

AstraZeneca reiterated on Wednesday that its Covid-19 vaccine was very effective at preventing the disease, based on more recent data than was included when the company announced the interim results of its U.S. clinical trial on Monday.
The company said in a news release that its vaccine was 76 percent effective at preventing Covid-19. That is slightly lower than the number that the company announced earlier this week.
The new results strengthen the scientific case for the embattled vaccine. But they may not repair the damage to AstraZeneca’s credibility after U.S. health officials and independent monitors issued an extraordinary rebuke of the company for not counting some Covid-19 cases when it announced its initial findings this week.
In a news release on Wednesday, the company said complete results from its 32,000-person study showed that its vaccine was 76 percent effective. On Monday, the company had said the vaccine appeared to be 79 percent effective, based on an interim look at 141 Covid-19 cases that had turned up among volunteers before Feb. 17. The latest finding was based on 190 trial participants who had gotten sick with Covid-19.
public statement.
said last week that a review had found the shot to be safe after a small number of people who had recently been inoculated developed blood clots and abnormal bleeding. The U.S. trial did not turn up any signs of such safety problems.