It is understood that the newly emerged mutant strains BA.4 and BA.5 have stronger transmission ability than the Omicron mutant strain BA.2, and have now become mainstream viruses in Europe and the United States.
According to the US Centers for Disease Control and Prevention (CDC), as of June 18,BA.4/5 accounted for 34.9% of new cases in the United States in the week of June 18, soared 61.57% from the previous week, and on June 11, the merger of BA.4 and BA.5 accounted for 21.6% in the United States, of which BA.4 accounted for 8.3% and BA.5 accounted for 13.3%.
According to the European Centre for Disease Prevention and Control (ECDC), BA.4/5 is the fastest-spreading variant reported so far, and both variants are expected to be circulating in the US, UK and other parts of Europe in the coming weeks the main strain.
Compared with the current global leading strain BA.2, the new key mutations in the spike protein of BA.4/5 include L452R and F486V. The most important change brought about by these mutations is that BA.4/ can easily escape the human body some immune systems,Even people who have been vaccinated against the new crown virus and infected with the new crown virus cannot avoid the possibility of being infected and re-infected.
However, although the mutant virus has a stronger transmission ability, the treatment method is the same as the previous virus strain, and the harm to the human body is not more serious, so there is no need to worry too much.