A new study by a Japanese research team has found that the new Mu variant of the new coronavirus is more than seven times more resistant to antibodies created by vaccines than the original strain of the virus.
Despite the increase in resistance, “the Mu variant does not make vaccines ineffective and does not require new antivirus measures at the individual level,” said Kei Sato, an associate professor of virology at the Institute of Medical Sciences (IMS). the University of Tokyo) and a member of the team.
“(But) we found that the variant is the most antibody-resistant among the previously detected virus strains,” he added. “It is crucial to identify what types of variants are widespread. This will require an expansion of the ability to perform genome scans, which can provide detailed genetic information about the virus. “
The World Health Organization has added the Mu variant, first detected in Colombia, to the list of mutated strains of the virus that it monitors and monitors its spread.
In the study, a team of IMS researchers from the University of Tokyo and other institutions connected a spike protein, which protrudes from the surface of the virus and infects human cells. on the surface of another virus that can be handled more easily than the actual coronavirus.
The researchers repeated the process to generate “pseudoviruses” that contained tip proteins from several mutated strains of the virus and tested the extent to which neutralizing antibodies collected from people inoculated against COVID-19 could prevent pseudoviruses from entering cells. cells prepared for study.
The team’s results showed that the Mu variant reduced the effectiveness of antibodies produced from vaccines than other strains of the virus. But part of the immunity acquired through inoculations works by mechanisms other than antibodies.
On 30 August, the WHO designated the Mu variant as a variant of interest. Subsequently, the health ministry announced that the variant was detected in two travelers from abroad at the airport quarantine checks in Japan.
The Delta variant, which is being scammed around the world, is designated as a variant of concern, a notch above the interest category.
The team released its findings on Sept. 7, before the study was peer-reviewed. It can be seen in: (https://www.biorxiv.org/content/10.1101/2021.09.06.459005v1.full)