In early January 2021, travelers returning to Tokyo, Japan, from Amazonas, Brazil, were screened for COVID-19 at the airport. A few days later, the National Institute of Infectious Disease of Japan announced that the travelers had returned with a new variant of the SARS-CoV-2 virus.
That variant, known as gamma, or P.1, led to a deadly surge in COVID-19 cases in Brazil this spring, and has now spread across the world. More than 200 cases have been detected in Wisconsin. Whether current vaccines are as effective against the gamma variant remains unknown.
In a new study using variant virus recovered from one of the original travelers, researchers in the U.S. and Japan have found that vaccination with an mRNA vaccine induces antibody responses that would protect humans from infection with the gamma/P.1 variant. Hamsters previously infected with the virus strains first circulating in early 2020 were also protected from infection with the gamma variant nine months later.
The findings, the researchers say, suggest that previous SARS-CoV-2 infection and vaccines that are based on earlier strains of the virus still provide protection against infection with gamma. The study published in the Proceedings of the National Academy of Sciences on June 17, 2021.