KEY POINTS
  • Dr. Kate O'Brien, the WHO's director of immunization, vaccines and biologicals, said the organization is still researching whether a booster shot is need to increase protection.
  • If the WHO endorsed a booster shot, O'Brien said it would likely only be for select groups of recipients, like the elderly.
  • O'Brien said the WHO is studying the durability of the vaccines, meaning how long protection lasts, before recommending a booster.
Student Jack Herrington receives a dose of a coronavirus disease (COVID-19) vaccine on the campus of the University of Memphis in Memphis, Tennessee, July 22, 2021.

The World Health Organization doesn't recommend Covid-19 booster shots "at this time," the group's top vaccine doctor said Wednesday, citing a lack of data on their effectiveness.

Dr. Kate O'Brien, the WHO's director of immunization, vaccines and biologicals, said the organization is still researching whether a booster shot is needed to increase protection against highly contagious mutations of the coronavirus.

Executives from Pfizer, Moderna and Johnson & Johnson, which make the three Covid vaccines authorized for use in the U.S., have all said Americans would eventually need a booster following their first series of vaccinations. Pfizer plans to submit its application to U.S. regulators for a booster dose in August, the company said earlier Wednesday.

"We're very clear on this, there's not enough information to provide a recommendation at this point," O'Brien said in a Q&A interview posted on the organization's social media accounts. "Again, this is a very hot topic, and there's a lot of research going on to be able to provide an evidence-based recommendation," she said.

If the WHO endorsed a booster shot, O'Brien said it would likely only be for select groups of recipients, like the elderly or people with other conditions that make them vulnerable to severe disease. She added that the WHO is also evaluating whether to approve booster shots "on a product-by-product basis, because not all the products are exactly the same."

O'Brien said the WHO is studying the durability of the vaccines, meaning how long protection lasts, as well as their effectiveness against different variants before recommending a booster.