No safety signals for ischemic stroke with mRNA vaccines with primary doses or monovalent boosters in US or any other country.
    • One small cluster of ischemic stroke after a bivalent booster in persons >65 at a single reporting site in 1 of several US CDC and Pfizer surveillance networks needs further investigation. 
    • Possible association with concomitant adjuvanted influenza vaccine needs study prior to 2023-24 flu season.

Pregnancy

  • Vaccinate according to standard recommendations if pregnant, breastfeeding, attempting or contemplating conception.
  • Pregnant and recently pregnant persons at increased risk for severe illness and the fetus is at increased risk.

  • Benefits outweighs risks of vaccination.
  • Antibodies are transferred to the newborn.
  • No contraindications to breastfeeding.

Severely or Moderately Immunocompromised / HIV

Age >12 yrs

COVID-19 vaccination history Bivalent vaccine # Bivalent doses indicated* Dosage (mL/ug) Interval between doses
Unvaccinated Pfizer BioNTech or Moderna 3 Pfizer: 0.3 mL/30 ug or
Moderna: 0.5 mL/50 ug
Dose 1 & Dose 2: 3 wks
Dose 2 & dose 3: >4 wks
3 doses monovalent Moderna Pfizer BioNTech 1 0.3 mL/30 ug >8 wks after last monovalent dose
3 doses monovalent Moderna and 1 dose bivalent mRNA - See footnote - -
1 dose monovalent Pfizer Pfizer BioNTech or Moderna 2 Pfizer: 0.3 mL/30 ug or
Moderna: 0.5 mL/50 ug
Dose 1: 3 wks after monovalent dose
Dose 1 & Dose 2: >4 wks
2 doses monovalent Pfizer Pfizer BioNTech or Moderna 1 Pfizer: 0.3 mL/30 ug or
Moderna: 0.5 mL/50 ug
>4 wks after last monovalent dose
3 doses monovalent Pfizer Pfizer BioNTech 1 0.3 mL/30 ug >8 wks after last monovalent dose
3 doses monovalent Pfizer and 1 dose bivalent mRNA - See footnote - -
  • Footnote: *Immunocompromised persons ages >12 yrs  have the option to receive 1 additional dose of Moderna  (0.5 mL/50 ug); or Pfizer (0.3 mL/30 ug ) >2 months following the last recommended bivalent dose. Further additional dose(s) may be administered, informed by clinical judgement and personal preference and circumstances > 2 months after the last vaccine dose.

Age 6 mos–4 yrs

COVID-19 vaccination history Bivalent vaccine # Bivalent doses indicated* Dosage (mL/ug) Interval between doses
Unvaccinated Pfizer 3 0.2 mL/3 ug Dose 1 & Dose 2: 3 wks
Dose 2 & Dose 3: >8 wks
1 dose monovalent Pfizer Pfizer 2 0.2 mL/3 ug Dose 1: 3 wks after monovalent dose
Dose 1 & Dose 2: >8 wks
2 or 3 doses monovalent Pfizer Pfizer 1 0.2 mL/3 ug >8 wks after last monovalent dose
2 or 3 doses monovalent Pfizer and 1 dose bivalent Pfizer - See footnote - -
  • Footnotes
    • *Immunocompromised ages 6 months–4 years  have the option to receive 1 additional dose of a homologous bivalent mRNA vaccine >2 months following the last recommended bivalent mRNA dose. Further additional homologous bivalent dose(s) may be administered, informed by clinical judgement and personal preference and circumstances. Any further additional doses should be administered >2 months after the last dose. For Pfizer, administer 0.2 mL/3 ug.
    • FDA EUA requires that children who transition from age 4 years to 5 years during the Pfizer vaccination series receive the 0.2 mL/3 ug dosage for all doses.

Age 5 yrs

COVID-19 vaccination history Bivalent vaccine # Bivalent doses indicated* Dosage (mL/ug) Interval between doses
Unvaccinated Pfizer BioNTech 3 0.2 mL/10 ug Dose 1 & Dose 2: 3 wks
Dose 2 & Dose 3: >4 wks
3 doses monovalent Moderna Pfizer BioNTech 1 0.2 mL/10 ug >8 wks after last monovalent dose
3 doses monovalent Moderna and 1 dose bivalent mRNA - See footnote - -
1 dose monovalent Pfizer Pfizer BioNTech 2 0.2 mL/10 ug Dose 1: 3 wks after monovalent dose
Dose 1 & Dose 2: >4 wks
2 doses monovalent Pfizer Pfizer BioNTech 1 0.2 mL/10 ug >4 wks after last monovalent dose
3 doses monovalent Pfizer Pfizer BioNTech 1 0.2 mL/10 ug >8 wks after last monovalent dose
3 doses monovalent Pfizer and 1 dose bivalent Pfizer - See footnote - -
  • Footnotes
    • *Immunocompromised persons age 5 years have the option to receive 1 additional dose of a bivalent mRNA vaccine >2 months following the last recommended bivalent mRNA dose. Further additional bivalent dose(s) may be administered, informed by the clinical judgement and personal preference and circumstances. Any further additional doses should be administered >2 months after the last dose. Persons in this age group who previously received a dose(s) of Pfizer vaccine are authorized to receive only Pfizer vaccine. Recipients who previously received Moderna vaccine are authorized to receive either bivalent mRNA vaccine.
    • If Moderna is used, 0.2mL/10 ug is recommended; 0.25/ml 25ug is also authorized.
    • If Pfizer is used, administer 0.2 mL/10 ug (orange cap and label with an orange border).

Age 6-11 yrs

COVID-19 vaccination status Bivalent vaccine # Bivalent doses indicated* Dosage (mL/ug) Interval between doses
Unvaccinated Pfizer BioNTech 3 0.2 mL/10 ug Dose 1 & Dose 2: 3 wks
Dose 2 & Dose 3: >4 wks
3 doses monovalent Moderna Pfizer BioNTech 1 0.2 mL/10 ug >8 wks after last monovalent dose
3 doses monovalent Moderna and 1 dose bivalent mRNA - See footnote - -
1 dose monovalent Pfizer Pfizer BioNTech 2 0.2 mL/10 ug Dose 1: 3 wks after monovalent dose
Dose 1 & Dose 2: >4 wks
2 doses monovalent Pfizer Pfizer BioNTech 1 0.2 mL/10 ug >4 wks after last monovalent dose
3 doses monovalent Pfizer Pfizer BioNTech 1 0.2 mL/10 ug >8 wks after last monovalent dose
3 doses monovalent Pfizer and 1 dose bivalent mRNA -
See footnote - -
  • Footnotes
    • *Immunocompromised persons ages 6–11 years  have the option to receive 1 additional dose of Moderna (0.25mL/25 ug) or Pfizer vaccine (0.2 mL/10 ug)  >2 months following the last recommended bivalent dose. Further additional dose(s) may be administered, informed by the clinical judgement and personal preference and circumstances. Any further additional doses should be administered >2 months after the last COVID-19 vaccine dose.
    • Moderna COVID-19 Vaccine (0.25 mL/25 ug) is also authorized in this age group with this vaccination history.
  • If possible, COVID-19 vaccines should be administered >2 wks before initiation or resumption of immunosuppressive therapies.
  • Persons with HIV not at higher risk of severe disease after completing vaccination.
    • Severe disease risk higher if CD4<350 even with vaccination;  ensure up to date with bivalent boosting.
  • NCCN recommends against Novavax in active cancer patients unless no choice.
  • Self-attestation to moderately or severely immunocompromised status is acceptable.
  • New immunocompromise after a 2-dose primary series, no additional primary doses;  immunocompromised schedule for the booster dose.
  • Revaccinate HCT or CAR-T-cell therapy recipients with an mRNA vaccine or Novavax >3 mos after HCT or CAR-T-cell therapy .
  • Consider revaccination if 1 or more doses of vaccine (primary series and bivalent booster doses) received during short-course treatment with B-cell-depleting therapies (e.g., rituximab, ocrelizumab)  begining at about 6 mos after completion of therapy.

  • Administration of vaccines should not be delayed in patients on ongoing immunosuppressives.
  • Administer vaccine doses approximately 4 wks before the next scheduled therapy for patients on ongoing B-cell-depleting therapies.
  • Tixagevimab/cilgavimab (Evusheld) no longer recommended as prophylaxis.
  • On a case-by-case basis, providers may administer Moderna, Novavax, and Pfizer vaccines outside of the FDA and CDC dosing intervals using a risk-benefit approach together with clinical experience and judgement.

Serologic Testing

  • Antibody testing is not recommended to assess for immunity following COVID-19 vaccination or to assess the need for vaccination in an unvaccinated person.
  • No correlates of protection are available and assays vary widely.
  • +ve IgG only minimally reassuring, -ve IgG unhelpful in patients whose ability to mount a B-cell response is uncertain.
  • If antibody testing is done, vaccination should be completed as recommended regardless of the antibody test result.
  • Prior receipt of a COVID-19 vaccine will not affect the results of SARS-CoV-2 viral tests (nucleic acid amplification or antigen tests).

Comments

  • Consider 15 minute observation period post-administration especially for adolescents.
  • Consider 30 minute observation period post-administration if:
    • Allergy related contraindication to another COVID vaccine
    • Non-severe allergic reaction (within 4 hrs) to any previous COVID vaccine
    • Anaphylaxis after non-COVID-19 vaccines or injectable therapies
  • Age-appropriate vaccine product and dosage is based on age on the day of vaccination. A move from a younger age group to an older age group during the primary series, requires the vaccine product and dosage for the older age group.
  • Vaccines are not recommended for outbreak management or for post-exposure prophylaxis
  • mRNA vaccines do not have a risk of modifying the vaccine recipient’s genetic makeup as mRNA does not enter cell nucleus where host DNA is located.