Vaccine-rich countries are beginning programmes of COVID-19 vaccine booster shots, but what's the evidence for them? What does this mean for countries which have no vaccines? Prof. Sir Richard Peto lays out the current evidence and Prof. K. Srinath Reddy, president of the Public Health Foundation of India, discusses what booster shots mean for the rest of the world, and how India is currently coping with COVID-19 following the wave there in early 2021.

Further reading:
Considerations in boosting COVID-19 vaccine immune responses
https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(21)02046-8/fulltext