Israeli Covid study finds fourth Pfizer vaccine dose shields elderly

Findings revealed before US Food and Drug Administration meeting to discuss need for additional boosters

'The New England Journal of Medicine' has published results of a latest study of booster Covid-19 vaccines. AFP

A second booster of the Pfizer-BioNTech coronavirus vaccine lowered rates of Covid-19 among the elderly but the protection against infection appeared short-lived, a study in Israel has found.

Protection against infection after receiving the second booster – or fourth dose – dwindled after four weeks, Israeli researchers noted in their study published on Tuesday in The New England Journal of Medicine.

Protection against severe illness did not wane during the six weeks after the dose but researchers said more research was needed to evaluate its longer-term protection.

The study of 1.3 million people aged 60 and older analysed data from the Israeli Ministry of Health database from January 10 to March 2, when the Omicron variant was predominant.

"Rates of confirmed SARS-CoV-2 infection and severe Covid-19 were lower after a fourth dose of BNT162b2 vaccine than after only three doses. Protection against confirmed infection appeared short-lived, whereas protection against severe illness did not wane during the study period," the report said.

The US Food and Drug Administration is set to convene on Wednesday to discuss the need for additional boosters, a week after America authorised a second booster shot for people aged 50 and older amid a spread of the Omicron subvariant BA.2, Reuters reported.

Israeli President Isaac Herzog and his wife Michal receive their third coronavirus vaccine injections at Sheba Medical Centre in Ramat Gan, Israel.

Former Israeli prime minister Benjamin Netanyahu and his wife Sara receive their third doses of the Pfizer-BioNTech Covid-19 vaccine in Tel Aviv.

Israel has launched a campaign to give booster shots to people 60 years and over.

An Israeli health worker prepares to administer a third dose of the Pfizer-BioNtech vaccine at a Maccabi Health Service clinic in Jerusalem.

More than 57 per cent of the country’s 9.3 million citizens have received two doses of the Pfizer-BioNTech vaccine.

Israel is the first country to offer a third dose of a Western vaccine to its citizens on a wide scale.

Anyone over 60 who was vaccinated more than five months ago will be eligible for a third vaccine.

Neither the US nor the EU have approved coronavirus booster shots.

Israeli Prime Minister Naftali Bennett, first right from centre, said a team of expert advisers had agreed it made sense to launch the booster campaign.

Mr Bennett said the recommendation was made after 'considerable research and analysis'.

Israel said its research behind the third vaccine would be shared around the world.

The decision to offer booster shots to older citizens comes at a time of rising infections and signs the vaccine’s efficacy dwindles over time.

European health ministers have also urged the bloc's governments to back a fourth dose for people aged 60 and older.

In Asia, South Korea started giving out fourth doses of Covid vaccines in February. Singapore said a second booster dose is planned for those aged 80 and older.

Another study from Israel last month showed that older people who received a second booster of the Pfizer-BioNTech vaccine had a 78 per cent lower mortality rate than those who had only one.

Israel began offering a second booster in January.