People hand out information outside Marble Arch tube station in London Richard Baker/Getty Images
Throughout the covid-19 pandemic there has been constant reference to the tantalising phenomenon that signals the end: herd immunity. This is when enough people are immune to a virus that it can’t spread, therefore protecting the whole community, including those who aren’t immune.
More than 18 months into the pandemic, and with 59 per cent of the UK having received two doses of a covid-19 vaccine, how far is the country from the herd immunity threshold, and how will we know when it has got there?…
