Coronavirus

LONDON — The British government’s Chief Scientific Adviser Patrick Vallance has apologized for not being clear when he previously presented the concept of “herd immunity” as a potential way out of the coronavirus pandemic, saying he didn’t mean that was the government’s plan.

Herd immunity refers to the state where enough members of the population have acquired immunity to a disease so that it cannot spread within that group.

Speaking to MPs on the House of Commons health committee, Vallance stressed Tuesday that when he presented this concept at a press conference in mid-March, he did not mean that the U.K. should try to get immunity through this route. He reiterated that the strategy has always been trying to suppress the peak and keep it below the level at which the National Health Service can cope.


“I should be clear about what I was trying to say, and if I didn’t say this clearly enough then I apologize,” he said. “What I was trying to say was that, in the absence of a therapeutic, the way in which you can stop a community becoming susceptible to this is through immunity and immunity can be obtained by vaccination, or it can be obtained by people who have the infection.”

Vallance is the most senior government figure to have openly discussed herd immunity before the U.K. lockdown was announced. At a press conference on March 12, he said of the coronavirus: “Our aim is not to stop everyone getting it, you can’t do that. And it’s not desirable, because you want to get some immunity in the population. We need to have immunity to protect ourselves from this in the future.”

He fleshed this idea out on BBC Radio 4 the following morning, stating: “Our aim is to try and reduce the peak, broaden the peak, not to suppress it completely. Also, because the vast majority of people get a mild illness, to build up some degree of herd immunity as well, so that more people are immune to this disease.”

At Tuesday’s committee hearing, Vallance said evidence from around the world suggests the vast majority of people who have had coronavirus have “some form of antibody response,” adding that this “looks quite promising.”

However, he cautioned it is not yet known what level of protection people get after being infected with coronavirus. He said experts still need to solve three big questions: what level of immune protection those antibodies confer; whether people acquire absolute immunity, and whether someone can still carry the virus and be infectious after having developed antibodies.