The Paper's reporter He Liping
Driven by the new mutant strain BA.2.12.1 in Omicron, New York, located in the northeastern United States, is becoming a hotspot for the outbreak. The number of cases in California, located at the western gateway to the United States, has also begun to surge.
According to the CDC, some early evidence in the United States suggests that BA.2.12.1 spreads faster than the Olmikeron variant. Omikejong is considered the most contagious strain of the NEW CORONAVIRUS mutation to date, and BA.2.12.1 is the fastest spreading of many Omiljung variants.
BA.2.12.1 is the next generation of the BA.2 variant strain. BA.2 has at least 30% higher transmission than BA.1. According to CNN, the spread of BA.2.12.1 is estimated to be 23% to 27% higher than its predecessor BA.2.
According to the latest surveillance data from the CDC of the US Centers for Disease Control and Prevention, the BA.2.12.1 variant has accounted for 58% of the proportion in New York and New Jersey. In the United States, the BA.2.12.1 variant has also accounted for 28.2%, which is a sharp increase of 48.4% from the previous 19%.
New York is the gateway to the United States and is the busiest area for U.S. passenger flow. Dr. Deborah Birx, a former White House COVID-19 response coordinator, said in an interview with CBS on May 1 local time, "We should now prepare for a possible surge in cases in the southern United States this summer." A similar scenario appeared in the summer of 2020 and again in the summer of 2021."
Driven by the new mutant strain, the number of new coronavirus infections in the United States has entered an upward period. According to the latest weekly report released by the CDC, as of April 27, 2022, the 7-day moving average of new cases in the United States was 53,133 cases per day, an increase of 25.2% from the previous week's 7-day moving average of 42,427 cases. The average number of admissions in the last 7 days was 1889, up 18.5% from 1594 in the previous 7 days. The positive detection rate in the United States rose to 6.1%, up 17.3% from 5.2% in the previous seven days.
According to CDC monitoring, the Omikeron lineage accounts for 100% of the NEW CORONAVIRUS variant strains in the United States. The following versions of the Omicron popular in the United States are: B.1.1.529 lineage (including BA.1, BA.3, BA.4, and BA.5), BA.1.1**, BA.2, and BA.2.12.1. The current dominant Ometchon genealogy in the United States is BA.2. The share of BA.2 in the U.S. is expected to be 68.5 percent, compared to 74 percent previously. The national share of BA.2.12.1 is expected to be 28.2%, up 48.4 percent from the previous 19.0 percent. BA.1.1 is expected at 2.8 per cent and B.1.1.529 (BA.1, BA.3, BA.4 and BA.5) is expected to be 0.2 per cent.
California health officials also said the Omikejong variant BA.2.12.1 is climbing rapidly in California and could account for half of new cases "within a few days." BA.2.12.1 is more contagious than the previous mutant strain. Since the beginning of April, COVID-19 cases in California have increased by about 70 percent, while cases in the Bay Area have increased by 155 percent over the same period. Health experts believe that the recent increase is mainly due to the more contagious variants that are now prevalent.
The surge in reported cases in the Bay Area is more pronounced than in much of california, but the reasons are unclear. As of last week, the Bay Area reported about 23 cases per 100,000 residents a day, compared with 14 cases per 100,000 people across California.
There is currently no evidence that BA.2.12.1 causes more severe symptoms than the various sub-variants of the original Omikejun strain.
Scientists use genome sequencing techniques to identify the COVID-19 variant strain. By analyzing the similarities and differences between these sequences, scientists can track the prevalence of the mutated strain and monitor changes in the genetic code of the new coronavirus variant strain. This information can give people a better understanding of how variation affects public health.
Genes in the coronavirus genome contain instructions for building the virus. For example, the brown part of the picture has genetic instructions for building spike proteins, which are the "keys" for the new coronavirus to enter human cells. Mutations in the spike protein may affect viral transmission and immune escape. Therefore, scientists pay close attention to mutations in the part of the new coronavirus spike protein. BA.2.12.1 has attracted much attention because of the mutation at the L452Q point on its spike protein. L452 is the key mutation point of the Delta variant strain, which gives Delta a transmissibility advantage and immune escape advantage, which is not available to the original Omiljun strain.
Notably, the UK also reported 5 cases of BA.2.12.1. CovidGenomics UKConsortium (COG-UK), which monitors COVID-19 transmission in the UK, said the variant was first identified in the UK on 23 March.
Editor-in-Charge: Li Yuequn
Proofreader: Shi Gong