Trials of third ‘booster’ vaccine to fight COVID variants to start

Vaccine makers are developing a third shot to fight new, highly contagious COVID-19 variants — with clinical trials set to start this month, Dr. Anthony Fauci said Wednesday.

Moderna and other firms are working hard to seek approval for “variant-specific” booster jabs to protect against mutated virus strains such as the South African variant, the National Institute of Allergy and Infectious Diseases chief said during a White House briefing.

“The approach taken by some companies, in this case Moderna, is to begin clinical trials of a booster shot against the specific variant in question. And in this case it’s the [B1.351 strain] from South Africa,” Fauci said.

“It’s a planned study that will begin in the middle of this month and it will be done in collaboration with our group at NIAID, in which we will look at both naive [untreated] and previously vaccinated adults.”

Fauci stressed that the level of protection provided by current Moderna and Pfizer vaccines “diminishes by five or sixfold” when a person contracts a COVID-19 variant.

But he said the shots still offer a “considerable cushion” of protection from illness.

Pfizer — which said last week it is also studying booster shots — is also working to target mutated strains, Fauci said.

The Pfizer study will monitor the safety and efficacy of a third dose among two age groups of people, who first received the Pfizer vaccine in a clinical trial last May.

Fauci also suggested a possible “universal coronavirus vaccine” may be developed in coming years to battle variants.

“We look to the future … a universal coronavirus vaccine would handle variants of SARS-CoV-2 and would hopefully be able to address other coronaviruses in the future,” Fauci said at the briefing without elaborating. 

Several COVID-19 variants, including the South African, Brazilian and UK strains, have emerged in the US in recent months. The UK variant is believed to be up to 70 percent more contagious.

On Tuesday, the Brazilian variant was found in Oregon in the first known case of the new strain in the US.