In a study that has not yet been peer reviewed and had been done on mice, Japanese investigators pinpoint Delta variant mutations that might be able to evade COVID-19 vaccine antibodies.
The Delta variant could potentially mutate into another iteration that would give it the ability to avoid the antibodies contained in COVID-19 vaccines, according to a study that has not yet been peer reviewed and which had been done on mice. The study appears on bioRxiv, a site that shares preliminary scientific data.
Investigators at Osaka University in Japan argue that 4 Delta mutations—K417N, N439K, E484K and N501Y—could help Delta escape vaccine antibodies, though their conclusions were reached through experiments on mice.
“Although Pfizer-BioNTech BNT162b2-immune sera neutralized the Delta variant, when four common mutations were introduced into the receptor binding domain (RBD) of the Delta variant (Delta 4+), some BNT162b2-immune sera lost neutralizing activity and enhanced the infectivity,” the study states.
Thirty-six cases around the world involve patients had two of the mutations to the Delta variant. The study states that “sera of mice immunized by Delta spike, but not wild-type spike, consistently neutralized the Delta 4+ variant without enhancing infectivity. Given the fact that a Delta variant with three similar RBD mutations has already emerged according to the GISAID database, it is necessary to develop vaccines that protect against such complete breakthrough variants.”
Although the data are preliminary, Kevin Kavanagh, MD, a member of Infection Control Today®’s Editorial Advisory Board, says that the findings warrant attention. “This report is an example of gain of function research using a pseudo-virus which is extremely beneficial,” Kavanagh tells ICT®. “The research reported that the Delta virus is one mutation away from fully escaping the vaccine. It is possible that those infected with the Delta variant may have a degree of immunity, but those vaccinated or who had COVID-19 with a previous variant will be at high risk for a significant reinfection.”
Pseudo-viruses such as the Delta 4+ iteration that the investigators manufactured in the lab are considered harmless and cannot self-replicate. However, the virus could not be stopped by antibodies made from the Pfizer/BioNTeck vaccine in the lab. The title of the study is “the SARS-CoV-2 Delta variant is poised to acquire complete resistance to wild-type spike vaccines.” It’s important that new or tweaked COVID-19 vaccines are manufactured as quickly as the coronavirus mutates, the Osaka University investigators said.
Apparently, Pfizer CEO Albert Bourla couldn’t agree more. Bourla told Fox News earlier this week that Pfizer keeps a close eye on variants that might escape vaccines. “Every time that a variant appears in the world, our scientists are getting their hands around it,” Bourla said. “And they are researching to see if this variant can escape the protection of our vaccine.” He added that “we haven’t identified any yet, but we believe that it is likely that one day, one of them will emerge.”