A small Israeli study indicates that some of the new variants of coronavirus may put people who have been vaccinated at a higher risk of discovered infections, although US health officials have questioned some of the wording used in the preliminary research.
These types of cases are called “discovered infections”, which occur when someone who has completed their COVID-19 vaccination later becomes ill with the virus.
The prepress, which was released Friday and was not evaluated by colleagues, gained attention over the weekend after it said that variant B.1.351 was more likely to infect people in Israel who had been vaccinated with PFE from Pfizer Inc.
COVID-19 vaccine compared to other strains of the virus.
There are several documented variants of concern, including B.1.351, first identified in South Africa; B.1.1.7, first detected in the United Kingdom; and P.1 from Brazil, which are thought to be easy to transmit.
The researchers identified eight cases of discovered infections caused by variant B.1.351 and 134 cases of variant B.1.1.7 out of the approximately 400 people included in the study who tested positive for the virus during or after the vaccination period. . Strangely, the control group of unvaccinated people had only one case caused by B.1.351.
“Our results show low efficiency against [South African] variant only in a short period of time (7-13 days after the second dose), because all the cases of discovery that I saw were in this time interval “, said Adi Stern, professor at Tel Aviv University and one of the co-authors, in an e-mail. “However, once again the warning is that the size of our sample is small and this requires further research.”
When asked about the study, federal health officials downplayed the accuracy of the findings on Monday.
“Pre-printing was confusing at one point,” said Dr. Anthony Fauci, President Joe Biden’s chief medical officer, during a White House briefing. “It simply came to our notice then [B.1.]351 if, in fact, you have been vaccinated against mRNA. It was not the case. If you were infected with something, you would be infected with the more difficult version, which was 351. That does not mean that you are more likely to receive it. ”
Pfizer asked the authors questions about the study.
What we know so far about vaccines and variants
Fauci said that clinical data so far indicate mRNA vaccines developed by Pfizer and BioNTech SE BNTX,
as well as Moderna Inc. MRNA,
still provides protection against B.1.1.7, but the vaccine is thought to be less effective against variant B.1.351, which is a less common strain of the virus at this time, at least in the United States.
Both mRNA vaccines had very high efficacy rates in phase 3 clinical trials, each reporting rates of approximately 95%, although the studies were conducted last fall, before two of these new variants were detected. The real-world effectiveness rate for both vaccines is believed to be closer to 89%, according to at least one prepress study published by the Mayo Clinic in February, but which is still considered a very strong rate of protection against the virus.
Here’s what we know – and don’t know – about “discovered infections”
While taking COVID-19 photos can dramatically reduce the chance of someone becoming infected with the virus, infections are still possible for vaccinated people, especially with these new, more infectious variants of the coronavirus circulating around the world.
Last month, Moderna said it would begin clinical trials, in partnership with the National Institutes of Health, on a vaccine specifically aimed at protecting against variant B.1.351. Pfizer is also conducting studies for a booster vaccine and a new vaccine specifically targeting the South African version.
“What we know when these revolutionary infections occur is that they tend to appear with fewer symptoms, fewer viruses. [and] less transmissible virus, ”said Rochelle Walensky, director of the Centers for Disease Control and Prevention, during the same briefing. “We are still learning about the transmissibility of this virus in the context of these revolutionary infections.”
Revolutionary infections can also occur if immunity drops, the blow is damaged due to a storage problem, or if someone’s age or medications limit their immune response, Fauci added.
That is why the Americans pay special attention to Israel’s vaccination campaign
Of all the countries in the world with vaccination campaigns, Israel has vaccinated the largest percentage of its population. About 53 percent of Israelis have been fully vaccinated since Sunday, according to a government dashboard. In comparison, the US has vaccinated about 22% of its population, although much higher, since Monday, according to the CDC.
The Pfizer vaccine is the predominant shot used in the Israeli campaign, so countries that rely on the drugmaker’s vaccine are also curious to see what real-world data is coming out of Israel right now, even though there are significant differences between nations’ immunization protocols.
The Israeli study also found that variant B.1.1.7 (UK) is the most dominant form of the virus in Israel (as it is in the US), although strain B.1.351 (South Africa) was less of 1% of the cases included in the research.
“There may be higher rates of vaccine detection with B.1.351, but it is possible that (a) the efficacy of the vaccine, combined with the non-pharmaceutical interventions adopted, remains sufficient to prevent its spread and / or (b) B.1.1 .7
exceeds B.1.351, possibly due to its high transmission rate “, the researchers concluded.