Scientists at Stanford University last week confirmed the nation’s first case of a “double mutant” variant of the Chinese communist virus (COVID-19). It now appears that a small number of people may have been infected with the variant, which contains two of the original mutations L452R and E484Q that have hit the world. Experts fear that this new variant may increase the risk of transmission and allow the virus to escape the human immune system.
The variant was identified by the Stanford University Health Clinic Virus Laboratory, KRON reported. The “L452R+E484Q double mutation” variant of the virus was first discovered in India. Stanford scientists believe that the case they identified is the first in the United States.
Stanford researchers have begun screening hundreds of samples of the virus collected from Bay Area residents and plan to increase the number of collections significantly in the coming days. In addition, they have begun sequencing the entire viral genome to identify new mutations in key viral proteins.
It is too early to say whether or how these variants will affect the CCP virus outbreak, but it is important to monitor their evolution and spread, said Benjamin Pinsky, associate professor of pathology and infectious diseases at Stanford School of Medicine. “Our surveillance tests are specifically designed to allow large-scale screening of virus samples to identify specific strains that are spreading in the Bay Area and throughout California.”
Double Mutations Increase in Indian Samples
On March 24, the Indian Ministry of Health announced that an increased percentage of samples containing the L452R and E484Q mutations were found in samples collected in the Indian state of Maharashtra, which accounts for 60 percent of all active cases in India, compared to last December.
The latest samples were genomically sequenced by 10 national laboratories under the Indian Ministry of Health. Shahid Jameel, an Indian virologist, said the double mutation in a key region of the virus’ stinger protein may increase the risk of virus transmission and allow the virus to escape the immune system.
Mutations in the stinger protein, a part of the virus that is used to penetrate human cells, could make the virus more infectious or help it escape capture and neutralization by antibodies. This also means that the new variant could put already recovered COVID-19 ex-infected people at an increased risk of being reinfected.
The Indian Ministry of Health also said in a statement that this double mutation has the potential to increase the immune escape capacity of the virus as well as its infectivity. However, the department’s statement also said that the number of tests available is still too limited to establish a link between this new double mutation and the recent surge of infections in India.
L452R mutation is the primary mutation in the California variant
The L452R mutation is also the major mutation in the California native variant CAL.20C, which is thought to be associated with the massive outbreak of the CCP virus outbreak in California a while ago.
In a study released in January, Cedars-Sinai said CAL.20C was found in one-third of cases in Los Angeles County and one-fourth of cases in Southern California. in addition, Northern California health officials also said in January that recent large outbreaks of infection in the Bay Area have been linked to L452R.
As previously reported by sciencemag.org, researchers analyzed data from the medical records of 324 COVID-19 patients at the University of California, San Francisco (UCSF) medical facility and found that patients carrying the mutated strain were 4.8 times more likely to be admitted to the intensive care unit (ICU) than other COVID-19 patients and had a mortality rate more than 11 times higher.
In addition, laboratory studies showed that B.1.429 (containing the L452R, D614G, S13I, and W152C mutations) in the CAL.20C series, also affects the effectiveness of the antibodies. Using antibodies from the sera of recovered individuals to neutralize B.1.429 and the original COVID-19 virus, respectively, the effectiveness of neutralizing B.1.429 was found to be four times lower, while the effectiveness of neutralizing B.1.429 was reduced by a factor of two with antibodies from the blood of those who had received the Pfizer or Modena vaccine. The investigators concluded that this ability to diminish effectiveness, while not very strong, is significant.
E484Q mutation resembles South African and Brazilian variants
The other important of the double mutations, the E484Q mutation, is thought to be similar to the E484K mutation, the main mutation in the South African and Brazilian variants. The main effect of the E484K mutation is that it can change the shape of the stinging protein on the outside of the virus, making it difficult for antibodies to recognize it, thus facilitating the virus to hide and avoid the immune system.
Cases of variant viruses continue to increase across the United States
According to the Centers for Disease Control and Prevention (CDC), as of April 6, more than 16,275 cases of the British B.1.1.7 variant of the virus have been identified in 52 states nationwide; 386 cases of the South African B.1.351 variant have been identified in 36 states; and 356 cases of the Brazilian P.1 variant have been identified in 25 states.
California had 873, 10 and 34 cases of the British variant, the South African variant and the Brazilian variant, respectively.
According to the CDC, among the effects on the neutralization of monoclonal antibodies to the U.S. Food and Drug Administration (FDA) Emergency Use Authorization (EUA), the British variant virus had the least weakening effect, the Brazilian variant and the South African variant had a moderate weakening effect; the B.1.427 and B.1.429 series, the California native variant, had a significant weakening effect on the neutralization of some EUA antibodies.
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