Analysis: Can first COVID-19 vaccines bring herd immunity? Experts have doubts
FRANKFURT/LONDON (Reuters) – Governments and officials are voicing hopes that COVID-19 vaccines could bring “herd immunity”, with some calculating that immunising just two-thirds of a population could halt the pandemic disease and help protect whole communities or nations.
But the concept comes with caveats and big demands of what vaccines might be capable of preventing. Some experts say such expectations are misplaced.
For a start, figuring out what’s needed to achieve herd immunity with COVID-19 vaccines involves a range of factors, several of which are unknown.
What is the rate of the spread of the COVID-19-causing virus? Will the first vaccines deployed be able to stop transmission of the virus, or just stop people getting ill? How many people in a population will accept a vaccine? Will vaccines offer the same protection to everyone?
“Herd immunity is sometimes wrongly understood as individual protection,” said Josep Jansa, an expert in health emergency preparedness and response at the Stockholm-based European Centre for Disease Prevention and Control (ECDC).
“It’s inappropriate to think ‘I will not be affected myself because there is herd immunity’. Herd immunity refers to community protection, not to how an individual is protected.”