Study: Corona virus BA.4 and BA.5 mutants evade natural and acquired immunity from full immunization

Dubai, United Arab Emirates (CNN) — Omicron’s BA.4 and BA.5 submutants appear to evade antibody responses in people who have previously had “Covid-19” and those who have been fully immunized and given a booster dose. . ., according to new data from researchers at Beth Israel Deaconess Medical Center, affiliated with Harvard Medical School.

However, the COVID-19 vaccine is still expected to provide significant protection against serious illness. Vaccine makers are working on updated doses that can produce a stronger immune response against the mutants.

And a new study, published in the “New England Journal of Medicine” on Wednesday, showed that levels of neutralizing antibodies caused by previous infection, or vaccinations, are several times lower against the BA.4 and BA submutants. 5. compared to the primary coronavirus.

“We observed a decrease in neutralizing antibody titers from vaccination and previous infection against BA.4 and BA.5 compared to previous infection against BA. with BA.1 and BA.2, three times, which is much more lower than the mutant basic Covid.”

“Our data indicate that these two new omicron submutants are likely to infect those with immunity to the vaccine and those infected with natural mutants BA.1 and BA.2,” Baruch said.

He continued: “However, vaccine immunity is likely to always provide significant protection against severe disease with BA.4 and BA.5.”

The newly published results echo the findings of other research by Columbia University scientists, in which they indicated that the BA.4 and BA.5 mutants evade antibodies in the blood of fully immunized or previously Covid-infected adults, and they warned of an increased risk of infection again.

The US Centers for Disease Control and Prevention (CDC) estimates that 94.7% of the US population age 16 and older have coronavirus antibodies that causes covid-19, through vaccination, infection, or both.

And the US agency announced in its data published on Tuesday, that the percentage of infection with mutants BA.4 and BA.5 was estimated at 35% of all new infections with “Covid-19” in the United States last week. , compared to 29% the previous week.

BA.4 and BA.5 are among the fastest-spreading variants reported to date, and are expected to dominate infections in the US, UK and other countries in Europe for the next few weeks, according to the European Center for Disease Control and Prevention. Control.

The ability of the “Covid-19” virus to mutate

The study, published in the “New England Journal of Medicine,” indicated that the researchers found that the levels of neutralizing antibodies against the “Omicron” submutants were much lower than the response against the primary coronavirus, two weeks after receiving the booster dose in 27 research participants who have previously received the series of vaccines and the booster dose of the “Pfizer/BioNtech” vaccine against Corona virus.

Neutralizing antibodies were lower by a factor of 6.4 against BA.1, a factor of 7 against BA.2, a factor of 14.1 against BA.2.12.1, and a factor of 21 against BA.4 or BA. .5.

The researchers found similar results in the 27 participants who had been previously infected with the BA.1 or BA.2 submutants, 29 days earlier, on average.

Among those with previous infections, most of them were also immune, the researchers described, with neutralizing antibody levels lower by a factor of 6.4 against BA.1, a factor of 5.8 against BA.2, a factor of 9.6 against BA.2.12.1, and a factor of 18.7 against BA.4 or BA.5.

They felt more research was needed to determine exactly what neutralizing antibody levels meant for vaccine efficacy and whether similar results would be seen among a larger group of participants.

“Our data indicates that COVID-19 still has a high ability to mutate, which increases its susceptibility to spread and increases its evasion of antibodies,” Baruch told CNN. He recommended the need for caution “in lifting the restrictions imposed and continuing to study mutants and those new subtypes of them as they appear.”

Some vaccine manufacturers have developed mutant-specific vaccines to enhance antibody responses to MERS-CoV and its subtypes of interest.

“Reinfection is hard to prevent until we have vaccines or widespread measures that limit the increase in cases,” said Pavitra Roychodry, an interim instructor in the Department of Laboratory Medicine and Pathology at the University of Washington, who was not involved in the study. which was published in the New England Journal of Medicine. Again. But the good news is that we are, I think, in a better position.” She had hoped that “these protections would provide mostly mild illnesses.”

Efforts are underway to update COVID-19 vaccines.

Moderna’s bivalent COVID-19 vaccine booster, mRNA-1273.214, elicited “strong” immune responses against the BA.4 and BA.5 omicron submutants, the company announced Wednesday.

This bivalent booster vaccine contains components of Moderna’s core COVID-19 vaccine, as well as a vaccine targeting the Omicron mutant. The company indicated that it seeks to complete the required regulatory conditions in the coming weeks, to require that the composition of its booster vaccine be updated to become mRNA-1273.214.

“In the face of the ongoing evolution of SARS-CoV-2, we strongly encourage our lead fall booster candidate mRNA-1273 and BA.5, which represent a new global public health threat.”

“We will provide this data to regulators urgently and prepare to supply the next generation of the bivalent booster starting in August, before a possible increase in SARS-CoV-2 infections due to Omicron subvariables, in early fall.” , he added.

The US Food and Drug Administration’s Advisory Committee on Vaccines and Related Biologics is meeting next week to discuss the composition of COVID-19 vaccines that can be used as boosters this fall.

Data released Wednesday by Moderna, which was not published in a peer-reviewed journal, showed that, one month after a 50-mcg dose of mRNA-1273,214 was given to boosted vaccinated people, the vaccine recorded strong neutralizing antibody responses against BA.4 and BA.5, 5.4 times higher in all participants who had previously been infected with “Covid-19”, and 6.3 times higher in the subgroup in which the participants did not had previously been infected.

These results add to data published by Moderna earlier this month showing that a 50 mcg dose of the bivalent booster elicited a stronger antibody response against Omicron than Moderna’s base vaccine.

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