By Michael Erman
February 17 (Reuters) – A laboratory study suggests that the South African variant of the coronavirus could reduce antibody protection against the Pfizer Inc / BioNTech SE vaccine by two-thirds, and it is not clear whether the shot will be effective against the mutation. be not, the companies said. Wednesday.
The study found that the vaccine is still able to neutralize the virus, and there is still no evidence from trials in humans that the variant reduces the protection of the vaccine, the companies said.
Yet they make investments and talk to regulators about developing an updated version of their mRNA vaccine or an abooster shot, if necessary.
For the study, scientists from the companies and the University of Texas Medical Branch (UTMB) developed an engineering virus that contained the same mutations that were at the peak portion of the highly contagious coronavirus variant first discovered in South Africa, known as B .1.351. The peak, which is used by the virus to enter human cells, is the primary target of many COVID-19 vaccines.
Researchers tested the engineered virus against blood taken from people who received the vaccine, and found that the level of neutralizing antibodies decreased by two-thirds, compared to its effect on the most common version of the virus found in US trials. .
Their findings were published in the New England Journal of Medicine (NEJM).
Because there is no established measure yet to determine what level of antibodies are needed to protect the virus, it is unclear whether reducing two-thirds will make the vaccine ineffective against spreading the world.
However, UTMB professor and co-author of the study, Pei-Yong Shisaid, believes the Pfizer vaccine is likely to be protective against the variant.
“We do not know what the minimum neutralizing number is. Do not have the cut-off point,” he said.
This is because both the Pfizer / BioNTech vaccine and a similar inclusion of Moderna Inc in clinical trials provide tremendous protection after a single dose with an antibody that responds to the lower levels caused by the South African variant in the laboratory study.
Even if the variant in question significantly reduces its effectiveness, the vaccine should still help protect against serious illness and death. Health experts said it was the most important factor in preventing protracted healthcare systems from being overwhelmed.
More work is needed to understand whether the vaccine works against the South African variant, Shi said, including clinical trials and the development of correlates of protection – the criteria for determining which antibody tests are protective.
Pfizer and BioNTech said they are doing similar lab work to understand if their vaccine is effective against another variant first found in Brazil.
Moderna published a correspondence in NEJM on Wednesday with similar data that was revealed earlier earlier and that shows the asylum-like decrease in antibody levels compared to the South African variant.
Moderna also said that the actual effectiveness of the vaccine against the South African variant has yet to be determined. The company said earlier that it believes the vaccine will work against the variant (reporting by Michael Erman; additional reporting by Julie Steenhuysen in Chicago; editing by Bill Berkrot)