Israeli data shows Pfizer jab stops disease, effect on transmissions unclear

Initial data from Israel’s coronavirus vaccination campaign shows Pfizer / BioNTech vaccine protects against serious disease, but it is not yet clear whether it is slowing transmissions or indicating progress towards it. collective immunity, say experts.

The Jewish state is leading what is widely described as the world’s fastest per capita vaccination campaign, closely watched by experts around the world.

While many countries grapple with purchases, Israel has made remarkable progress since launching vaccinations in December.

So far, it has administered the first of two recommended doses of Pfizer jabs to around 35% of its population of nine million.

About 1.8 million also received the second blow, mostly those over the age of 60.

The Health Ministry announced that starting Thursday, all Israelis aged 16 and over will be able to schedule an appointment to be vaccinated, lowering the age limit from its previous minimum of 35 years.

In a statement, the ministry stressed on Wednesday that Israel’s four health service providers should still focus their efforts on immunizing people aged 50 and over, as well as Israelis confined to the house.

Israel has secured its substantial stock by paying above market price and entering into a data-sharing deal with Pfizer.

The deal says Israel, which has one of the world’s most sophisticated medical data systems, will share real-time information with Pfizer on the vaccine’s impact, including progress towards herd immunity.

Direct vs indirect protection

Ran Balicer, chairman of the Israeli national expert group on Covid-19, told AFP that it was crucial to distinguish between the two impacts of the vaccine.

The first is “the direct effect”, with vaccinated people becoming “protected against symptomatic illnesses and serious illnesses,” he said.

The second, “indirect effect,” refers to the vaccine that provides enough immunity to enough people to form an “epidemiological barrier” against transmission, he said.

Balicer, also director of innovation at Clalit, Israel’s largest health maintenance organization (HMO), said data shows the vaccine reduces serious illness, but the question of transmission remains open.

Gabi Barbash, a prominent public health scholar currently at the Weizmann Institute of Science, agreed.

“We know that vaccines decrease the incidence of serious diseases. That’s all,” he told AFP.

“We don’t know if vaccines minimize transmission.”

Phase IV

In November, Pfizer announced that Phase III trials had shown its vaccine to be 95% effective against the virus.

Given the severity of the pandemic, it received regulatory approval through an expedited testing process, which made Israel’s more comprehensive data even more valuable.

The country’s Maccabi Research and Innovation Institute, linked to an HMO of the same name, published an article this week that it described as “the first and largest Phase IV study into the efficacy of the vaccine. (Pfizer-BioNTech) “.

Clalit and Maccabi are two of Israel’s four HMOs, which collectively provide health care to the entire population.

HMOs are directly responsible for vaccinations and for collecting data on their impact.

Maccabi compared the incidence of Covid-19 within 12 days of the first Pfizer vaccine to the incidence 13 to 24 days after the vaccine.

He found a 51 percent reduction in the incidence of laboratory-confirmed infections during this latter period.

“Two weeks after the first dose, you see a significant reduction in the infection, but it is not complete,” Gabriel Chodick, co-author of the Maccabi report, told AFP.

Additionally, Israel only tests those who show symptoms of coronavirus, not a random sample of the entire vaccinated population.

It therefore does not have complete data on the number of vaccinated people carrying the virus without symptoms.

Two shots

Pfizer recommends giving its vaccine in two doses, three weeks apart.

Israel has enough stocks to follow these recommendations, which means it does not have data on whether the protective effect of a single shot increases after 24 days in the absence of a second shot.

Maccabi also released preliminary data on the impact of the second blow.

It showed that out of 248,000 people studied a week after receiving their second injection, only 66 mild coronavirus infections were recorded.

Although these numbers indicate near total protection, Maccabi stressed that the data had not been fully analyzed.

Despite its vaccination campaign, Israel continued to record daily records above 5,000, despite a national lockdown in place since December 27.

But respect and enforcement of the lockdown has been uneven, especially among ultra-Orthodox Jews who have consistently flouted public safety rules throughout the pandemic.

“If you look at the number of new positive corona cases identified per day, it hasn’t gone down for a month and a half,” Barbash said.

“So is it because the lockdown is not a (real) lockdown, or is it because the vaccine doesn’t minimize transmission? No one can tell.”

---

---

© 2021 AFP