About nine in 10 people who received a third dose of the Pfizer-BioNTech Covid-19 vaccine during an Israeli booster campaign reported similar or fewer side effects than they did after their second shot, an initial survey has found.
Israel began offering a third dose of the shot on July 30 to people aged over 60, as part of efforts to slow the spread of the highly contagious Delta variant of Covid-19.
Israel’s largest healthcare provider, Clalit, said on Sunday it had administered a third dose of the Pfizer-BioNTech vaccine to more than 240,000 people.
About 4,500 people, all of whom received the booster shot between July 30 and August 1, responded to questions and were included in the survey, Reuters reported.
Eighty-eight per cent of participants in the survey said that, in the days after receiving the third shot, they felt “similar or better” to how they felt after the second shot.
Thirty-one per cent reported some side effects, the most common being soreness at the injection site.
About 0.4 per cent said they suffered difficulty breathing, and 1 per cent said they sought medical treatment owing to one or more side effects.
Ran Balicer, Clalit’s chief innovation officer, said that even though the results were “initial and self-reported”, they allowed for a comparison of side effects with the second dose.
"It turns out that in most cases they are similar or less in the booster," he said.
“Although we do not yet have long-term research on the efficacy and safety of the third booster dose, for the personal risk management of any person aged 60-plus, these findings continue to point to the benefit of immunisation now, along with careful behaviour among adults and avoiding gathering in closed spaces,” Mr Balicer said.
The decision to offer a third dose was announced on Thursday by Israeli Prime Minister Naftali Bennett, making Israel the first country to offer a third dose of a western vaccine to its citizens on a wide scale.
″Israel is a pioneer in going ahead with the third dose for older people of the age of 60 and above,″ Mr Bennett said at the time.
More than 62 per cent of the country's population of 9.3 million have been vaccinated against Covid-19 as part of a mass inoculation campaign.
Drug companies Pfizer and BioNTech have asked US and European regulators to approve a booster dose following a two-shot regimen of their vaccine, based on evidence of greater risk of infection six months after inoculation.
The US Food and Drug Administration is aiming to approve the Pfizer-BioNTech booster shots by early September, The New York Times reported.
But the World Health Organisation has called for vaccine booster plans to be put on hold until at least the end of September to allow for vaccination rates to improve worldwide.