Three COVID-19 Vaccine Doses Better Than Two? Debate Over Third Booster Shot

Coronavirus Vaccine: Experts say it is too soon to know for sure if countries will need to organise a third vaccine round later in the year.

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.