First case of disturbing variant of Brazil’s coronavirus discovered in California

The P.1 variant has mutations similar to the B.1.351 variant from South Africa, and both are somewhat resistant to antibodies generated by vaccines or natural infection. Variant P.1 in particular is associated with cases of reinfection in Brazil and would have fueled a second wave there.

Both variants are also believed to be more infectious than earlier versions of the virus.

In addition, the Centers for Disease Control and Prevention has now upgraded two rapidly spreading variants that first appeared in California under its “variants of concern” category.

The four California cases of the B.1.351 variant were found in the Bay Area: two in Alameda County and two in Santa Clara County. The previous three cases were found in people who had recently traveled out of the country. But the fourth case involved a person who had not traveled, suggesting that the variant is spreading in the community, county public health officials said.

“Given national trends, we have operated under the assumption that these variants are circulating at some level in our communities,” Santa Clara County health officer Dr. Sara Cody said in a statement. “This latest case confirms that we have community transmission and reminds us not to let our guard down in the midst of this pandemic.”

Nationwide, 27 cases of variant P.1 were reported in 12 states and 142 cases of variant B.1.351 in 25 states. According to GISAID, an international database of genomic sequences used to identify and track coronavirus mutations, the two variants account for less than 1% of all cases in the United States.

Meanwhile, the highly contagious B.1.1.7 variant first found in the UK is spreading rapidly in the US. It accounted for about 10% of all genomic sequences that U.S. labs have reported to the database in the past four weeks, down from just 4% a month ago.

More than 4,600 cases of B.1.1.7 have been reported in all 50 states, according to the CDC. The variant is expected to become dominant in parts of the United States by the end of this month or early April, CDC officials said.

Santa Clara County officials said on Wednesday they had identified 15 cases of B.1.1.7. Cases have also been reported in Alameda and Contra Costa counties in the Bay Area, although they are mainly spreading in southern California.

The two additional variants, B.1.427 and B.1.429, which were added to the CDC’s list of variants of concern this week are also spreading rapidly, mainly in California, where they were first detected. The two account for more than half of sequenced cases in many counties and about 12-20% of cases nationwide, according to the GISAID database.

Early studies, including work done from UCSF, suggest that they are around 20% more infectious than the original virus and are resistant to certain antibodies as well.

Scientists believe that the available vaccines still offer strong protection against the two California variants and the UK variant. They may lose some efficacy against variants from Brazil and South Africa, but vaccine makers are already developing boosters.