Two days after the Los Angeles Public Health Department announced that the much-talked-about U.K. variant of Covid-19, known as B.1.1.7, had been identified in the region, the California Department of Public Health revealed that another lesser-known strain had been circulating in the county as well.
Known as L452R, the newly-announced arrival was first identified in Denmark in March of last year. It showed up in California as early as May 2020.
According to Dr. Charles Chiu, a virologist and professor of laboratory medicine at UCSF who has been genetically sequencing test samples to identify new variants, L452R grew from about 3.8% of the samples he tested in late November 2020 through early December to more than 25.2% in late December of that year through early January 2021.
The L452R variant affects the spike protein of the virus, so there’s a chance the currently-developed vaccines will be less effective against it, said Chiu. The current vaccines being administered in the United States were designed to give people immunity by inhibiting the virus’s spike protein.
Santa Clara County has sequenced a large number of positive specimens collected from community testing sites and outbreaks in the county. The L452R variant was present in specimens from the community and from several large outbreaks, including outbreaks where very high numbers of people exposed contracted the virus.
An article on Cell.com says variant 452R has “decreased sensitivity to neutralizing mAbs (monoclonal antibodies),” which are used in the currently-approved vaccines to inhibit connections between spike proteins of the virus and infected cells.
Chiu said very early studies of the L452R spike protein mutation indicate it’s less susceptible to those neutralizing antibodies.
“This variant was identified in several large outbreaks in our county,” according to Santa Clara County Health Officer Dr. Sara Cody. She called that correlation “a red flag and must be investigated further.”
According to the California Department of Public Health, Santa Clara County has sequenced a large number of positive specimens collected from community testing sites and outbreaks in the county. The L452R was present in specimens from the community and from several large outbreaks, including outbreaks where very high numbers of people exposed contracted the virus.
The new variant has also been detected in Los Angeles, Mono, Monterey, Orange, Riverside, San Francisco, San Bernardino, San Diego, San Luis Obispo, Humboldt and Lake counties. Because genomic sequencing is sparse across the state or country, it is currently unknown how prevalent L452 is statewide, nationally or globally.
“This variant carries three mutations, including L452R, in the spike protein, which the virus uses to attach to and enter cells, and is the target of the two vaccines that are currently available in the United States,” said Dr. Chiu.
And there may be another issue with one of those vaccines.
California’s State Epidemiologist Dr. Erica Pan said on Sunday that a “higher than usual” number of people had apparent allergic reactions to a batch of Moderna’s vaccine at a San Diego-area clinic.
“Out of an extreme abundance of caution,” Pan recommended that clinics should stop using doses from that specific batch until federal, state and company officials investigate it.
California has about 330,000 doses from the lot in question. That equates to approximately 10% of all vaccine distributed to date across the state.
And there is still the potentially more contagious the U.K. variant, B.1.1.7. Los Angeles Public Health officials confirmed the first case of that strain over the weekend.
Though Saturday may mark the strain’s first identified appearance in Los Angeles County, health officials said in recent weeks that it was very likely already circulating there. B.1.1.7 had previously made its way through San Diego and San Bernardino Counties. Before that, the strain had been found in Colorado, marking the first U.S. case of the Covid-19 variant.
The CDC warns that the presence of B.1.1.7 can mark a new phase of “exponential growth” in total Covid-19 cases.
While vaccine rollout may be a glimmer of hope amid the soaring numbers and the appearance of the new B.1.1.7 variant, officials warn that L.A. County may see darker days.
“Current projections by the experts predict that if left unchecked, this variant could dominate locally by March,” Los Angeles Public Health director Barbara Ferrer said on Friday. We can now add to that the potential threat of a vaccine-resistant strain in L452R, as well.
As a result, L.A. County officials have been discussing the possibility of new shutdowns and restrictions.