As of this writing, the R.1 variant is not listed on the CDC’s list of variants of concern or interest. However, the CDC report notes that the variant has many unique mutations of importance, some of which show evidence of increased transmissibility of the virus and increased resistance to antibodies.
Former Harvard Medical School professor and infectious diseases expert Dr. William A. Haseltine still believes that the R.1 strain should be monitored. “It has established a foothold in both Japan and the United States,” Dr. Haseltine wrote in an article for Forbes. “In addition to several mutations notably in the spike and nucleocapsid protein in common with variants of concern, R.1 has a set of unique mutations that may confer an additional advantage in transmission, replication, and immune suppression.”
Despite some breakthrough cases, vaccines are still associated with decreased transmissibility. According to the CDC report, vaccinated nursing home residents were 87% less likely than unvaccinated patients to develop symptoms. The R.1 variant is still the most prevalent strain in America, with more than 10,000 cases reported (via Forbes).