Update 6/30/22: The FDA has accepted the committee's recommendations and is advising manufacturers to develop bivalent boosters that include the omicron BA.4/5 spike protein. For the latest news on COVID-19, visit http://bit.ly/AAPNewsCOVID19.
The Food and Drug Administration’s (FDA’s) vaccine advisory committee is recommending adding a SARS-CoV-2 omicron component to vaccine boosters that could be rolled out in the fall to provide broader protection.
The FDA plans to use this input to decide on vaccine strain composition in July. It is not clear yet who will be recommended to get these boosters.
“None of us has a crystal ball, and we are trying to use every last ounce of what we can from predictive modeling and from the data we have that’s emerging to try to get ahead of a virus that has been very crafty,” said Peter Marks, M.D., Ph.D., director of the FDA's Center for Biologics Evaluation and Research.
FDA officials say they are concerned about reduced effectiveness of the current vaccines against the omicron variants that have been dominant since the winter in addition to waning immunity. Hospitalizations and deaths due to COVID-19 recently increased in older age groups, according to the Centers for Disease Control and Prevention (CDC).
“That combination of waning immunity, combined with the potential emergence of novel variants during a time this winter when we will move inside as a population, increases our risk of a major COVID-19 outbreak and for that reason we have to give serious consideration to a booster campaign this fall to help protect us during this period from another COVID-19 surge,” Dr. Marks said.
A booster is recommended for everyone 5 years and older. A second booster is recommended for adults ages 50 years and older and some people 12 years and older who are immunocompromised. About 67% of the U.S. population is fully vaccinated, and about half of those 12 years and older who are fully vaccinated have gotten a booster, CDC data show.
Moderna and Pfizer presented data showing an increase in antibody responses to omicron when an omicron component is included in a booster. The FDA’s Vaccines and Related Biological Products Advisory Committee (VRBPAC) voted 19-2 Tuesday in favor of including an omicron component in the boosters.
“In terms of severe disease, we are seeing breakthrough severe disease in people who are vaccinated with the prototype strain, so I think that is a strong argument to say we should be thinking about adding to the strain composition,” said VRBPAC member Archana Chatterjee, M.D., Ph.D., dean of the Chicago Medical School at Rosalind Franklin University of Medicine and Science.
The two VRBPAC members who voted against the omicron component in the booster said there are not enough data.
“I’m still not comfortable enough that we have the information that makes us essentially support this new product, and I don’t think it’s fair to ask people to take a risk with any vaccine that we get if we don’t feel comfortable with the level of protection we’re likely going to get by including omicron,” said VRBPAC member Paul Offit, M.D., FAAP, director of the Vaccine Education Center at Children’s Hospital of Philadelphia.
Others said waiting for more data would put efforts to fight the virus farther behind.
“I think with the waning in vaccine efficacy and confluence of risk this fall, we need to make a move sooner rather than later and direct our sponsors in the proper direction,” said VRBPAC member Michael R. Nelson, M.D., Ph.D., chief of the Asthma, Allergy and Immunology Division of UVA Health.
While the vote was solely about whether to include an omicron component, many said they would prefer a bivalent over a monovalent vaccine to maintain protection provided by the original vaccines and to make them broader.
The group felt an updated vaccine should contain the original strain and the omicron BA.4 or BA.5 sub-lineages, which have fewer vaccine data than other sub-lineages but combined have become dominant. Currently, about 42% of infections are omicron BA2.12.1 followed by 37% BA.5 and 16% BA.4, CDC data show.
Several VRBPAC members noted the data presented Tuesday focused on adults and called for more information on the safety and immunogenicity of omicron-specific vaccines in children.
“As we know, the youngest group just got approved a year and a half after the original approval in December of 2020 (for adults),” said VRBPAC member Jeannette Yen Lee, Ph.D., professor of biostatistics at the University of Arkansas for Medical Sciences. “My concern is if we don’t have a strategy, they will always be behind as the virus is evolving and they will never be getting vaccinated against the most recent strain.”
Moderna officials said they expect to have pediatric data on their omicron-containing vaccine in October. While there is some concern about side effects in children, some VRBPAC members pointed out trials aren’t likely to catch rare adverse events like myocarditis.
VRBPAC members and FDA officials acknowledged numerous challenges ahead, including whether to change the composition of the primary series vaccines, complicated implementation if the boosters are different from the primary series and the global impact if an omicron-specific vaccine is available only in the U.S. Members also continued to call for more data on cellular immunity as well as data to help them better interpret what antibody levels are needed to provide protection.
Resources
- CDC information on COVID-19 vaccine boosters
- CDC clinical considerations for administering COVID-19 vaccines
- Information from the CDC on COVID-19 vaccination of children and teens
- AAP COVID vaccination resources
- AAP pediatric COVID-19 vaccine dosing quick reference guide
- AAP/Health and Human Services COVID vaccine toolkit
- Information from HealthyChildren.org on preparing children for a COVID-19 vaccine
