Israeli health officials say they have found 275 cases of myocarditis in young men.
The Ministry of Health in Israel has said it observed a link between heart inflammation in young men and the Pfizer vaccine which has been administered to over 5 million people in the country.
Occurring between December and May, most of the patients spent less than five days in hospital, with 95 per cent of cases considered mild.
The study found “there is a probable link between receiving the second dose (of Pfizer) vaccine and the appearance of myocarditis among men aged 16 to 30,” the team of three experts said in a statement.
Pfizer/BioNTech however said no causal link between heart inflammation and their vaccine has been proved, as Israel considers offering the jab to children between 12 and 15 years old following authorization among the group by the US Food and Drug Administration.
“The (Covid-19 health) committee gave the green light for vaccinating 12- to 15-year-olds, and this will be possible as of next week,” Israel’s pandemic-response coordinator Nachman Ash insisted.
“The efficacy of the vaccine outweighs the risk.”
Whilst half of those affected by myocarditis after the vaccine had pre-existing medical conditions, 148 of the cases were identified within a month of vaccination, 27 of which occurred after the first dose and 121 after the second dose.
The 16-19 year-old male group were worst affected by heart inflammation, which Pfizer says could be caused by viral infections and Covid-19 itself.
“A careful assessment of the reports is ongoing and it has not been concluded,” a Pfizer statement said.
“Adverse events, including myocarditis and pericarditis, are being regularly and thoroughly reviewed by the companies as well as by regulatory authorities.”
55 per cent of of the Israeli population has now been vaccinated.