UK races toward elusive milestone in quest to curb Covid

The U.K.’s increased Covid-19 immunity raises prospects of moving on from the worst of the pandemic, with some scientists saying the country could cross a key threshold as soon as Monday.
According to researchers at University College London, that’s when so-called herd immunity could be achieved in the U.K. Almost three-quarters of the population will have antibodies against the virus, either through vaccination or past infection, they estimate.
Britain has already seen a plunge in new cases and deaths, and the government will relax restrictions, including on outdoor dining, on Monday. Those developments have fueled hopes that the nation will soon shake off its Covid shackles.
Many other scientists think the U.K. is much further from herd immunity than UCL’s model suggests. It’s come under fire from some who say it overestimates the strength of vaccines and doesn’t adequately account for waning immunity and new virus variants. No more than 44% of the country has protection from Covid, according to estimates by Imperial College London.
“There’s a lot of uncertainty about the length of immunity, both vaccine immunity and natural immunity,” said Anne Cori, a lecturer at Imperial. “If immunity is waning, you might lose herd immunity after you reach it.”
Still, the progress marks a milestone for the European country hardest hit by the pandemic, with more than 127,000 fatalities, and for Prime Minister Boris Johnson, who was criticized for a slow response to the crisis.
In the early days, his government’s chief scientific adviser suffered a backlash after speaking about the U.K.’s apparent ambition to “build up some degree of herd immunity” – exposing a proportion of the population to the virus – but he has since insisted this was never official policy and claims he was misinterpreted.
Virologists describe herd immunity as the point at which a virus struggles to make inroads into a society because of high immunity levels, either through vaccination or previous exposure to the pathogen. If it’s elusive for the U.K., for most of the rest of the world it’s still a distant dream. Experts agree that speeding up vaccinations is the surest way to bring the virus under control, and in that regard Britain is out in front of most other nations.
Almost half of Britons have received at least one vaccine dose, compared with just over a third of Americans and 14% of EU residents, according to Bloomberg’s Vaccine Tracker. Still, after becoming an epicenter of a fresh Covid surge, there are tentative signs that Western Europe is turning the corner.
On Thursday, France hit a target of giving a first jab to 10 million people, a week ahead of schedule. Germany vaccinated 720,000 people that day, a record for the nation, and aims to comprehensively inoculate its population by mid-summer. As supplies ramp up, Europe’s largest economy could administer 3.5 million doses a week, according to Health Minister Jens Spahn.
Even so, European nations will likely lag behind Britain in fully vaccinating 75% of their populations, according to analysis by Airfinity Ltd., a London-based research firm. While the U.K. is set to reach that level by early August, Germany won’t get there until September and France until October, the firm’s current estimates show.
The European Commission is looking to ensure a steady supply of vaccines in coming years, to avoid the shortages that have hobbled immunization campaigns in the bloc.
Shots may be needed for years to come, especially if the virus continues to mutate and circulates at lower levels, much like the flu.
“Longer-term, it’s going to be more like an epidemic where there are sometimes outbreaks and you’ll need to manage that,” said Matt Linley, a senior analyst at Airfinity. Todd Gillespie, Bloomberg