As the world approaches the second anniversary of the declaration of the Covid-19 pandemic by the World Health Organization, on March 11, more nations are rolling out — or are discussing the possibility of — fourth doses of coronavirus vaccine for their most vulnerable. In the United States, leading public health officials say they are “very carefully” monitoring if or when fourth doses might be needed, reported by CNN.
Israel was the first nation to roll out fourth doses, announcing in December that adults 60 and older, medical workers and people with suppressed immune systems were eligible to receive the extra shot if at least four months have passed since their third dose.
The United States has seen significant improvements recently in Covid-19 cases, hospitalizations and deaths. As of Friday, cases were down 44% from the prior week, hospitalizations dropped 26%, and deaths were 13% lower, according to Johns Hopkins University data.
“Vaccination and boosting will be critical in maintaining that downward trajectory, particularly when you’re talking about the red curve of severe disease leading to hospitalization,” Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, said during a White House Covid-19 Task Force briefing Wednesday.
The “potential future requirement” for an additional boost or a fourth shot of the Pfizer/BioNTech or Moderna mRNA vaccines or a third dose of the Johnson & Johnson vaccine “is being very carefully monitored in real time,” Fauci said. “And recommendations, if needed, will be updated according to the data as it evolves.”
The CDC has no recommendation of fourth doses of coronavirus vaccine for the general public, but the agency updated its guidelines in October to note that certain people who are moderately or severely immunocompromised may receive a fourth dose of the Moderna or Pfizer/BioNTech vaccines.
“For the immunocompetent people, a single booster shot continues to provide high levels of protection against severe disease caused by Omicron,” Fauci said Wednesday. “This should not be confused with the fact that for many immunocompromised people, already a second booster shot — namely a fourth dose of an mRNA — is recommended because of what we know about their poor response to the initial regimen.”
More recently, the Public Health Agency of Sweden announced last week that second booster doses are recommended for everyone 80 and older in the country. The United Kingdom’s Department of Health and Social Care announced Monday that an extra booster dose of coronavirus vaccine will be offered in the spring to adults 75 and older, residents in care homes for older adults and immunosuppressed people 12 and older.
In the United States, health officials emphasized late last year that fourth doses were not yet needed and said it was too premature to be discussing a potential fourth dose of coronavirus vaccine for most people.
Now, the US Food and Drug Administration “is indeed continually looking at the emerging data on the pandemic and variants in the United States and overseas in order to evaluate the potential utility and composition of booster doses,” FDA spokesperson Alison Hunt wrote in an email to CNN on Friday.
She confirmed that although Dr. Peter Marks, director of the FDA’s Center for Biologics Evaluation and Research, has noted that there is still much uncertainty as to how the pandemic may further evolve, he also has said it is possible that a fourth dose might be recommended as we move into fall.
A fall timeline coincides with the administration of flu shots, which could be convenient for people and makes sense scientifically because respiratory viruses — like the coronavirus and influenza — tend to peak in the winter months that follow.
“As more data become available about the safety and effectiveness of COVID-19 vaccines, including the use of a booster dose, we will continue to evaluate the rapidly changing science and keep the public informed,” Hunt wrote. “Any determination that additional booster doses are needed will be based on data available to the agency.”
If or when the FDA authorizes a fourth dose for the public, the next step would be for the US Centers for Disease Control and Prevention to review the data before making a recommendation for use, as the agency has done for other coronavirus vaccine recommendations.
Meanwhile, vaccine makers continue to study fourth doses in broader populations.