Three doses better than two? Debate over third shot

NEW YORK: As the Delta variant spreads rapidly throughout the world, the prospect of a third “booster” shot is gaining interest even in nations where a large proportion of people are vaccinated. Experts say it is too soon to know for sure if countries will need to organise a third vaccine round later in the year. Some suggest that priority should be given to hundreds of millions in the global south who have not even gotten their first jab yet.

Why three?

Earlier this month, manufacturers Pfizer/BioNTech said they would ask US and European authorities for permission to provide a third dose of their vaccine. They said this was aimed at ensuring stronger immunity in individuals than that bestowed by two doses. The developers said that two doses of their vaccine protected against severe Covid-19 for at least six months.

But faced with emerging variants, they said they anticipated some decline in efficacy over time. The White House’s chief medical advisor Anthony Fauci, speaking on CNBC on Tuesday, said Pfizer/BioNTech’s third-dose application was “an appropriate preparation (for) the eventuality that you might need a booster”.

“But when you translate that into, ‘We will need a booster, everyone’s going to get a booster,’ that is not appropriate,” Fauci said.

He added that there were still too many people who are not fully vaccinated with two doses, let alone three.

What do authorities say?

There is currently no sign that medical agencies will recommend a third dose for everyone who has already received two.

The European Medicines Agency and the European Centre for Disease Control says it is still too early to tell if a third dose is needed.

“There is not yet enough data from vaccination campaigns and ongoing studies to understand how long protection from the vaccines will last, also considering the spread of variants,” they said in a joint statement.

Didier Houssin, director of the World Health Organization’s emergency committee, said he didn’t believe there was enough evidence to justify recommending a third dose at this point.

He also warned that talk of a third dose could “aggravate concerns over access to vaccines” at a time where most countries have only a tiny percentage of people fully inoculated.