'Stealth' Omicron variant dominates in Ho Chi Minh City
Of the 67 Omicron-infected patient samples in Ho Chi Minh City whose virus genes were decoded, 24 samples were the BA.1 strain and 43 samples were the BA.2 strain, also known as the stealth strain.
Director of the City Health Department Tang Chi Thuong announced the above information at the Steering Committee meeting.COVID-19 preventionand economic recovery, morning of March 9.
"Ho Chi Minh City currently has both Omicron and BA.2 strains dominating, which explains why the epidemic is spreading so quickly. We should not worry too much because the new variant is already present in the city," said Mr. Thuong.
According to Mr. Thuong, the World Health Organization (WHO) confirmed that the vaccine is still capable of protecting the body when infected with the BA.2 variant, but is not strong enough to prevent the body from being infected. Therefore, the vaccination campaign still needs to be strengthened.
This is the first time the Omicron BA.2 sub-strain has been recorded in Vietnam. BA.2 is a sub-strain of Omicron (the original strain is BA.1). It is called a stealth variant because it does not contain the characteristic mutation of Omicron, is believed to be able to evade rapid testing and can be detected by PCR testing.
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| Director of Ho Chi Minh City Department of Health Tang Chi Thuong reported at the meeting on the morning of March 9. Photo: Huu Cong |
According to studies worldwide, BA.2 does not cause more severe symptoms than the original Omicron strain BA.1, but it spreads faster. BA.2 differs from BA.1 in its genetic sequence, with changes in amino acids in the spike protein and other proteins. Research shows that BA.2 has a growth advantage over BA.1. Scientists have recorded some cases of reinfection with BA.2 after infection with BA.1, which means being infected with Omicron twice. However, the natural immunity from BA.1 is strong enough to fight BA.2.
As of this morning, Ho Chi Minh City has recorded more than 93,000 F0 cases, of which the majority are being treated at home, 4,815 cases are being treated at the hospital on the 2nd floor and 552 cases are being treated at the hospital on the 3rd floor; 63 cases are on invasive ventilators. Severe cases are concentrated in the group over 65 years old, not vaccinated, and have many underlying diseases.
From March 1-7, Ho Chi Minh City recorded nearly 37,500 suspected cases in schools, nearly double that of the previous week. 454 schools had F0 cases, the number of suspected cases increased steadily in all grades, with the highest in primary school.
The reason for the increase in F0 in schools, according to the Department of Health, is that schools proactively screen students, teachers, and workers with symptoms; periodically test F1, families quickly test students themselves...
At 3 Children's Hospitals, there are currently 20 cases requiring respiratory support (12 cases in the province); 5 cases on invasive mechanical ventilation (4 cases in the province)...
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| Microscopic image of the Omicron variant. Photo: Kyodo |
At the meeting, Chairman of the Ho Chi Minh City People's Committee Phan Van Mai said that experts predicted that the city would have another wave of the epidemic. Therefore, the Department of Health needs to analyze and evaluate to correctly assess the epidemic situation and come up with appropriate solutions.
After 3 weeks of in-person learning, the city recorded many new infections. Mr. Mai asked relevant units to update and adjust solutions to ensure safety for students.