LONDON — The announcement this week that the AstraZeneca shot, the workhorse of global vaccine rollouts, had achieved nearly 80 percent efficacy in a gold-standard American trial was met with relief by the many countries relying on it.
“When you get the call, get the jab,” the British health secretary, Matt Hancock, urged, part of a campaign by European lawmakers to calm people’s nerves after a recent safety scare with the shot.
But by Tuesday, that campaign had, once again, been thrown off course, at least for the moment. For AstraZeneca, it was seemingly another episode of public relations whiplash, part of a series of recent miscues and communication blunders by the company that scientists said had undercut the effort to sell one of the most potent and indispensable vaccines against the coronavirus.
In a highly unusual move, American health officials said on Tuesday that the company’s account of its U.S. trial findings had not been entirely accurate, suggesting that AstraZeneca had used only the most favorable data to generate apparently spectacular efficacy results.
developed unusual blood clots.
In France, Germany, Italy and Spain, more people now believe that the vaccine is unsafe than that safe, polling has shown, a blow to a shot that remains the continent’s best hope for saving people’s lives during a mounting surge of new infections. Millions of doses are sitting unused in refrigerators across the continent, with doctors reporting some people canceling injections over fears about side effects.
driving down hospitalizations and helping the country to emerge from a dreadful wintertime wave of infections.
Nevertheless, AstraZeneca’s U.S. trial was hotly anticipated. The largest of its kind for the shot, it had been expected to provide the cleanest, most complete picture of the vaccine’s efficacy. American officials saw it as an incontrovertible test of the vaccine’s performance.
And health officials around the world were looking to it as a crucial guide to their own rollouts: It would supply crucial data on older people, who had not been as well represented in earlier trials, and a more precise read on the vaccine’s overall efficacy, which had appeared from earlier trials to be lower than that of other leading shots.
As soon as AstraZeneca announced its results on Monday, saying that the vaccine had 79 percent efficacy in preventing symptomatic Covid-19, lawmakers began citing it as part of their fledgling efforts to shore up public confidence in the vaccine.