This page undergoes regular review and was last comprehensively reviewed on May 1, 2023. Some sections may reflect more recent updates.
Dosing Schedules
|
Age Group |
Product |
Dose 1 |
Dose 2 |
Dose 3 |
|
6 months – 4 years |
Moderna (bivalent) |
0.25mL/25mcg |
0.25mL/25mcg |
(none) |
|
Pfizer-BioNTech (bivalent) |
0.2mL/3mcg |
0.2mL/3mcg |
0.2mL/3mcg |
|
|
5 years |
Moderna (bivalent) |
0.25mL/25mcg |
0.25mL/25mcg |
(none) |
|
Pfizer-BioNTech (bivalent) |
0.2mL/10mcg |
(none) |
(none) |
|
|
6 – 11 years |
Moderna (bivalent) |
0.25mL/25mcg |
(none) |
(none) |
|
Pfizer-BioNTech (bivalent) |
0.2mL/10mcg |
(none) |
(none) |
|
|
12 – 64 years* |
Moderna (bivalent) |
0.5mL/50mcg |
(none) |
(none) |
|
Pfizer-BioNTech (bivalent) |
0.3mL/30mcg |
(none) |
(none) |
|
|
65 years and up* |
Moderna (bivalent) |
0.5mL/50mcg |
0.5mL/50mcg (optional) |
(none) |
|
Pfizer-BioNTech (bivalent) |
0.3mL/30mcg |
0.3mL/30mcg (optional) |
(none) |
* The monovalent Novavax COVID-19 vaccine remains authorized for the following scenarios:
-
Novavax can be used as a two-dose primary series for individuals 12+ years old. The second of the two doses should be administered 3-8 weeks after the first dose. An 8-week interval between the first and second primary series doses might be optimal for some people ages 6 months–64 years, especially for males 12–39 years old.
-
Novavax can still be used as a booster dose, administered at least 6 months after a primary series, to people 18+ years old, who:
-
Have already completed a COVID-19 vaccine primary series;
-
Have not received any other booster dose(s); AND
-
Are unable or unwilling to receive an mRNA vaccine and would not otherwise receive a booster dose.
|
Age Group |
Vaccination History |
Product |
Dose 1 |
Dose 2 |
|
6 months – 4 years |
1 dose monovalent Moderna, with no bivalent doses |
Moderna (bivalent) |
0.25mL/25mcg |
(none) |
|
2 doses monovalent Moderna, with no bivalent doses |
Moderna (bivalent) |
0.2mL/10mcg |
(none) |
|
|
1 dose monovalent Pfizer-BioNTech, with no bivalent doses |
Pfizer-BioNTech (bivalent) |
0.2mL/3mcg |
0.2mL/3mcg |
|
|
2 or 3 doses monovalent Pfizer-BioNTech, with no bivalent doses |
Pfizer-BioNTech (bivalent) |
0.2mL/3mcg |
(none) |
|
|
At least 2 doses of monovalent Moderna or Pfizer-BioNTech, AND at least 1 dose bivalent Moderna or Pfizer-BioNTech |
(none) |
(none) |
(none) |
|
|
5 years |
1 dose monovalent Moderna, with no bivalent doses |
Moderna (bivalent) |
0.25mL/25mcg |
(none) |
|
(or) Pfizer-BioNTech (bivalent) |
0.2mL/10mcg |
(none) |
||
|
2 doses monovalent Moderna, with no bivalent doses |
Moderna (bivalent) |
0.2mL/10mcg |
(none) |
|
|
(or) Pfizer-BioNTech (bivalent) |
0.2mL/10mcg |
(none) |
||
|
1 or more doses monovalent Pfizer-BioNTech, with no bivalent doses |
Pfizer-BioNTech (bivalent) |
0.2mL/10mcg |
(none) |
|
|
Ever received at least 1 dose bivalent Moderna or Pfizer-BioNTech |
(none) |
(none) |
(none) |
|
|
6 – 11 years |
1 or more doses monovalent Moderna or Pfizer-BioNTech, with no bivalent doses |
Moderna (bivalent) |
0.25mL/25mcg |
(none) |
|
(or) Pfizer-BioNTech (bivalent) |
0.2mL/10mcg |
(none) |
||
|
Ever received at least 1 dose bivalent Moderna or Pfizer-BioNTech |
(none) |
(none) |
(none) |
|
|
12 – 64 years* |
1 or more doses monovalent Moderna or Pfizer-BioNTech, with no bivalent doses |
Moderna (bivalent) |
0.5mL/50mcg |
(none) |
|
(or) Pfizer-BioNTech (bivalent) |
0.3mL/30mcg |
(none) |
||
|
Ever received at least 1 dose bivalent Moderna or Pfizer-BioNTech |
(none) |
(none) |
(none) |
|
|
65+ years* |
1 or more doses monovalent Moderna or Pfizer-BioNTech, with no bivalent doses |
Moderna (bivalent) |
0.5mL/50mcg |
0.5mL/50mcg |
|
(or) Pfizer-BioNTech (bivalent) |
0.3mL/30mcg |
0.3mL/30mcg |
||
|
Received only 1 dose bivalent Moderna or Pfizer-BioNTech |
Moderna (bivalent) |
0.5mL/50mcg
minimum 4-week |
(none) |
|
|
(or) Pfizer-BioNTech (bivalent) |
0.3mL/30mcg |
(none) |
||
|
Received 2 doses of bivalent Moderna or Pfizer-BioNTech |
(none) |
(none) |
(none) |
* The monovalent Novavax COVID-19 vaccine authorized for the following scenarios:
-
Novavax can be used as a two-dose primary series for individuals 12+ years old. The second of the two doses should be administered 3-8 weeks after the first dose. An 8-week interval between the first and second primary series doses might be optimal for some people ages 6 months–64 years, especially for males 12–39 years old.
-
Novavax can still be used as a booster dose, administered at least 6 months after a primary series, to people 18+ years old, who:
-
Have already completed a COVID-19 vaccine primary series;
-
Have not received any other booster dose(s); AND
-
Are unable or unwilling to receive an mRNA vaccine and would not otherwise receive a booster dose.
Dosing Schedule: Immunocompromised, No History of COVID-19 Vaccination
|
Age Group
|
Product
|
Dose 1
|
Dose 2
|
Dose 3
|
Dose 4*
|
|
6 months – 4 years |
Moderna (bivalent) |
0.25mL/25mcg |
0.25mL/25mcg 4-week (28-day) interval |
0.25mL/25mcg minimum 4-week (28-day) interval |
0.25mL/25mcg
minimum 4-week (28-day) interval |
|
Pfizer-BioNTech (bivalent) |
0.2mL/3mcg |
0.2mL/3mcg (21-day) interval |
0.2mL/3mcg
minimum 8-week (56-day) interval |
0.2mL/3mcg
minimum 8-week (56-day) interval (optional) |
|
|
5 years |
Moderna (bivalent) |
0.25mL/25mcg |
0.25mL/25mcg
4-week (28-day) interval |
0.25mL/25mcg
minimum 4-week (28-day) interval |
0.25mL/25mcg
minimum 4-week (28-day) interval (optional) |
|
Pfizer-BioNTech (bivalent) |
0.2mL/10mcg |
0.2mL/10mcg
3-week (21-day) interval |
0.2mL/10mcg
minimum 4-week (28-day) interval |
0.2mL/10mcg
minimum 4-week (28-day) interval (optional) |
|
|
6 – 11 years |
Moderna (bivalent) |
0.25mL/25mcg |
0.25mL/25mcg
4-week (28-day) interval |
0.25mL/25mcg
minimum 4-week (28-day) interval |
0.25mL/25mcg
minimum 4-week (28-day) interval (optional) |
|
Pfizer-BioNTech (bivalent) |
0.2mL/10mcg |
0.2mL/10mcg 3-week (21-day) interval |
0.2mL/10mcg
minimum 4-week (28-day) interval |
0.2mL/10mcg
minimum 4-week (28-day) interval (optional) |
|
|
12 years and up* |
Moderna (bivalent) |
0.5mL/50mcg |
0.5mL/50mcg
4-week (28-day) interval |
0.5mL/50mcg
minimum 4-week (28-day) interval |
0.5mL/50mcg
minimum 4-week (28-day) interval (optional) |
|
Pfizer-BioNTech (bivalent) |
0.3mL/30mcg |
0.3mL/30mcg
3-week (21-day) interval |
0.3mL/30mcg
minimum 4-week (28-day) interval |
0.3mL/30mcg
minimum 4-week (28-day) interval (optional) |
* For moderately to severely immunocompromised individuals, further additional dose(s) may be administered based on clinical judgment of a health care provider and personal preference/circumstances. Any further doses should be administered at least 2 months following the most recent COVID-19 vaccine dose. Where possible, the additional dose(s) should be homologous (should match) with previous doses given.
Dosing Schedule: Immunocompromised, Any History of COVID-19 Vaccination
|
Age Group
|
Vaccination History |
Product |
Dose 1 |
Dose 2 |
Dose 3 |
|
6 months – 4 years |
1 dose monovalent Moderna, with no bivalent doses |
Moderna (bivalent) |
0.25mL/25mcg
4-week (28-day) interval after last monovalent dose |
0.25mL/25mcg
minimum 4-week (28-day) interval |
0.25mL/25mcg
minimum 2-month (60-day) interval (optional)* |
|
2 or more doses monovalent Moderna, with no bivalent doses |
Moderna (bivalent) |
0.2mL/10mcg
minimum 4-week (28-day) interval after last monovalent dose |
0.2mL/10mcg
minimum 2-month (60-day) interval (optional) |
|
|
|
3 doses of monovalent Moderna, with no bivalent doses |
Moderna (bivalent) or |
0.25mL/25mcg
minimum 8-week (56-day) interval after last monovalent dose |
0.25mL/25mcg
minimum 2-month (60-day) interval (optional) |
|
|
|
1 dose monovalent Pfizer-BioNTech, with no bivalent doses |
Pfizer-BioNTech (bivalent) |
0.2mL/3mcg
3-week (21-day) interval after last monovalent dose |
0.2mL/3mcg
minimum 8-week (56-day) interval |
0.2mL/3mcg
minimum 8-week (56-day) interval (optional) |
|
|
2 doses monovalent Pfizer-BioNTech, with no bivalent doses |
Pfizer-BioNTech (bivalent) |
0.2mL/3mcg
minimum 8-week (56-day) interval after last monovalent dose |
0.2mL/3mcg
minimum 2-month (60-day) interval (optional) |
|
|
|
3 doses of Pfizer-BioNTech, with no bivalent doses |
Pfizer (bivalent) |
0.2mL/3mcg
minimum 8-week (56-day) interval after last monovalent dose |
0.2mL/3mcg
minimum 2-month (60-day) interval (optional)
|
|
|
|
Ever received at least 1 bivalent dose of Moderna or Pfizer-BioNTech |
Moderna (bivalent) or |
0.25mL/25mcg
minimum 2-month (60-day) interval after bivalent dose 2 (optional) |
|
|
|
|
Pfizer (bivalent) |
0.2mL/3mcg
minimum 2-month (60-day) interval after bivalent dose 1 (optional) |
|
|
||
|
5 years |
1 dose monovalent Moderna, with no bivalent doses |
Moderna (bivalent) |
0.25mL/25mcg
4-week (28-day) interval after last monovalent dose |
0.25mL/25mcg
minimum 4-week (28-day) interval |
0.25mL/25mcg
at least 2 months after bivalent dose 2 (optional) |
|
2 doses monovalent Moderna, with no bivalent doses |
Moderna (bivalent) |
0.25mL/25mcg
minimum 4-week (28-day) interval after last monovalent dose |
0.25mL/25mcg
minimum 2-month (60-day) interval (optional) |
|
|
|
3 doses monovalent Moderna, with no bivalent doses |
Moderna (bivalent) or |
0.25mL/25mcg
minimum 8-week (56-day) interval after last monovalent dose |
0.25mL/25mcg
minimum 2-month (60-day) interval (optional)
|
|
|
|
Pfizer-BioNTech (bivalent) |
0.2mL/10mcg
minimum 8-week (56-day) interval after last monovalent dose |
0.2mL/10mcg
minimum 2-month (60-day) interval (optional) |
|
||
|
1 dose monovalent Pfizer-BioNTech, with no bivalent doses |
Pfizer-BioNTech (bivalent) |
0.2mL/10mcg
3-week (21-day) interval after last monovalent dose |
0.2mL/10mcg
minimum 4-week (28-day) interval
|
0.2mL/10mcg
minimum 4-week (28-day) interval (optional) |
|
|
2 doses monovalent Pfizer-BioNTech, with no bivalent doses |
Pfizer-BioNTech (bivalent) |
0.2mL/10mcg
4-week (28-day) interval after last monovalent dose |
0.2mL/10mcg
minimum 4-week (28-day) interval (optional) |
|
|
|
3 doses monovalent Pfizer-BioNTech, with no bivalent doses |
Pfizer-BioNTech (bivalent) |
0.2mL/10mcg
minimum 8-week (56-day) interval after last monovalent dose |
0.2mL/10mcg
minimum 4-week (28-day) interval (optional)
|
|
|
|
Ever received at least 1 dose bivalent Moderna or Pfizer-BioNTech |
Moderna (bivalent) or |
0.25mL/25mcg
minimum 2-month (60-day) interval after bivalent dose 1 (optional) |
|
|
|
|
Pfizer-BioNTech (bivalent) |
0.2mL/10mcg
minimum 2-month (60-day) interval after bivalent dose 1 (optional) |
|
|
||
|
6-11 years |
1 dose monovalent Moderna, with no bivalent doses |
Moderna (bivalent) |
0.25mL/25mcg
4-week (28-day) interval after monovalent dose |
0.25mL/25mcg
minimum 4-week (28-day) interval |
0.25mL/25mcg
minimum 2-month (60-day) interval (optional) |
|
2 doses monovalent Moderna, with no bivalent doses |
Moderna (bivalent) |
0.25mL/25mcg
minimum 4-week (28-day) interval after last monovalent dose |
0.25mL/25mcg
minimum 2-month (60-day) interval (optional) |
|
|
|
1 dose monovalent Pfizer-BioNTech, with no bivalent doses |
Pfizer-BioNTech (bivalent) |
0.2mL/10mcg
3-week (21-day) interval after last monovalent dose |
0.2mL/10mcg
minimum 4-week (28-day) interval
|
0.2mL/10mcg
minimum 2-month (60-day) interval (optional) |
|
|
2 doses monovalent Pfizer-BioNTech, with no bivalent doses |
Pfizer-BioNTech (bivalent) |
0.2mL/10mcg
minimum 4-week (28-day) interval after last monovalent dose |
0.2mL/10mcg
minimum 2-month (60-day) interval (optional) |
|
|
|
3 doses monovalent Moderna or 3 doses monovalent Pfizer-BioNTech, with no bivalent doses |
Moderna (bivalent) or |
0.25mL/25mcg
minimum 8-week (56-day) interval after last monovalent dose |
0.25mL/25mcg
minimum 2-month (60-day) interval (optional) |
|
|
|
Pfizer-BioNTech (bivalent) |
0.2mL/10mcg
minimum 8-week (56-day) interval after last monovalent dose |
0.2mL/10mcg
minimum 2-month (60-day) interval (optional) |
|
||
|
Ever received at least 1 dose bivalent Moderna or Pfizer-BioNTech |
Moderna (bivalent) or |
0.25mL/25mcg
minimum 2-month (60-day) interval after bivalent dose 1 (optional) |
|
|
|
|
Pfizer-BioNTech (bivalent) |
0.2mL/10mcg
minimum 2-month (60-day) interval after bivalent dose 1 (optional) |
|
|
||
|
12 years and up** |
1 dose monovalent Moderna, with no bivalent doses |
Moderna (bivalent) |
0.5mL/50mcg
4-week (28-day) interval after last monovalent dose |
0.5mL/50mcg
minimum 4-week (28-day) interval
|
0.5mL/50mcg
minimum 2-month (60-day) interval (optional) |
|
2 doses monovalent Moderna, with no bivalent doses |
Moderna (bivalent) |
0.5mL/50mcg
minimum 4-week (28-day) interval after last monovalent dose |
0.5mL/50mcg
minimum 2-month (60-day) interval (optional) |
|
|
|
1 dose monovalent Pfizer-BioNTech, with no bivalent doses |
Pfizer-BioNTech (bivalent) |
0.3mL/30mcg
3-week (21-day) interval after monovalent dose |
0.3mL/30mcg
minimum 4-week (28-day) interval
|
0.3mL/30mcg
minimum 2-month (60-day) interval (optional) |
|
|
2 doses monovalent Pfizer-BioNTech, with no bivalent doses |
Pfizer-BioNTech (bivalent) |
0.3mL/30mcg
minimum 4-week (28-day) interval after last monovalent dose |
0.3mL/30mcg
minimum 2-month (60-day) interval (optional) |
|
|
|
At least 3 doses of monovalent Moderna or Pfizer-BioNTech, with no bivalent doses |
Moderna (bivalent) or |
0.5mL/50mcg
minimum 8-week (56-day) interval after last monovalent dose |
0.5mL/50mcg
minimum 2-month (60-day) interval (optional) |
|
|
|
Pfizer-BioNTech (bivalent) |
0.3mL/30mcg
minimum 8-week (56-day) interval after last monovalent dose |
0.3mL/30mcg
minimum 2-month (60-day) interval (optional) |
|
||
|
Ever received at least 1 dose bivalent Moderna or Pfizer-BioNTech |
Moderna (bivalent) or |
0.5mL/50mcg
minimum 2-month (60-day) interval after bivalent dose 2 (optional) |
|
|
|
|
Pfizer-BioNTech (bivalent) |
0.3mL/30mcg
minimum 2-month (60-day) interval after bivalent dose 2 (optional) |
|
|
* For moderately to severely immunocompromised individuals, further additional dose(s) may be administered based on clinical judgment of a health care provider and personal preference/circumstances. Any further doses should be administered at least 2 months following the most recent COVID-19 vaccine dose. Where possible, the additional dose(s) should be homologous (should match) with previous doses given.
** The monovalent Novavax COVID-19 vaccine remains authorized for the following scenarios:
· Novavax can be used as a two-dose primary series for individuals 12+ years old. The second of the two doses should be administered 3-8 weeks after the first dose. An 8-week interval between the first and second primary series doses might be optimal for some people ages 6 months–64 years, especially for males 12–39 years old.
· People aged 12 years and up who previously received one or more doses of Novavax COVID-19 vaccine are recommended to receive one bivalent mRNA vaccine dose at least 8 weeks after their last monovalent dose.
· Otherwise, Novavax can still be used as a booster dose, administered at least 6 months after a primary series, to people 18+ years old, who:
o Have already completed a COVID-19 vaccine primary series,
o Have not received any other booster dose(s); AND
o Are unable or unwilling to receive an mRNA vaccine and would not otherwise receive a booster dose.
Mixed Products
In the U.S., CDC currently recommends completing a primary series of a two-dose vaccine (or three doses for certain immunocompromised patients) with the same product, whenever possible. For booster vaccination, FDA has authorized the use of heterologous (or “mix and match”) booster doses for currently available mRNA, recombinant subunit and viral vector COVID-19 vaccines. Interim CDC guidance addresses clinical considerations related to heterologous booster doses, including patient benefit-risk considerations when selecting which booster dose to receive.
Evidence
Primary series
There have been few studies evaluating a mixed product primary series with the vaccines currently available in the U.S. The largest such study, the Com-COV2 trial, was conducted in the U.K. and compared the safety and immunogenicity of two doses of the Pfizer-BioNTech and Oxford-AstraZeneca vaccines with heterologous schedules containing one dose of either followed by one dose of either the Moderna or Novavax COVID-19 vaccine (Stuart, December 2021). The safety and immunogenicity of a vaccine series containing two doses of the Pfizer-BioNTech vaccine were similar to a vaccine series containing one dose of Pfizer-BioNTech followed by one dose of Moderna. Antibody and cellular response were slightly higher in the mixed schedule group, which may be attributable to the higher antigen content in the Moderna vaccine rather than any benefit of a mixed schedule per se.
The Com-COV2 trial and other studies outside the U.S. have also evaluated mixed schedules containing one dose of an mRNA vaccine and one dose of the Oxford-AstraZeneca vaccine (which is based on a similar technology to the Johnson & Johnson/Janssen COVID-19 vaccine), though the time between the first and second dose of vaccine in these studies has been variable. Most of these studies have concluded that a two-dose schedule that includes both vaccines, in either order, generates a robust antibody and cellular response, compared with a single dose of either vaccine. Furthermore, in the studies where a heterologous and homologous (i.e., containing two doses of the same vaccine product) schedule were directly compared, the safety profile and immune responses with both schedules appeared to be similar (Borobia, June 2021; Shaw, May 2021; Liu, August 2021; Ostadgavahi, May 2021; Hillus, November 2021; Schmidt, September 2021; Tenbusch, July 2021; Dimeglio, August 2021). In some studies, a heterologous schedule containing one Oxford-AstraZeneca and one mRNA COVID-19 vaccine dose elicited a more robust cellular response and higher neutralizing antibody titers against SARS-CoV-2 variants than a homologous schedule containing two doses of the Oxford-AstraZeneca vaccine (Barros-Martins, July 2021; Kaku, February 2022).
Boosters
Some studies suggest that heterologous boosters may be superior to homologous boosters. Per CDC guidance, mRNA COVID-19 boosters are preferred over the Johnson & Johnson/Janssen COVID-19 vaccine. Data to support this recommendation come from studies on immunogenicity (Atmar, January 2022; Munro, December 2021; Sablerolles, January 2022) and clinical effectiveness (Mayr, February 2022; Hui Xuan Tan, February 2022).
Timing/Intervals
The interval between doses of two-dose COVID-19 vaccines may impact their immunogenicity and clinical effectiveness. However, to date there are limited data for this strategy; therefore, alternative schedules are not currently recommended.
Key primary studies that have evaluated the effect of alternate COVID-19 vaccine schedules are summarized below.
mRNA vaccine interval
There is accumulating evidence that a longer interval between the two doses of mRNA COVID-19 vaccines may confer improved immunogenicity and potentially even clinical effectiveness. Studies in the U.K. and Canada have demonstrated that a longer time period (ranging from 6-16 weeks depending on the study) between the two doses of both the Pfizer-BioNTech and Moderna COVID-19 vaccines is associated with increased antibody and cellular responses (Parry, August 2021; Grunau, November 2021; Grunau, December 2021; Payne, November 2021). A separate analysis in the U.K. of 750 adults aged 50-79 years confirmed these findings and further demonstrated that an interval of >45 days between dose one and two of the Pfizer-BioNTech COVID-19 vaccine was associated with improved vaccine effectiveness (over a follow-up period that preceded emergence of the Delta variant) against SARS-CoV-2 infection (Amirthalingam, December 2021).
Viral vector vaccine interval
In an exploratory analysis of a Phase 3 randomized controlled trial of the Oxford-AstraZeneca COVID-19 vaccine, investigators evaluated the impact of variable timing of the second dose of vaccine. In this analysis, vaccine efficacy against primary symptomatic COVID-19 (starting 14 days after the second dose) was higher with longer dose intervals. Vaccine efficacy was 55.1% (95% CI, 33.0-69.9) when the interval between the two doses was less than 6 weeks and 81.3% (60.3-91.2) when the interval was more than 12 weeks (Voysey, February 2021).
Coadministration (with non-COVID-19 vaccines)
Per CDC recommendations, COVID-19 vaccines can be administered without regard to timing of other vaccines. Of note, the effect of coadministration or closely spaced administration of COVID-19 and non-COVID-19 vaccines on immunogenicity and reactogenicity has not yet been well characterized.
Individuals receiving an orthopoxvirus vaccine (JYNNEOS or ACAM2000) may consider waiting 4 weeks before receiving a COVID-19 vaccine due to a risk of myocarditis/pericarditis associated with orthopoxvirus vaccines. If an orthopoxvirus vaccine is being administered in the context of prophylaxis, administration should not be delayed because of recent receipt of a COVID-19 vaccine.