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Health officials said Wednesday they are preparing to offer COVID-19 vaccine booster shots to adults as early as mid-September, pending regulatory approval. Recommendations for adolescents have not been made at this time.
As the highly transmissible delta variant spreads across the country, new data show vaccine effectiveness against mild to moderate disease is decreasing, although it remains strong against severe illness.
“Even though this new data affirms that vaccine protection remains high against the worst outcomes of COVID, we are concerned this pattern of decline we are seeing will continue in the months ahead which could lead to reduced protection against severe disease, hospitalization and death,” Surgeon General Vivek H. Murthy, M.D., M.B.A., said.
Officials are calling for adults to receive boosters eight months after their second dose of mRNA Pfizer-BioNTech or Moderna vaccines beginning as early as the week of Sept. 20, 2021. Health care workers were among the first vaccinated and therefore will be among the first eligible for a booster. Before that can happen, the Food and Drug Administration (FDA) must review data on safety and effectiveness and give its approval, which would be followed by recommendations from the Centers for Disease Control and Prevention’s (CDC’s) Advisory Committee on Immunization Practices (ACIP).
The Pfizer-BioNTech vaccine initially was granted emergency use authorization for people as young as 16 years, which was lowered to 12 years in May. Health officials said their booster plans apply only to adults, although they did not rule out the additional shots for adolescents.
“When it comes to 16- and 17-year-olds and minors in general, we are going to let the FDA weigh in on that, obviously do their thorough review and then based on their recommendations and ACIP’s recommendations, we will have guidance to share for those who are under 18,” Dr. Murthy said.
The plans do not apply to the Johnson & Johnson vaccine as officials are still gathering more data.
Wednesday’s announcement comes less than a week after the FDA and CDC approved a third dose of mRNA vaccine for certain people who are immunocompromised and therefore may not have developed a sufficient immune response to two doses.
The CDC released three studies in the Morbidity and Mortality Weekly Report Wednesday supporting the need for booster doses.
One study of fully vaccinated adults in New York found effectiveness against infection declined from 92% in May to 80% in late July. In another study, the vaccines were 75% effective at preventing infection among nursing home residents in the spring. However, after the delta variant began to circulate widely, effectiveness declined to 53%. Authors said the decrease could have been due to the passage of time or the variant.
CDC Director Rochelle P. Walensky, M.D., M.P.H., also cited a preprint article from Mayo Clinic that found from January to July, effectiveness against SARS-CoV-2 infection declined from 76% to 42% for the Pfizer-BioNTech vaccine and 86% to 76% for the Moderna vaccine. This study has not been peer-reviewed.
“Given this body of evidence, we are concerned that the current strong protection against severe infection, hospitalization and death could decrease in the months ahead, especially among those who are at higher risk or who were vaccinated earlier during the phases of our vaccination rollout,” Dr. Walensky said.
Currently, protection against severe illness appears high. The New York study found although effectiveness against infection declined, effectiveness against hospitalization stayed relatively stable, remaining at 92% or higher. Another study looking at protection against hospitalization found effectiveness of 86% two to 12 weeks after vaccination and 84% effectiveness 13-24 weeks after vaccination.
Anthony Fauci, M.D., President Biden’s chief medical adviser, said higher levels of antibodies are associated with higher vaccine effectiveness and may be needed to fight off the delta variant. He expects booster doses to increase antibody titers at least 10-fold.
Continued vaccination efforts
About 51% of the population is fully vaccinated, according to CDC data. Among those who are eligible, about 60% are fully vaccinated. The U.S. has seen hospitalization and death rates rising in recent weeks, largely in people who are not vaccinated. Officials said they would continue to push for all eligible people to get vaccinated.
“Our vaccines continue to offer the best protection against severe COVID illness,” Dr. Walensky said. “While we are still learning about how these vaccines perform over time and how long they will last against emerging variants, one thing is very clear. Getting vaccinated keeps you out of hospital. Getting vaccinated can save your life.”
Just before Wednesday’s announcement on boosters, the World Health Organization (WHO) praised the U.S. for sharing more vaccine doses with other countries than any other nation. It has donated 115 million doses and committed to 600 million doses. However, the WHO has been critical of countries offering booster doses.
“The divide between the haves and have nots will only grow larger if manufacturers and leaders prioritize booster shots over supply to low- and middle-income countries,” WHO Director-General Tedros Adhanom Ghebreyesus, Ph.D., M.Sc., said during a press conference. “The virus is evolving, and it is not in the best interests of leaders just to focus on narrow nationalistic goals when we live in an interconnected world and the virus is mutating quickly.”
U.S. officials highlighted their efforts to provide doses around the world and pushed back on the criticism of boosters.
“I do not accept the idea we have to choose between America and the world,” Dr. Murthy said. “We clearly see our responsibility to both. We’ve got to do everything we can to protect people here at home while recognizing that tamping down the pandemic across the world and getting people vaccinated is going to be key to preventing the rise of future variants.”