The U.S. Centers for Disease Control and Prevention (CDC) announced on the 5th that the BA.
According to the US media The Hill, the CDC announced on the 2nd that as of the 2nd, BA.5 mutation accounted for 53.6% of new confirmed cases in the United States, and BA.4 accounted for 16.5%.
When the two sub-variations are combined, they account for 70% of the total.
BA.4 and BA.5 are sub-mutations derived from Omicron and have the characteristic of avoiding natural infection or immunity caused by existing vaccines.
These mutations accounted for only 1% in the United States even at the beginning of May, but on the 19th and 25th of last month they accounted for 15.7% and 36.6%, respectively, exceeding half of the total.
The number of daily COVID-19 cases in the United States is increasing.
The number of daily new confirmed cases, which recorded a maximum of 800,000 in January, when the omicron mutation epidemic peaked, gradually subsided and fell to the level of 30,000 in March, then increased again from the end of April, increasing to an average of 100,000 a day from May. .
The two mutations are now rapidly spreading not only in the U.S. but also around the world, leading the COVID-19 resurgence.
On the 29th of last month, Tedros Adhanom Ghebreyesus, director-general of the World Health Organization (WHO), announced that the number of confirmed COVID-19 cases, led by BA.4 and BA.5, increased in 110 countries.
Infectious disease expert Celine Gunder said, “BA.4 and BA.5 are much more mutated than the existing omicron mutations, and our immune system recognizes these submutations regardless of whether we have previously been vaccinated or infected with COVID-19. I’m having a hard time with it,” he said.
For this reason, the US health authorities have requested vaccine manufacturers to develop vaccines that block BA.4 and BA.5 mutations, not the Omicron prototype virus.
However, as the prospect that this improved vaccine may not be distributed in a timely manner in the United States has emerged, concerns have grown that the pandemic could once again strike the world this fall and winter.
Gunder said that the improved vaccine would not be available until October at the earliest and advised to get a booster shot (boost) in advance if possible.
Although the new mutation of Omicron has immune-avoidance properties, the general opinion of experts is that vaccination with the COVID-19 vaccine reduces the likelihood of severe illness or hospitalization.