Summary

What is already known about this topic?

In September 2023, the Advisory Committee on Immunization Practices (ACIP) recommended updated (20232024 Formula) COVID-19 vaccination for all persons aged 6 months.

What is added by this report?

On February 28, 2024, ACIP recommended that all persons aged 65 years receive 1 additional dose of any updated (20232024 Formula) COVID-19 vaccine (i.e., Moderna, Novavax, or Pfizer-BioNTech).

What are the implications for public health practice?

Adults aged 65 years should receive an additional dose of the updated (20232024 Formula) COVID-19 vaccine to enhance their immunity and decrease the risk for severe COVID-19associated illness.

COVID-19 remains an important public health threat, despite overall decreases in COVID-19related severe disease since the start of the COVID-19 pandemic. COVID-19associated hospitalization rates remain higher among adults aged 65 years relative to rates in younger adults, adolescents, and children; during October 2023January 2024, 67% of all COVID-19associated hospitalizations were among persons aged 65 years. On September 12, 2023, CDCs Advisory Committee on Immunization Practices (ACIP) recommended updated (20232024 Formula) COVID-19 vaccination with a monovalent XBB.1.5-derived vaccine for all persons aged 6 months to protect against severe COVID-19associated illness and death. Because SARS-CoV-2 continues to circulate throughout the year, and because of the increased risk for COVID-19related severe illness in persons aged 65 years, the protection afforded by updated vaccines against JN.1 and other currently circulating variants, and the expected waning of vaccine-conferred protection against disease, on February 28, 2024, ACIP recommended all persons aged 65 years receive 1 additional dose of the updated (20232024 Formula) COVID-19 vaccine. Implementation of these recommendations is expected to enhance immunity that might have waned and decrease the risk for severe COVID-19associated outcomes, including death, among persons aged 65 years.

Since June 2020, CDCs Advisory Committee on Immunization Practices (ACIP) has convened 39 public meetings to review data and consider recommendations related to the use of COVID-19 vaccines (1). On September 12, 2023, ACIP recommended that all persons aged 6 months receive updated (20232024 Formula) monovalent, XBB.1.5 component (updated) COVID-19 vaccination to protect against severe COVID-19associated illness and death (2).

As of February 3, 2024, approximately 6.7 million COVID-19associated hospitalizations and 1.1 million COVID-19associated deaths had occurred in the United States (3). Although the overall risk for COVID-19associated hospitalization and death has decreased, severe illness related to COVID-19 continues to be a public health problem, especially among older adults. COVID-19associated hospitalization rates remain higher among adults aged 65 years relative to rates among younger adults, adolescents, and children. During October 2023January 2024, 67% of all COVID-19associated hospitalizations were among persons aged 65 years (4). Further, COVID-19 death rates during January 1, 2023January 31, 2024, were highest among adults aged 75 years, followed by adults aged 6574 years (5,6). Whereas approximately 98%99% of the U.S. population has measurable antibody titers against SARS-CoV-2 from infection, vaccination, or both (hybrid immunity), adults aged 65 years are less likely to have immunity resulting from infection (including immunity from infection only or hybrid immunity), compared with adults aged 3049 years and 5064 years (7). In addition, immunosenescence, the age-related decline in the functioning of the immune system, results in a less complete immune response to novel antigens and a reduced ability to develop robust immunity after infections or vaccination (8). The pool of naive T-cells diminishes with age, and this insufficient naive T-cell pool affects the ability to generate neutralizing antibody responses and cytotoxic T-cells in response to SARS-CoV-2 (9).

Thus, adults aged 65 years are more likely than are younger adults, adolescents, and children to rely upon vaccination to increase immunity that might have waned and might need more frequent vaccine doses to maintain protection. Coverage with the updated COVID-19 vaccine among adults aged 65 years was 42% as of February 3, 2024 (10,11). Adults in this age group are more concerned about COVID-19 disease and had higher confidence in COVID-19 vaccine safety and vaccine importance than did younger adults (5). A nationally representative survey conducted during November 2023January 2024 indicated that 68.4% of adults aged 65 years who had received an updated COVID-19 vaccine dose definitely would get another updated vaccine if it were recommended, 27.2% probably would or are unsure if they would get another updated vaccine, and 4.4% said they probably or definitely would not. COVID-19 vaccines are currently on the commercial market, but access-related barriers and disparities in vaccine coverage remain (5); in the absence of any recommendations for an additional dose, access to vaccine would be limited among persons unable to pay out of pocket for the vaccine.*

On February 28, 2024, ACIP voted to recommend that all persons aged 65 years receive 1 additional dose of any updated COVID-19 vaccine (i.e., Moderna, Novavax, or Pfizer-BioNTech). This recommendation was based on continuing SARS-CoV-2 circulation throughout the year, increased risk for severe illness attributable to COVID-19 in adults aged 65 years, protection provided by the updated vaccines against JN.1 and other currently circulating variants, the expected waning of SARS-CoV-2 immunity, and additional implementation considerations, including facilitating clear communication and equitable access to vaccine (5).

In 2018, ACIP adopted the Evidence to Recommendations framework to guide the development of vaccine recommendations. Since November 2023, the ACIP COVID-19 work group met seven times to discuss the current policy question, i.e., whether adults aged 65 years should receive an additional dose of updated COVID-19 vaccine. Work group membership included ACIP voting members, representatives of ACIP ex officio and liaison organizations, and scientific consultants with expertise in public health, immunology, medical specialties, and immunization safety and effectiveness. Work group discussion topics included COVID-19 disease surveillance and epidemiology; COVID-19 vaccination coverage; and the safety, effectiveness, feasibility of implementation, and cost effectiveness of COVID-19 vaccines. This report summarizes the ACIP recommendation for an additional dose of the updated COVID-19 vaccine for persons aged 65 years and the rationale, including evidence reviewed by the work group and presented to ACIP (https://www.cdc.gov/vaccines/acip/recs/grade/covid-19-additional-dose-adults-etr.html).

No clinical trial immunogenicity data on an additional dose of the updated COVID-19 vaccines exist; however, the initial dose elicits a robust neutralizing antibody response and provides protection against JN.1 and other circulating variants (12,13). Early vaccine effectiveness (VE) estimates demonstrate that updated COVID-19 vaccination provided increased protection against symptomatic SARS-CoV-2 infection and COVID-19associated emergency department and urgent care visits and hospitalization, compared with receipt of no updated vaccine dose (12,14). Although these early VE estimates show no substantial waning, based on data on effectiveness of original and bivalent COVID-19 vaccines, waning of vaccine-conferred immunity is expected. Effectiveness of an additional dose in older adults has been demonstrated for previously recommended additional original COVID-19 vaccine doses (15). Among adults aged 50 years who were eligible to receive a second original monovalent mRNA COVID-19 vaccine booster dose, VE against COVID-19associated emergency department and urgent care encounters during the SARS-CoV-2 Omicron BA.2/BA.2.12.1 period 120 days after the third dose was 32% but increased to 66% 7 days after the fourth dose. VE against COVID-19associated hospitalization 120 days after the third dose was 55% but increased to 80% 7 days after the fourth dose (15). In addition, in a large cohort of nursing home residents during circulation of SARS-CoV-2 Omicron subvariants, receipt of a second original monovalent mRNA COVID-19 booster dose 60 days earlier was 74% effective against severe COVID-19related outcomes (including hospitalization or death) and 90% effective against death, compared with receipt of a single booster dose (16).

COVID-19 vaccines have a favorable safety profile as demonstrated by robust safety surveillance during 3 years of COVID-19 vaccine use (17). Anaphylactic reactions have rarely been reported after receipt of COVID-19 vaccines (18). A rare risk for myocarditis and pericarditis exists, predominately in males aged 1239 years (19). No new safety concerns have been identified for the updated COVID-19 vaccine (5). Among adults aged 65 years, overall reactogenicity after COVID-19 vaccination is less frequent and less severe than among adolescents and younger adults (20). A statistical signal for ischemic stroke after Pfizer-BioNTech bivalent mRNA COVID-19 vaccine was detected in the CDC Vaccine Safety Datalink among persons aged 65 years, and information about this detection has been presented at previous ACIP meetings. Ongoing efforts to evaluate the signal have not identified any clear and consistent evidence of a safety concern for ischemic stroke with bivalent mRNA COVID-19 vaccines either when given alone or when given simultaneously with influenza vaccines (21). A recent VE study indicated that the bivalent COVID-19 vaccine was 47% effective in preventing COVID-19 related thromboembolic events (ischemic stroke, myocardial infarction, and deep vein thrombosis) among persons aged 65 years (22).

ACIP considered whether an additional dose of updated COVID-19 vaccine in persons aged 65 years is a reasonable and efficient allocation of resources. The societal incremental cost-effectiveness ratio (ICER) for an additional dose of COVID-19 vaccine in persons aged 65 years was $255,122 per quality-adjusted life year saved for the base case estimate. ICER values were sensitive to probability of hospitalizations, costs, and seasonality assumptions. Estimates of ICER values that approximate cost effectiveness for those with higher risk for COVID-19associated hospitalization, such as persons with underlying conditions or those aged 75 years, were more favorable (23).

On February 28, 2024, ACIP recommended that all persons aged 65 years receive 1 additional dose of any updated COVID-19 vaccine (i.e., Moderna, Novavax, or Pfizer-BioNTech). This additional dose should be administered 4 months after the previous dose of updated COVID-19 vaccine. For initial vaccination with Novavax COVID-19 vaccine, the 2-dose series should be completed before administration of the additional dose. Because Novavax COVID-19 vaccine is currently authorized under Emergency Use Authorization, the recommendation for the updated Novavax COVID-19 vaccine is an interim recommendation.

Persons aged 65 years who are moderately or severely immunocompromised, have completed an initial series, and have received 1 updated COVID-19 vaccine dose should receive 1 additional updated COVID-19 vaccine dose 2 months after the last dose of updated vaccine. Further additional doses may be administered, guided by the clinical judgment of a health care provider and personal preference and circumstances. Any further additional doses should be administered 2 months after the last COVID-19 vaccine dose. Additional clinical considerations, including detailed schedules and tables by age for all age groups and vaccination history for those who are or are not moderately or severely immunocompromised, are available at https://www.cdc.gov/vaccines/covid-19/clinical-considerations/covid-19-vaccines-us.html.

Adverse events after vaccination should be reported to the Vaccine Adverse Event Reporting System (VAERS). For licensed COVID-19 vaccines administered to persons aged 12 years, reporting is encouraged for any clinically significant adverse event even when whether the vaccine caused the event is uncertain, as well as for vaccination errors. For COVID-19 vaccines given under Emergency Use Authorization, vaccination providers are required to report certain adverse events to VAERS. Additional information is available at https://vaers.hhs.gov or by telephone at 1-800-822-7967.

Karen Broder, Mary Chamberland, Demetre Daskalakis, Susan Goldstein, Aron Hall, Elisha Hall, Fiona Havers, Andrew Leidner, Pedro Moro, Sara Oliver, Ismael Ortega-Sanchez, Kadam Patel, Manisha Patel, Amanda Payne, Huong Pham, Jamison Pike, Lauren Roper, Sierra Scarbrough, Tom Shimabukuro, Benjamin Silk, John Su, Evelyn Twentyman, Eric Weintraub, David Wentworth, Melinda Wharton, Michael Whitaker, JoEllen Wolicki, Fangjun Zhou, CDC. Voting members of the Advisory Committee on Immunization Practices (in addition to listed authors): Wilbur Chen, University of Maryland School of Medicine; Sybil Cineas, Warren Alpert Medical School of Brown University; Camille Kotton, Harvard Medical School; James Loehr, Cayuga Family Medicine; Sarah Long, Drexel University College of Medicine. Members of the Advisory Committee on Immunization Practices COVID-19 Vaccines Work Group: Beth P. Bell, University of Washington; Edward Belongia, Center for Clinical Epidemiology & Population Health, Marshfield Clinic Research Institute; Henry Bernstein, Zucker School of Medicine at Hofstra/Northwell Cohen Childrens Medical Center; Uzo Chukwuma, Indian Health Service; Paul Cieslak, Christine Hahn, Council of State and Territorial Epidemiologists; Richard Dang, American Pharmacists Association; Jeffrey Duchin, Infectious Diseases Society of America; Kathy Edwards, Vanderbilt University Medical Center; Sandra Fryhofer, American Medical Association; Jason M. Goldman, American College of Physicians; Robert Hopkins, University of Arkansas for Medical Sciences; Michael Ison, Chris Roberts, National Institutes of Health; Lisa A. Jackson, Jennifer C. Nelson, Kaiser Permanente Washington Health Research Institute; Denise Jamieson, American College of Obstetricians and Gynecologists; Jeffery Kelman, Centers for Medicare & Medicaid Services; Kathy Kinlaw, Center for Ethics, Emory University; Alan Lam, U.S. Department of Defense; Grace M. Lee, Stanford University School of Medicine; Lucia Lee, Anuga Rastogi, Adam Spanier, Rachel Zhang, Food and Drug Administration; Valerie Marshall, Office of the Assistant Secretary for Health, U.S. Department of Health and Human Services; Dayna Bowen Matthew, George Washington University Law School; Preeti Mehrotra, Society for Healthcare Epidemiology of America; Kathleen Neuzil, Center for Vaccine Development and Global Health, University of Maryland School of Medicine; Sean OLeary, American Academy of Pediatrics; Christine Oshansky, Biomedical Advanced Research and Development Authority; Stanley Perlman, Department of Microbiology and Immunology, University of Iowa; Marcus Plescia, Association of State and Territorial Health Officials; Rob Schechter, National Foundation for Infectious Diseases; Kenneth Schmader, American Geriatrics Society; Peter Szilagyi, University of California, Los Angeles; H. Keipp Talbot, Vanderbilt University School of Medicine; Jonathan Temte, American Academy of Family Physicians; Matthew Tunis, National Advisory Committee on Immunization Secretariat, Public Health Agency of Canada; Matt Zahn, National Association of County and City Health Officials; Nicola P. Klein, Kaiser Permanente Northern California; Cara B. Janusz, Lisa Prosser, Angela Rose, University of Michigan.

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Use of an Additional Updated 20232024 COVID-19 Vaccine Dose for Adults Aged 65 Years: Recommendations of ... - CDC