There is no need yet for a Coronavirus vaccine booster shot, said a group of international experts after reviewing studies about vaccine performance.

In an opinion piece published in scientific journal The Lancet, the experts said that the vaccines are working well, despite the fast spread of the Delta variant.

They pointed out that within highly vaccinated populations, "The unvaccinated are still the major drivers of transmission” of the virus. Their statement comes in the context of the ongoing scientific debate about the efficacy of booster shots.

Among the experts are two leading vaccine reviewers at the Food and Drug Administration (FDA) and other leading vaccine researchers from the US, Britain, France, South Africa and India, as well as World Health Organization (WHO) scientists.

The White House is awaiting the FDA and Centers for Disease Control and Prevention's decision on utilizing booster shots, and has begun planning to take action.

It is noteworthy to mention that the US is already offering an extra Pfizer or Moderna dose to people with weak immune systems.