A team of researchers from Seattle is raising concerns about a mutation in the COVID-19 virus that’s infecting growing numbers of people in Washington state and beyond.
The L452R mutation affects thespike proteinthat studs the virus, leading to its crown or corona shape. The spike is also responsible for sticking to and invading human cells, causing infections. Changes in the spike can potentially lead to a more potent virus.
The mutation is present in what’s called theCalifornia variant, also known asB.1.427/B.1.429, and another less common California lineage that had the distinction ofinfecting gorillas在圣地亚哥动物园野生动物园-第一个已知的大猿类冠状病毒病例。在对公共数据库的搜索中，西雅图的科学家们在全世界至少6个不同的谱系中发现了这种突变。
Sokurenko，一本书的资深作者new, not yet peer-reviewed study, suggests that this specific, small mutation could be the secret to these variants’ success in causing increasing numbers of infections.
“The emergence of these variants, it adds such a big unknown to our future,” saidCindy Liu博士乔治华盛顿大学米尔肯公共卫生学院副教授。“就我们如何应对而言，这是一个极其重要的问题。”
The California variants are currently classified as “variants under investigation” by the U.S. Centers for Disease Control and Prevention. The most serious mutants are dubbed “variants of concern.” That指定when the variant is shown to either be more easily transmitted, cause people to become sicker, render the vaccines less effective or any combination of these effects.
有证据suggesting the California variants could carry all three of these negative effects. But the research at this point is limited, and experts differ in their opinions of the relative threat.
California variants increasingly prevalent
Dr. Charles Chiu, a virologist at the University of California, San Francisco, was one of the first to identify the most common California variant. His research indicates it’s more infectious, but he recently toldthe New York Timesthat it was unclear how vaccines will perform against it.
Variants of concern include the United Kingdom variant, or B.1.17; the South African or B.1.351; and a variant from Brazil. The UK and South African variants wererecently identifiedin Washington state. The state is reporting officially only on the variants of concern.
The California variant first began infecting people in California in July, but in November the number of COVID cases caused by L452R mutants began increasing dramatically and they’ve continued to grow. Washington state has many fewer infections from these variants, but the number is rising in the state, as well.
The websiteOutbreak.info, a project tracking variants that’s run by labs at Scripps Research, has plotted the increases. The site estimates that 35% of COVID cases in California are from viruses containing the L452R mutation, and 15% of Washington state cases include it. The percentages are only rough estimates, however, and draw from available data as opposed to data selected to be precisely representative of prevalence.
An Outbreak project scientist warned against making strong conclusions about the impact of the mutation, such as whether it drove California’s case outbreak in December and January.
“Is the variant causing the surge, or is it because of the surge that the variant’s increasing?” saidKarthik Gangavarapu他是斯克里普斯大学免疫学和微生物学系的研究生。
At the same time, Gangavarapu agreed that the California variant could wind up a variant of concern.
Role of vaccines
It’s unclear how the California variant behaves against existing COVID vaccines, but the shots can be modified to better match them, experts say. The mRNA vaccines like those produced by Moderna and Pfizer are more amenable to updates than traditional vaccines, andModerna is ready to start testinga version targeting the South African variant.
Given that COVID is unlikely to be eliminated any time soon, researchers emphasized the need to stay focused on treatments for COVID patients, as well. It could make sense to tailor the approach depending on which form of the virus infects someone.
Sokurenko在这篇研究论文中的合著者包括UW的同事、Kaiser Permanente Washington、非营利性抗生素耐药性监测、分析和诊断联盟（ARMADA）以及两家生物技术公司：UW的一家名为ID Genomics的初创公司和IEH Laboratories and Consulting Group。
On Wednesday, the Washington Department of Health announced that it was boosting its ability to search for COVID variants with faster sequencing equipment that uses nano-technology being deployed at a public health lab in Shoreline. The state is currently sequencing 2% of COVID-positive cases and hopes to increase that rate to 5%.