UK vaccine chief warns of over-optimism, early imperfection

LONDON (AP) — Warning that the first COVID-19 vaccines may be imperfect, the head of the U.K effort to develop a vaccine called Wednesday for immediate international cooperation to prevent the “largest global recession in history.’’

U.K. Vaccine Taskforce chair Kate Bingham also warned against over-optimism, saying there is no guarantee a successful vaccine against the novel coronavirus will ever be developed.

“The first generation of vaccines is likely to be imperfect, and we should be prepared that they might not prevent infection, but rather reduce symptoms, and, even then, might not work for everyone or for long,’’ Bingham wrote in an essay published in The Lancet medical journal.

No vaccine has ever been developed against any coronavirus, and numerous attempts to design vaccines against SARS and MERS, two which are related to the virus that causes COVID-19, have failed. Scientists also warn that immunity against coronaviruses appears to fade over time and that achieving any vaccine-induced immunity to protect against infection or severe disease could be challenging.

Bingham’s comments come as government leaders in Britain and other countries are basing their COVID-19 strategies on expectations of a vaccine becoming available as soon as early next year.

Prime Minister Boris Johnson, for example, has implemented a three-tiered regional strategy aimed at slowing the spread of the disease until there is a vaccine while also minimizing the economic damage from another widespread lockdown.

Meanwhile, coronavirus cases, hospitalizations and deaths in the U.K. and elsewhere in Europe are rising amid a second wave of infections.

Britain created the Vaccine Taskforce earlier this year to speed the development of a vaccine. Two candidates are in late stage...