cdc.gov/coronavirus

Updates to COVID-19 vaccine policy: 

Considerations for Future Planning

Sara Oliver, MD, MSPH

ACIP Meeting

April 19, 2023
U.S. COVID-19 vaccine uptake among ages ≥12 years, 

August 2021-January 2023

Source: IZ Data Lake 

0

1,000,000

2,000,000

3,000,000

4,000,000

5,000,000

6,000,000

7,000,000

Primary Series, Ages 12-17 Primary Series, Adults Ages 18-49 Primary Series, Adults Ages 50-64 Primary Series, Adults Ages 65+

Booster, Ages 12-17 Booster, Adults Ages 18-49 Booster, Adults Ages 50-64 Booster Adults Ages 65+

Primary series authorization 

1

st booster authorization 

2

nd booster authorization Bivalent booster authorization 

Doses Administered
Coverage / Age (years) <2 2–4 5–11 12–17 18–24 24–49 50–64 >65

At least 1-dose† 8.6 10.7 39.9 72.1 82.2 85.4 95.0 95.0

Completed primary series 4.5 5.9 32.8 61.7 66.7 72.1 83.8 94.3

Bivalent booster 0.5 0.5 4.6 7.6 7.2 11.8 21.4 42.4

Unvaccinated 91.4 89.3 60.1 28.1 17.8 14.6 —† —†

U.S. COVID-19 Vaccination Coverage (%) of Total Population by 

Age Group — April 13, 2023

†Note: Coverage is capped at 95%

Source: https://covid.cdc.gov/covid-data-tracker/#vaccination-demographics-trends Updated April 13, 2023 3
PI=Prediction Interval, VOC=Variants of Concern, VBM=Variants Being Monitored. https://covid.cdc.gov/covid-data-tracker/#variant-proportions Accessed April 18, 2023

Trends in weighted variant proportion estimates & Nowcast

United States, November 6, 2022–April 15, 2023

Collection date, week ending
Estimated Number of Reported COVID-19 Cases by Variant 

Variant Proportions Scaled by Positive Nucleic Acid Amplification Test (NAAT) Counts

CDC COVID-19 Lab Coordinating Unit Strain Surveillance and Emerging Variant Group. Data sources: https://covid.cdc.gov/covid-data-tracker/#variant-proportions and 

https://covid.cdc.gov/covid-data-tracker/#trends_newtestresultsreported_7daytestingpositive_00

6M

0

4M

2M

Positive tests / Proportion of viral lineages
Weekly population-based rates of COVID-19-associated hospitalizations 

by age group— COVID-NET, March 2020–April 2023

Gray boxes indicate potential reporting delays. Interpretation of trends should be excluded from these weeks. 

https://covid.cdc.gov/covid-data-tracker/#covidnet-hospitalization-network Accessed April 13, 2023

Age Group
Updates to COVID-19 vaccine policy

COVID-19 vaccines: 

Where we are now 

COVID-19 vaccines: 

Where we are going 

Steps toward simple recommendations: 

Single formulation for mRNA COVID-19 vaccines

Single (possibly annual) dose for most individuals

Flexibility for vulnerable populations

Goal: 

Simple

recommendations
Updates to COVID-19 vaccine policy

Steps toward simple recommendations: 

Single formulation for mRNA COVID-19 vaccines

Single (annual?) dose for most individuals

Flexibility for vulnerable populations
Single formulation for mRNA COVID-19 vaccines

▪ Many monovalent COVID-19 vaccine products have already expired, others will 

expire soon 

▪ With recent update, FDA removed authorizations for monovalent mRNA COVID-19 

vaccine products

▪ Harmonization across recommendations with bivalent mRNA COVID-19 vaccines was 

discussed at VRBPAC in January and at ACIP meeting in February 
Single formulation for mRNA COVID-19 vaccines

Benefits and Harms: Summary from previous ACIP meetings

10

▪ Bivalent COVID-19 vaccines are able to induce an immune response when given 

either as a primary series or a booster dose

– Immunogenicity data showed that a BA.1 bivalent vaccine given as a primary series induced antibody 

titers to BA.1 that were 25 times higher than the original monovalent vaccine

– Percentage of patients reporting solicited local or systemic events was similar to or less than percentages 

seen after original vaccine, however this may be a result of the larger percent of seropositive participants 

in the bivalent vaccine group

▪ Limited data to directly compare COVID-19 outcomes after receipt of a monovalent or 

bivalent vaccine 

– Most studies show improvement in neutralizing antibodies for Omicron variants with a bivalent vaccine

– Bivalent vaccines expanded the immune response and provided increased diversity in antibody response

– While unable to directly compare clinical outcomes for monovalent and bivalent vaccines in the U.S., a 

study in the UK found ~10% increase in VE for COVID-19 infections 
Number of mRNA COVID-19 vaccine products

Moderna: 5 products

Pfizer-BioNTech: 6 products 

Previously: 

11 TOTAL Products!

Moderna: 2 products

Pfizer-BioNTech: 3 products 

Moving forward: 

5 Products

Eliminates look-alike vials for 

Moderna and Pfizer-BioNTech
Single formulation for mRNA COVID-19 vaccines

Summary from February ACIP meeting

12

▪ Receiving COVID-19 vaccines continues to be important for prevention of COVID-19 

severe disease, hospitalization, and death

▪ Many children and adolescents remain unvaccinated for COVID-19

▪ COVID-19 vaccine recommendations that are simple to implement may remove some 

barriers to uptake

▪ Harmonizing the formulation for mRNA COVID-19 vaccines could simplify the 

presentations, reduce administration errors, and allow continued access to vaccines

▪ ACIP was supportive of a transition of the mRNA COVID-19 vaccine primary series from 

monovalent (original) to bivalent (original plus Omicron BA.4/5)
Single formulation for mRNA COVID-19 vaccines

Updates from FDA authorizations

13

▪ FDA removed the authorizations for monovalent mRNA COVID-19 vaccines

– BLAs are still in place for monovalent products:

• Comirnaty for ages 12 years and older, with limited doses in circulation 

• Spikevax for ages 18 years and older, but all doses are currently expired

▪ Bivalent mRNA COVID-19 vaccines are now authorized for all indications 

▪ No changes to current language in other COVID-19 vaccine authorizations 

(Novavax or Janssen COVID-19 vaccines)
Single formulation for mRNA COVID-19 vaccines

Implications for CDC recommendations

14

▪ Transition to bivalent COVID-19 vaccines could simplify the presentations, reduce 

administration errors, and allow continued access to vaccines with expiration of 

monovalent products 

Bivalent mRNA COVID-19 vaccines would now be recommended for all indications 
Updates to COVID-19 vaccine policy

Steps toward simple recommendations: 

Single formulation for mRNA COVID-19 vaccines

Single (annual?) dose for most individuals

Flexibility for vulnerable populations
Shifts in vaccine-induced, infection-induced, and hybrid immunity against SARS-CoV2 among people aged ≥16 years — United States, Quarter 2 2021– Quarter 3 2022

No infection or vaccination

Vaccine only-induced 

antibodies

Infection only-induced 

antibodies

Both infection and 

vaccination-induced 

antibodies (hybrid immunity)

Source: CDC (unpublished)
Shifts in vaccine-induced, infection-induced, and hybrid immunity against SARS-CoV2 among people aged ≥16 years by age group — United States, Q2 2021–Q3 2022

No infection or vaccination

Vaccination without previous 

infection

Previous infection without 

vaccination

Both previous infection and 

vaccination (hybrid 

immunity)

16–29 years 30–49 years

50–64 years ≥65 years

Source: CDC (unpublished)
How frequently should people get a COVID-19 vaccine? 

▪ Increases in COVID-19 cases (left) and hospitalizations (right) have occurred:

– During the winter months and/or

– Due to emergence of new immune escape variants

Cases from October 2021-February 2023 highlighted

https://covid.cdc.gov/covid-data-tracker/#trends_weeklycases_select_00 https://covid.cdc.gov/covid-data-tracker/#new-hospital-admissions

Admissions from October 2021 – February 2023 highlighted
Single (possibly annual) COVID-19 vaccine dose

Summary from February ACIP meeting

▪ For most older children, adolescents, and adults, future doses will be additional ‘boost’ 

after prior infection, prior vaccination, or both

▪ Time since last COVID-19 vaccine dose may both increase the incremental benefits of a 

COVID-19 vaccine, and decrease the risk of myocarditis 

▪ Vaccine protection likely declines over time

▪ Winter months and immune escape variants have impacted COVID-19 epidemiology

▪ A simplified, annual recommendation could help reduce vaccine and message fatigue

▪ A plan for a fall booster dose could provide added protection, at a time when many 

would be ~1 year from last dose

– Future epidemiology and SARS-CoV-2 virus evolution could help determine the need for 

continued annual boosters
Single (possibly annual) COVID-19 vaccine dose

Updates from FDA authorizations

20

▪ FDA authorized a single age-appropriate mRNA COVID-19 vaccine dose for most individuals

A single age-appropriate dose of a 

bivalent Moderna COVID-19 vaccine

is authorized for individuals 

ages 6 years and older 

who are unvaccinated, 

or at least 2 months after receipt of any 

monovalent COVID-19 vaccine. 

A single age-appropriate dose of a 

bivalent Pfizer COVID-19 vaccine

is authorized for individuals 

ages 5 years and older

who are unvaccinated,

or at least 2 months after receipt of any 

monovalent COVID-19 vaccine
63

82

89

93

0

10

20

30

40

50

60

70

80

90

100

Mar-Apr May-Jun Jul-Aug Sep-Oct Nov-Dec

Seroprevalence (%)

Month

75

85

92

97

99

0

10

20

30

40

50

60

70

80

90

100

Mar-Apr May-Jun Jul-Aug Sep-Oct Nov-Dec

Seroprevalence (%)

Month

Pediatric infection-induced and combined (vaccine- and infection-induced) 

Seroprevalence from U.S. commercial laboratories — March–December 2022

Source: https://covid.cdc.gov/covid-data-tracker/#pediatric-seroprevalence and unpublished data (CDC) 21

Infection-induced Combined (vaccine- and infection-induced) 
COVID-19 vaccine recommendations in children 5 years and younger

▪ Young children likely still need a ‘prime’ and ‘boost’ to optimize immunity

▪ Young children will continue to age into the vaccine recommendations at 6 months and 

could be SARS-CoV-2 naïve

▪ Additional data forthcoming to evaluate benefits of a multi-dose primary series in all 

children ages 5 years and younger, or if the recommendations could be simplified

– Cost effectiveness analysis

– Additional antibody data in young children 

Coverage / Age (years) <2 years 2–4 years 

At least 1-dose 8.6 10.7

Completed primary series 4.5 5.9

Unvaccinated 91.4 89.3
Single (possibly annual) COVID-19 vaccine dose

Updates from FDA authorizations

23

▪ FDA authorized one, two, or three doses of a bivalent mRNA COVID-19 vaccine for 

children 6 months – 4 or 5 years 

▪ Number of doses depend on age, as well as number and type of prior COVID-19 

vaccine doses received 
Single (possibly annual) COVID-19 vaccine dose

Implications for CDC recommendations

24

▪ A COVID-19 vaccine framework for a single dose could be easy for COVID-19 vaccine 

providers to implement, and for the public to understand 

▪ The current recommendations for a single dose may evolve over time, and could move 

to an annual recommendation

A single bivalent dose would be recommended for everyone ages 6 years and older

– For most people, this is not a change: if someone has not received a bivalent vaccine dose 

yet, they are recommended to receive one, regardless of their previous vaccine history

Children 6 months through 5 years would receive at least two COVID-19 vaccine doses, 

including at least one bivalent COVID-19 vaccine 

– Table and detailed guidance to be published in Interim Clinical Considerations
Updates to COVID-19 vaccine policy

Steps toward simple recommendations: 

Single formulation for mRNA COVID-19 vaccines

Single (annual?) dose for most individuals

Flexibility for vulnerable populations
Weekly population-based rates of COVID-19-associated hospitalizations 

by age group— COVID-NET, March 2020–April 2023

Gray boxes indicate potential reporting delays. Interpretation of trends should be excluded from these weeks. 

https://covid.cdc.gov/covid-data-tracker/#covidnet-hospitalization-network Accessed April 13, 2023

Age Group
Rates of COVID-19 deaths by vaccination status and age, adults ≥65 years —

24 U.S. Jurisdictions, April 2022–January 2023

https://covid.cdc.gov/covid-data-tracker/#rates-by-vaccine-status Accessed April 14, 2023 

Unvaccinated

Vaccinated without updated booster

Vaccinated with updated booster

Unvaccinated

Vaccinated without updated booster

Vaccinated with updated booster

Ages 65–79 years Ages ≥80 years
▪ In a January 2023 survey of adults who had previously received a bivalent booster: 

– 54% said they were awaiting new guidelines for additional doses

– 86% said getting another booster shot was important or a top priority

Additional updated COVID-19 vaccine doses 

Survey data

The survey was conducted January 17 – January 24, 2023, online and by telephone among a nationally representative sample of 1,234 U.S. adults

KFF COVID-19 Vaccine Monitor: January 2023. https://www.kff.org/coronavirus-covid-19/poll-finding/kff-covid-19-vaccine-monitor-january-2023/

Accessed February 7, 2023 28
COVID-19 vaccines and older adults (adults ages ≥65 years) 

Summary from February ACIP meeting

▪ Older adults have higher rates of hospitalization than younger adults

▪ Among older adults, vaccination rates with a bivalent COVID-19 vaccine dose remain low

– It is important for older adults to be up to date on current recommendations, including 

receiving a bivalent booster

▪ ACIP discussed that data were insufficient to support a routine recommendation for 

older adults to receive a COVID-19 vaccine doses every 6 months, but acknowledged this 

population may continue to be more vulnerable to severe COVID-19 and likely needs 

flexibility with COVID-19 vaccine recommendations 
Flexibility for vulnerable populations 

Updates from FDA authorizations

30

▪ For adults ages ≥65 years, a single dose of a bivalent mRNA COVID-19 vaccine (either 

Moderna COVID-19 Vaccine or Pfizer-BioNTech COVID-19 vaccine) may be administered 

at least 4 months following the first dose of a bivalent COVID-19 vaccine
Flexibility for vulnerable populations 

Implications for CDC recommendations

31

▪ The bivalent COVID-19 vaccine continues to provide protection against severe COVID-19 

disease, and rates of hospitalization or death among older adults who have received a 

bivalent booster continue to be low

▪ However, some older adults may benefit from an additional updated COVID-19 vaccine 

dose prior to possible future recommendations for updated vaccines this fall

Adults ages 65 years and older may now choose to receive another 

updated COVID-19 vaccine dose
COVID-19 vaccines and people who are immunocompromised 

Summary from February ACIP meeting

▪ Immunocompromised adults can have less robust immune response to COVID-19 

vaccines

▪ There are no currently authorized prophylactic monoclonal antibody products for 

populations at highest risk of COVID-19 

▪ ACIP discussed that data were insufficient to support a routine recommendation for 

people who are immunocompromised to receive a COVID-19 vaccine doses every 6 

months, but acknowledged this population may continue to be more vulnerable to 

severe COVID-19 and likely needs flexibility with COVID-19 vaccine recommendations 
Flexibility for vulnerable populations 

Updates from FDA authorizations

33

▪ For persons with moderate to severely immunocompromising conditions, a single dose 

of a bivalent mRNA COVID-19 vaccine may be administered at least 2 months following 

the first dose of a bivalent COVID-19 vaccine

▪ Additional age-appropriate bivalent mRNA COVID-19 vaccine doses may be 

administered to immunocompromised persons at the discretion of the healthcare 

provider, taking into consideration the individual’s clinical circumstances
Flexibility for vulnerable populations 

Implications for CDC recommendations 

34

▪ For people who are immunocompromised, additional doses have been recommended 

previously and current updates continue to allow additional protection to a vulnerable 

population 

▪ Updates also allow flexibility to adjust to individual’s specific circumstances, including 

timing of immunosuppression as well as the possible need for re-vaccination after 

particular events (e.g. stem cell transplant) 

– Additional guidance to be published in Interim Clinical Considerations

People who are immunocompromised may now choose to receive another updated 

COVID-19 vaccine dose -andHave the flexibility to receive additional doses based on their clinical circumstances
Updates to COVID-19 vaccine policy

Steps toward simple recommendations: 

Single formulation for mRNA COVID-19 vaccines

Single (possibly annual) dose for most individuals

Flexibility for vulnerable populations

Goal: 

Simple

recommendations
Updates to COVID-19 vaccine policy

Steps toward simple recommendations: 

Single formulation for mRNA COVID-19 vaccines

Single (possibly annual) dose for most individuals

Flexibility for vulnerable populations

Goal: 

Simple

recommendations

Future additional steps may be possible : 

Simplifications for all COVID-19 vaccines

Possible updated vaccines this fall 

Continue to evaluate data-driven ways to 

simplify pediatric program

Flexibility and simple guidance
▪ COVID-19 vaccines continue to be the most effective tool we have to prevent serious 

illness, hospitalization and death from COVID-19 

▪ Simple recommendations are easier to communicate, which may improve uptake

▪ Anticipate that an updated fall vaccine could be available

▪ Based on available data, anticipate benefits of COVID-19 vaccines given this fall 

– Updates to COVID-19 vaccine policy can also acknowledge possible future recommendations 

▪ For most people, the current doses needed remain unchanged: a single bivalent vaccine 

is recommended and there could be an updated vaccine/recommendation this fall

– Flexibility for vulnerable populations

– Young children continue to be recommended for multiple doses to prime/boost immune response, 

and will continue to review additional data

Updates to COVID-19 vaccine policy

Steps toward simple recommendations 
▪ Continue to review data and evaluate COVID-19 vaccine program in context of 

evolving epidemiology 

▪ Early COVID-19 vaccine recommendations made in light of a highly susceptible, 

immune naive population, with limited treatment options

▪ Increases in population-level immunity through both vaccine and infection, 

SARS-CoV-2 virus evolution, availability of anti-viral treatments, and review of COVID19 epidemiology and hospitalization rates can lead to evidence-based updates in 

vaccine policy

▪ Work is ongoing to review additional data, continue efforts for simplification

▪ Work Group supportive of simplified recommendations as well as flexibility for 

vulnerable populations 

Work Group interpretation 

Steps toward simple recommendations
▪ Monica Godfrey

▪ Evelyn Twentyman

▪ Danielle Moulia

▪ Megan Wallace 

▪ Hannah Rosenblum

▪ Lauren Roper

▪ Katherine Fleming-Dutra

▪ Ruth Link-Gelles

▪ Amadea Britton

▪ Sarah Meyer

▪ Julianne Gee

▪ Susan Goldstein

▪ Mary Chamberland

▪ Elisha Hall

▪ Valerie Morelli

▪ JoEllen Wolicki

▪ Heather Scobie

▪ Sierra Scarbrough

▪ Jefferson Jones

▪ Aron Hall

▪ Barbara Mahon

▪ Coronavirus and other Respiratory Viruses Division

▪ National Center for Immunization and Respiratory 

Diseases

Acknowledgments
Question for ACIP

40

▪ What are ACIP's thoughts on simplified recommendations as well as 

flexibility for vulnerable populations?
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