The first case of a worrying coronavirus variant that became dominant in parts of Brazil was identified in California, in an individual in San Bernardino County, according to state and federal public health officials.
The California Department of Public Health confirmed the case on Wednesday, along with a fourth case of a South African variant, which was identified in a resident of Santa Clara County.
Variant P.1 has mutations similar to variant B.1.351 in South Africa, and both are somewhat resistant to antibodies generated by vaccines or natural infection. The P.1 variant in particular is associated with cases of reinfection in Brazil and is believed to have fueled a second wave there.
Both variants are believed to be more infectious than previous versions of the virus.
In addition, the Centers for Disease Control and Prevention has now updated two fast-spreading variants that first emerged in California for their “worrying variants” category.
All four cases of variant B.1.351 in California 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 outside the country. But the fourth case was in an individual who did not travel, which suggests that the variant is spreading in the community, county public health officials said.
“Considering national trends, we have been operating under the assumption that these variants were circulating at some level in our communities,” said Dr. Sara Cody, Santa Clara County Health Officer, in a statement. “This last case confirms that we have transmission in the community and reminds us not to let our guard down in the middle of this pandemic.”
Across the country, 27 cases of variant P.1 have been 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 infectious variant B.1.1.7 found for the first time in the United Kingdom is spreading rapidly in the United States. It accounted for about 10% of all genomic sequences that US 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 that 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 it spreads mainly 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, especially in California, where they were first detected. The two account for more than half of the cases sequenced in many counties and about 12% to 20% of cases across the country, according to the GISAID database.
Early studies, including work done outside UCSF, suggest that they are about 20% more infectious than the original virus and are also resistant to some antibodies.
Scientists believe that available vaccines still provide strong protection against both California variants and the United Kingdom variant. They may lose some effectiveness against Brazil and South Africa variants, but vaccine manufacturers are already developing reinforcements.
Erin Allday is a writer for the San Francisco Chronicle. Email: [email protected]