A small Israeli study indicates that some of the new variants of coronavirus may pose a higher risk of advanced infections in vaccinated people, although U.S. health officials questioned some of the wording used in the preliminary investigation.
Such cases are called “advanced infections,” which occur when someone who has completed the COVID-19 vaccination becomes ill after the virus.
The prepress, which was released on Friday and has not been peer-reviewed, drew attention over the weekend after saying that variant B.1.351 was more likely to infect people in Israel who had been vaccinated with PFE from Pfizer Inc.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 Brazil’s P.1, which is believed to be easily transmissible.
The researchers identified eight cases of advanced infections caused by variant B.1.351 and 134 cases of variant B.1.1.7 of the approximately 400 people included in the study who had tested positive for the virus during or after the study period. vaccination. The unvaccinated control group had, strangely, only one case caused by B.1.351.
“Our results show a reduced effectiveness against the [South African] varying only in a short period of time (7-13 days after the second dose), as all the advanced cases we saw were found in this period of time, ”said Adi Stern, a University professor of Tel Aviv and one of the co-authors in an email. “However, once again, the caveat is that the size of our sample is small and this requires further research.”
When asked about the study, federal health officials on Monday downplayed the accuracy of the findings.
“This prepress, so to speak, was as confusing as you could be,” Dr. Anthony Fauci, President Joe Biden’s chief medical adviser, told reporters during a White House briefing. “It looked like you were more likely to get the [B.1.]351 if, in fact, you were vaccinated against mRNA. It was not like that. If I infected you with something, I would infect you with the most difficult variant, which was 351. That doesn’t mean you have a better chance of getting it.
Pfizer addressed questions about the study to the authors.
What we know so far about vaccines and variants
Fauci said that so far clinical data indicate mRNA vaccines developed by Pfizer and BioNTech SE BNTX,
as well as Modern Inc. MRNA,
they still offer protection against B.1.1.7, but the effectiveness of the vaccine is believed to decrease against variant B.1.351, which is a less common strain of the virus at this time, at least in the US
Both mRNA vaccines had very high efficacy rates in the phase 3 clinical trials, with an information rate of approximately 95%, although the trials were conducted last fall, before they had been administered. detected two of these new variants. The real-world efficacy rate of these two 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 protection rate against virus.
This is what we know (and don’t know) about “advanced infections”
While receiving shots of COVID-19 can drastically decrease the chance of someone becoming infected with the virus, advanced infections are still possible for vaccinated people, especially with these new, more infectious variants of the coronavirus circulating around the world.
Moderna said last month that it will begin clinical trials, in collaboration with the National Institutes of Health, on a vaccine that specifically aims to protect against variant B.1.351. Pfizer is also conducting trials for a booster shot and a new vaccine aimed specifically at the South African variant.
“What we know when these advanced infections occur is that they usually occur with fewer symptoms, fewer viruses, [and] less transmissible virus, “Dr. Rochelle Walensky, director of the Centers for Disease Control and Prevention, said Monday.” We are still learning about the transmissibility of this virus in the context of these advanced infections. “
Fauci can also produce advanced infections if immunity decreases, the shot is damaged due to a storage problem, or if someone’s age or medications limit their immune response.
That’s why Americans pay so much attention to Israel’s vaccination campaign
Of all the countries in the world with vaccination campaigns, Israel has vaccinated the highest percentage of residents. About 53% of people in Israel have been fully vaccinated as of Sunday, according to a government board. In comparison, the United States has vaccinated about 22% of its population, though much larger, as of Monday, according to the CDC.
The Pfizer vaccine is the predominant feature used in the Israeli campaign, and therefore countries that also rely on this drug maker’s vaccine are curious to see what real-world data is coming out of Israel. right now, although there are significant differences between nations’ vaccination protocols.
The Israeli study also found that variant B.1.1.7 (UK) is the most dominant form of the virus in Israel (as in the United States), although strain B.1.351 (South Africa) represented less than 1% of the cases included in the investigation.
“There may be higher rates of vaccine progression with B.1.351, but it is possible that (a) the efficacy of the vaccine together with enacted non-pharmaceutical interventions will be sufficient to prevent its spread and / or (b ) B.1.1.7
exceeds the B.1.351 competition, possibly due to its high transmission speed, “the researchers concluded.