Pfizer booster shot could offer protection for 9-10 months — initial data

Leaked research conducted by Israeli hospital indicates that third shot yields more antibodies, and that these antibodies are also better at preventing disease

A medic from Israel's Magen David Adom emergency service administers a booster shot of the coronavirus vaccine to a woman in Tel Aviv, Israel, Aug. 14, 2021 (AP Photo/Tsafrir Abayov)
A medic from Israel's Magen David Adom emergency service administers a booster shot of the coronavirus vaccine to a woman in Tel Aviv, Israel, Aug. 14, 2021 (AP Photo/Tsafrir Abayov)

Pfizer’s booster COVID-19 shot is effective for 9 – 10 months and maybe even longer, according to preliminary data from Israeli research leaked to Channel 12 news on Sunday.

The network said initial results from a study on antibody levels being conducted by the Tel Hashomer Hospital are set to be made public in 2 – 4 weeks, and will show that the third shot offers different, apparently improved, protection from the first two doses.

The booster shot yields more antibodies, and the antibodies are also better at preventing the disease, the channel quoted people involved with the study as saying.

By analyzing the antibody levels, researchers have concluded that the third shot could be effective for 9 – 10 months, or even longer, the researchers predicted.

No details were released on the scope or methodology of the Tel Hashomer study.

Israel began its mass booster campaign in August after finding that the protection offered by its initial two-dose vaccine campaign began wearing off after some five months.

The latest research follows a large-scale Israeli study published last month that showed that a third booster shot was 92% effective in preventing serious illness compared to those who received only two doses of the Pfizer-BioNTech coronavirus vaccine.

A medic holds up a vial of the Pfizer-BioNTech COVID-19 coronavirus vaccine at a vaccination centre at the Atid al-Najah High School for the Sciences at the city of Taibeh in northern Israel on August 19, 2021. (JACK GUEZ / AFP)

The study conducted by Israel’s largest HMO Clalit Health Services, with funding from Harvard Medical School, was published in the Lancet medical journal based on a study of 728,321 people who received the third shot compared to a control group of a similar number who received only two shots at least five months before.

According to the report the third dose of 93% effective at preventing admission to the hospital, with the health service recording 231 instances of hospitalization for the two-dose group, compared to 29 for those who got a booster shot.

Similarly, the rate stood at 92% for severe disease with 157 cases in the control group compared to 17 among those in the third shot category.

The study also found the booster shot was 81% effective in preventing COVID-related deaths, with just seven recorded among those who got the booster shot compared to 44 deaths for those without.

The study period was July 30, 2020, to September 23, 202 and participants had a median age of 51 years old. Israel has almost exclusively used the Pfizer shot.

Both groups reported significantly lower numbers of hospitalizations and deaths than those who were not vaccinated at all.

“The results demonstrate in a very convincing way that the third dose of the vaccine is extremely efficient,” said Ran Balicer, Clalit’s chief innovation officer.

Israel was the first country to widely adopt the booster and the end of Israel’s fourth wave has been credited at least in part to its booster vaccine campaign, which began among those over 65 in August and was quickly rolled out to the rest of the population. As of Sunday, almost 4 million Israelis — more than 42% of the total population — have received a third dose of the COVID vaccine. Close to 67% of the total population has received at least one shot.

Around 650,000 people who are eligible for vaccines have not received any of the shots, while about 1.1 million Israelis eligible for the booster have yet to receive it.

Since then the US and other countries have followed suit, although some have approved the booster only for the elderly or those with preexisting conditions.

US President Joe Biden receives a COVID-19 booster shot during an event in the South Court Auditorium on the White House campus, Monday, Sept. 27, 2021, in Washington. (AP Photo/Evan Vucci)

The booster shots have been widely credited with helping Israel overcome a fourth wave of the virus.

The number of active COVID-19 cases in Israel has dropped to 5,984 after being above 10,000 for over three months and after passing 90,000 in early September, according to figures released on Sunday by the Health Ministry.

The data also showed 194 new cases were confirmed on Saturday, down from between 5,000 and 6,000 daily almost two months ago. There were 167 people hospitalized in a serious condition and the death toll stood at 8,122.

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