Global herd immunity is still out of reach

MORE THAN 5m Americans who have received a first dose of the covid-19 vaccine are skipping appointments for their second, according to the Centres for Disease Control and Prevention. Some mistakenly think they are sufficiently protected with a single shot; others fear side effects. Such hesitation is common around the world, according to a new poll by Gallup. In a survey of 300,000 people across 117 countries, the pollster found that only 68% of adults would agree to be vaccinated if a free jab were available to them; 29% said they would refuse.

Gallup found that people in richer countries tend to be slightly warier of covid-19 vaccines than those in poorer parts of the world. Only 59% of North Americans are willing to get a jab; in the United States the figure is just 53%. In Europe, 53% of respondents say they would surrender their arms to a vaccine, though western Europeans are generally keener than easterners. Elsewhere, people are more eager. In Africa and Latin America, 64% and 68% said they would agree to be vaccinated. In Asia as many as 76% reckon a jab is a safe bet (see chart).

Some countries are particularly vaccine-phobic. In France 40% of respondents said they would not agree to a jab. Past public-health scares, such as a scandal involving HIV-infected blood in the 1990s and a troubled vaccine rollout during the swine-flu pandemic in the 2010s, have damaged attitudes to inoculation.

Myanmar is the least sceptical, followed by neighbouring Laos and Thailand. Myanmar has historically enjoyed high vaccination coverage and trust in existing health-care systems even when its people have had little knowledge of a disease. In 2017, for example, almost all parents in Yangon, Myanmar’s largest city, got their children vaccinated against Japanese encephalitis, a lethal mosquito-borne illness.

The results paint a sobering picture of the prospects for herd immunity. By some estimates, it requires that 70-90% of a population be immune. (The exact number is not yet conclusively known.) But at current rates, even if everyone who wants the vaccine is able to get it, this will not be attainable. Responding to a question about herd immunity at a White House press briefing last month, Dr Anthony Fauci, the chief medical adviser to President Joe Biden, urged people to stop focusing on an elusive, magical number. Instead, he said, “let’s get as many people vaccinated as quickly as we possibly can”. Even if the virus continues to circulate for years to come, vaccinations can turn it into a more manageable threat.