The mutation and evolution of Omikeron is still ongoing.
The latest data from the US Centers for Disease Control and Prevention show that although the subtype BA.2 of the mutated new coronavirus Omiljung strain is still the main epidemic strain in the United States, the infection cases caused by another new subtype, BA.2.12.1, are rising rapidly.
According to the U.S. Centers for Disease Control and Prevention, in the week ended April 23, THE NUMBER OF INFECTIONS CAUSED BY BA.2.12.1 HAS ACCOUNTED FOR NEARLY 30% OF THE TOTAL NUMBER OF CONFIRMED CASES IN THE UNITED. In some regions of the northeast, BA.2.12.1 has surpassed BA.2 as the dominant epidemic strain.
U.S. Center for Disease Control and Prevention Roger Vronsky recently said that the spread of BA.2.12.1 may be 25% stronger than BA.2, and its impact on the effectiveness of the new crown vaccine is currently being studied.
Vronsky also said that experts believe that people who have been vaccinated against the new crown, especially those who have received booster injections, can still get better protection against severe diseases even in the face of BA.2.12.1.
Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota, said the mutation of the new coronavirus is much faster and more extensive than initially thought.
Multiple new variants spread in the United States
In addition to BA.2 and BA.2.12.1, the Washington Post recently reported that new subtypes of the Omiqueron strain are still emerging.
Among them, there are BA.4 and BA.5 subtypes of strains previously discovered by South African scientists.
According to the study of South African experts, people who were infected with the new coronavirus before TheOmilon may not have much immunity to BA.4 and BA.5; those who have been infected with the Semikron but have not been vaccinated do not have strong immune protection; and for those who have been vaccinated and infected with the Omilon virus, they are relatively adequate, at least effective in avoiding severe disease. Considering that BA.4 and BA.5 are not much different from the original Amiceton virus, this result is surprising.
Because the virus enhances infectivity and immunity escape, researchers believe that BA.4 and BA.5 have the potential to lead to a "new wave of infections."
U.S. health experts confirm that BA.4 and BA.5 have begun to spread in the United States. Although current cases of infection with BA.4 and BA.5 account for a small percentage of the number of sequenced cases in the United States, these two variants have been listed as "worthy of attention" variants. Whether they will cause a surge in the number of COVID-19 cases in the United States remains to be seen.
According to the Global Influenza Shared Database (GISAID), there are currently 12 cases of BA.4 variants and 5 BA.5 variants in the United States.
Expert: Viruses don't tire of us
Foreign media said that at present, it seems that the new crown virus strain will evolve more variants or sub-variants, and there is still a lot of "evolution space" for the virus strain, which is difficult for humans to control.
Fauci, director of the National Institute of Allergy and Infectious Diseases, said on April 29 local time that the new crown pandemic is not over, and the United States is unlikely to eliminate the new crown epidemic, but efforts should be made to control the virus. Fauci stressed: "It (COVID-19) is not over, we are still experiencing a global pandemic. ”
Dr. Deborah, former coordinator of the White House Covid-19 Response Task Force, said the government should be prepared for a possible surge in summer COVID-19 cases in southern states. She explained that the body's natural immunity generally weakens after 4-6 months, when it will cause a large number of cases to surge. She also stressed that public health officials need to show the public that natural immunity weakens over time and remind susceptible and low-resistance populations to take precautions.
However, Madison, an expert at drug companies working on covid-19, believes that BA.4 may increase the number of confirmed covid-19 cases in South Africa, but the same situation may not happen in the United States. "The patterns of human-to-human contact vary from country to country, and the nature of human immunity varies, so the situation in the United States and South Africa may not be the same," he explains. ”
Andy, a virologist at the Johns Hopkins School of Public Health, also believes that although both BA.4 and BA.5 have mutations, antibodies acquired after infection with BA.1 and BA.2 may still be useful for BA.4 and BA.5, so it is unlikely that there will be an increase in the number of "explosive" confirmed cases.
However, South African expert Turio disagreed. He believes that people who have previously been infected with the BA.1 variant are still very likely to be infected with BA.4 and BA.5. Turio said: "We may be tired of the virus, but the virus will not tire of us. ”
While experts have different views on the mutation of the virus, they generally agree that vaccination is still the best way to prevent infection and maintain immunity.
Shanghai News Broadcast is synthesized from Xinhua News Agency and Shangguan News
Editor: Yan Ping
Editor-in-Charge: Cheng Chen