What are the guidelines for administering the Pfizer (Comirnaty) vaccine for COVID-19?

Pfizer COVID-19 Vaccine Administration Guidelines

For the 2024-2025 COVID-19 season, all individuals aged ≥6 months should receive at least one dose of the updated Pfizer-BioNTech COVID-19 vaccine (monovalent KP.2-strain), regardless of prior vaccination history. 1, 2

General Dosing Recommendations

For Persons Without Moderate or Severe Immunocompromise:

• Ages 5 years and older who were previously vaccinated: One dose of 2024-2025 Pfizer-BioNTech COVID-19 vaccine, administered at least 8 weeks after the last COVID-19 vaccine dose 1
• Ages 12 years and older who are unvaccinated: One dose of 2024-2025 Pfizer-BioNTech COVID-19 vaccine 1
• Ages 6 months to 4 years who are unvaccinated: Three-dose primary series of Pfizer-BioNTech vaccine with 3-8 weeks between doses 1 and 2, and ≥8 weeks between doses 2 and 3 1
• Ages 6 months to 4 years with prior Pfizer vaccination:
  • If received 1 dose: Need 2 more doses of 2024-2025 vaccine (3-8 weeks between doses) 1
  • If received 2 doses: Need 1 more dose of 2024-2025 vaccine (≥8 weeks after dose 2) 1
  • If received ≥3 doses: Need 1 dose of 2024-2025 vaccine (≥8 weeks after last dose) 1

For Persons With Moderate or Severe Immunocompromise:

• Ages 6 months to 11 years who are unvaccinated: Three-dose primary series of 2024-2025 Pfizer-BioNTech vaccine from the same manufacturer 1
• Ages ≥12 years who are unvaccinated: Three-dose primary series of 2024-2025 Pfizer-BioNTech vaccine from the same manufacturer 1
• Previously vaccinated with completed initial series: At least one dose of 2024-2025 COVID-19 vaccine, with possibility of an additional dose at least 2 months after the last recommended dose 1

Special Populations

• Multiple sclerosis patients: Vaccination is recommended, but should be administered 4-6 weeks before starting ocrelizumab treatment or 4-6 months after ending treatment 1
• Patients on immunosuppressive therapies:
  • For those receiving immune-reconstitution therapies (including rituximab and ocrelizumab), vaccination should be delayed until 6 months after the last treatment dose 1
  • For those on high-dose or long-term corticosteroids, vaccination is recommended 4-6 weeks after cessation of treatment 1

Safety Profile

• The Pfizer-BioNTech COVID-19 vaccine has demonstrated a favorable safety profile across age groups 3, 4
• Most common side effects are mild to moderate and include:
  • Injection site pain (79-86% of recipients) 3
  • Fatigue (60-66%) 3
  • Headache (55-65%) 3
• Reactions are typically transient and occur most frequently the day after vaccination 4
• Serious adverse events are rare 4, 5

Efficacy

• The Pfizer-BioNTech vaccine has demonstrated high efficacy against COVID-19:
  • In adolescents 12-15 years: 100% efficacy (95% CI, 75.3-100) 3
  • For booster (third) doses: 95.3% relative vaccine efficacy (95% CI, 89.5-98.3) compared to two doses 5
  • Through 6 months after primary series: 91.3% efficacy (95% CI, 89.0-93.2) 6
  • Against severe disease: 96.7% efficacy (95% CI, 80.3-99.9) 6

Important Considerations

• The 2024-2025 COVID-19 vaccines are updated monovalent vaccines specifically targeting current circulating variants (Omicron JN.1-line, including JN.1 and KP.2) 2
• The choice of vaccine manufacturer does not need to match prior vaccinations 2
• For individuals who recently had SARS-CoV-2 infection, consider delaying vaccination by 3 months after symptom onset or positive test 2
• Before vaccination, providers should provide the appropriate EUA Fact Sheet or manufacturer's package insert and counsel recipients about expected reactogenicity 1
• Adverse events should be reported to the Vaccine Adverse Event Reporting System (VAERS) 1

Common Pitfalls to Avoid

• Not waiting the appropriate interval between doses (minimum 8 weeks after previous dose for most individuals) 1
• Failing to adjust vaccination timing for patients on immunosuppressive therapies 1
• Not recognizing that children 6 months to 4 years require a multi-dose primary series, unlike older age groups 1
• Overlooking the need for additional doses in moderately or severely immunocompromised individuals 1