https://apnews.com/466726258e5e546550907f123f67763d > AstraZeneca insisted Wednesday that its COVID-19 vaccine is strongly effective even after counting additional illnesses in its disputed U.S. study, the latest in an extraordinary public rift with American officials. > In a late-night press release, AstraZeneca said it had recalculated data from that study and concluded the vaccine is 76% effective in preventing symptomatic COVID-19, instead of the 79% it had claimed earlier in the week.