Anthony Fauci
Anthony FauciReuters

Dr. Anthony Fauci, US President Joe Biden’s chief medical adviser, said on Thursday that it is not clear yet if people will need yearly COVID-19 boosters, even as the chief executives of several drugmakers have indicated a fourth vaccine dose may be necessary.

"We've only recently boosted people. We will find out if the booster gives you a degree of durability of protection and actually should be the standard regimen of three doses of an mRNA and two doses of J&J," Fauci said in an interview with NBC News and quoted by The Hill.

"Or — and it's a big 'or' right now — will we need to boost people every year or so?" he continued.

Fauci said that he while it was a good thing that the original ancestral strain of COVID-19 was used in the development of the COVID-19 vaccine — because “we were fortunate that even though [strains] were different, they were not so different that the vaccine didn't cover it well" — Omicron has muddled the situation.

"We were doing quite well with a primary vaccination and a boost with Delta. Then all of a sudden Omicron came along. And if you look at the efficacy against the Delta versus Omicron, it went down to around 30 percent," he told NBC.

Fauci added that he wants a vaccine that would ideally be effective against all kinds of COVID-19 variants.

The European Union’s vaccine regulatory agency warned this week that repeated use of COVID vaccine boosters could impair the booster recipient’s immune response, potentially “overloading” the immune system.

Speaking at a press briefing Tuesday, members of the European Health Medicines Agency’s Biological Health Threats and Vaccines Strategy committee discussed proposals to use a fourth dose of the COVID vaccine, following the decision by Israel to offer a second booster shot to elderly citizens and healthcare workers.

Marco Cavaleri, chief of the agency’s vaccines committee, warned against the overuse of booster shots, saying they cannot be “repeated constantly.”

“We are rather concerned about a strategy that entangles repeated vaccinations within a short term.”

“We cannot really continuously give booster doses every 3-4 months.”