Variant BA.2 appears to overwhelm BA.1 with a faster spread. The two Omicron variants do not cause severe disease like the Delta variant, nor do they specifically cause severe disease in children.
“COVID-19 can be considered an endemic disease” – this was the statement of Dr. Truong Huu Khanh (Former Director of Infectious Neurology, Children’s Hospital No. 1, Ho Chi Minh City) before the COVID-19 pandemic. Mainly the Omicron variant.
Talking to PV VOV.VN, Dr Khanh said that the COVID-19 epidemic relieved the pressure when the Omicron variant emerged, and the Omicron sub-variant BA.2 did not even have the same effect as BA. first.
“Theoretically, if a new variant of the SARS-CoV-2 virus emerges, the new variant must spread more aggressively to overwhelm Omicron’s BA.1 and BA.2. If a new strain emerges, but is less contagious than the old one, This should not be a problem. BA.3 variants do appear, but biology and transmissibility are no exception, so there should be no problem. As the epidemic progresses to the main Omicron variant, when severe disease progresses, it may appear in In the unlikely event that COVID-19 is considered endemic,” Dr Khanh said.
The BA.2 sub-variant of the Omicron variant is called the “stealth variant”. This means that the PCR test was not detected due to a genetic defect in this subvariate, and the test may have been negative for the first 2-3 days.
Dr Khanh said a certain percentage of people were still infected with the Delta variant. Therefore, people can neither neglect nor pay too much attention to the epidemic prevention work: “At present, the Omircon variant is dominant in the world. The subvariants BA.1 and BA.2 have similar biological characteristics, but BA.2 seems to be faster.” The transmissibility of the two Omicron variants is predominant in BA.1, and the two Omicron variants do not cause as severe disease as the Delta variant, especially in children.
According to the statistics in early March 2022, the Omicron subspecies has a rapid infection trend in various provinces, especially Hanoi and Ho Chi Minh City, and gradually replaces the Delta strain.
In Hanoi, variants of Omicron were recorded in 20/30 regions, with BA.2 accounting for 87% of the total number of Omicron-contaminated samples detected. The “Omicron Stealth BA.2” variant accounted for 64% according to HCMC’s randomized screening assessment.
Globally, the BA.2 sub-variant of Omicron accounted for about 86% of recorded COVID-19 cases between February 16 and March 17, and is responsible for the current wave of infections in Europe. Although BA.2 is more contagious than the parental strain, it does not cause more severe disease, and currently available vaccines are effective against this variant.
Also according to recent research, people who have received the primary vaccine, booster vaccine, and COVID-19 will have the best protection against the BA.2 subvariable of Omicron.
People with “mixed” immunity to the vaccine and immunity to previous COVID-19 infection can reduce the risk of reinfection by 55%. In the Danish study, the BA.2 variant was found in most cases, and genetic sequencing showed that people who were already infected with BA.1 were rarely reinfected with the variant. Body BA.1. .Body BA.2. The scientists looked at data on more than 1.8 million cases over the 3-month period from November 2021 to February 2022 and found that only 47 cases were reinfected with the BA.2 variant after BA infection. . . . first. Most people are not vaccinated.
In evaluating the evolution of Omicron variant infection, domestic and foreign experts said that BA.2 is more contagious than BA.1, but the cases are heavier and the mortality rate is lower. This suggests that the body is immune to the occurrence of any submutation.