Immunology experts have not concluded that more COVID-19 boosters are necessary despite Pfizer and Moderna's efforts to promote the shots, Kaiser Health News reported March 21.
On March 13, Pfizer CEO Albert Bourla, PhD, said a second booster shot of the COVID-19 vaccine is necessary for protection against infection. Many COVID-19 experts criticized Dr. Bourla's announcement, saying it lacked scientific merit and confused the public about the country's objectives in its fight against the disease.
Statements such as Dr. Bourla's pressure regulatory bodies to approve additional shots before government experts can examine evidence, John Moore, PhD, an immunology professor at Weill Cornell Medical College in New York City, told Kaiser Health News.
Phil Krause, MD, a former deputy director of the FDA’s biologics center, said Dr. Bourla's announcement was based on a Israeli study that has not been peer reviewed. The study assessed patients only a few weeks after they had received their fourth vaccine dose. Dr. Krause said the limited scope of the data means clarity cannot be achieved regarding a fourth shot's duration of protection.
Vaccine experts are also skeptical about whether frequent boosters can improve protection against infection, as two or three vaccinations protect most people against serious illness but do little to prevent infection after three or four months.
Even amid this skepticism from experts, Pfizer and Moderna have made recent applications to the FDA for emergency use authorizations for fourth shots. Pfizer is seeking authorization for adults 65 and older while Moderna is seeking authorization for all adults.