![LONDON, ENGLAND - JUNE 19: A woman receives a vaccine at the Chelsea F.C. pop up vaccine hub on June 19, 2021 in London, England. Chelsea F.C. is offering Covid-19 jabs to all eligible locals over the age of 18. (Photo by Hollie Adams/Getty Images)](https://thenational-the-national-prod.cdn.arcpublishing.com/resizer/v2/IL4WDPIIS4LUKNE5C2UJKEXKBY.jpg?smart=true&auth=70e6c49b47825807a0d207860a3c9a2edc69b5775470b999f99b13c9369f032e&width=400&height=225)
A woman receives a vaccine at the Chelsea FC pop-up vaccine hub on June 19, 2021 in London, England. Getty Images
A woman receives a vaccine at the Chelsea FC pop-up vaccine hub on June 19, 2021 in London, England. Getty Images
WHO estimates Covid-19 boosters needed yearly for most vulnerable
An internal document shows the WHO thinks annual boosters will be required for high-risk individuals