Israel's Health Ministry has identified fewer than 10 cases of heart inflammation following a third dose of the Pfizer/BioNtech vaccine among millions administered, according to recently released data.
Israel began administering boosters to risk groups in July and by the end of August expanded its campaign to include anyone above the age of 12, five months or more after a second dose.
In data published, the Health Ministry reported nine cases of myocarditis within four age groups that comprised more than 1.5 million people who had received a booster shot.
All were male, three were between the ages of 16 and 29 and six were in the 30-59 group. Eight more possible cases were still being reviewed. Most myocarditis cases are generally mild, the ministry said.
In total, out of all 3.2 million Israelis who have received a third jab, 25 reported serious adverse events that appeared within 30 days of the shot, including myocarditis, though a causal link had yet to be established among many of them.
The booster drive is being watched closely in the United States, where third Pfizer shots have been rolled out for those 65 and older, all people at high risk of severe disease, and others who are regularly exposed to the virus.