Hanoi (VNA)♛ – The SARS-CoV-2 Omicron sub-lineages BA.4 and BA.5 have entered Vietnam and may overwhelm the old sub-lineage BA.2, the dominant variant of concern in the country, according to Prof. Dr. Phan Trong Lan, Director of the Health Ministry’s Department of Preventive Medicine.

Prof. Lan said that gene sequencing results showed that the sub-variant BA.5 of Omicron has been found in Vietnam. “This variant may overwhelm the old sub-variants (BA.1 and BA.2)," he said. The intrusion is inevitable because the sub-variant has been seen in countries in Europe and the US and travel activities among countries are ongoing, he said, adding that the Ministry of Health will continue to monitor pandemic developments. The number of COVID-19 cases has been falling with a very low ratio of infections and deaths. Patients mostly suffered Omicron’s sub-variant BA.2 with mild symptoms. The majority of the cases were recorded in the northern region with about 107,000 in the last two months. Prof. Lan attributed the results to a high vaccination ratio and effective activities to protect high-risks groups. He said initial research showed the Omicron sub-lineages BA.4 and BA.5 spread faster than BA.1 and BA.2. There has been no specific evidence on the new sub-variants’ virulence, but some studies indicated that there is an aggravation in the African region. The World Health Organisation has warned that as the new variants of SARS-CoV-2 are making the pandemic complicated again, countries need to maintain measures such as vaccination and monitoring. The Health Ministry called on people, especially those at a high risk of infection, to be fully vaccinated against COVID-19. As of June 26, the national caseload reached 10,743,448. On the day, 345,608 doses of vaccines were administered, raising the total number of doses of COVID-19 vaccines injected to 229,551,802. Lan said that Omicron may not be the last variant of SARS-CoV-2. He said that the SARS-CoV-2 is constantly changing, making it difficult to determine the dangerous nature of the variants and the degree of aggravation and fatality risks. Currently Omicron is the most ubiquitous variant in the world but it is not the final one, he stressed. According to the Ministry of Health, there may be new variants of the SARS-CoV-2 that can reduce the effectiveness of COVID-19 vaccines or immunity, causing an increase in the number of cases with severe symptoms or a rise in death toll, especially among vulnerable groups. In Vietnam, there is still a downward trend in the number of new cases and the mortality/infection rate is very low. The main circulating variant is the BA.2 variant of Omicron with mild clinical symptoms. According to Professor Phan Trong Lan, in the past two months, northern provinces recorded more than 106,000 cases of COVID-19, 10 times higher than the total recorded from those in the south, while localities in the central region reported more than 8,000 cases in total. Meanwhile, in the world, in the week from May 23 to 29, compared with the previous week, the total number of new cases in the Americas increased by 9%, while that in the Middle East increased by 1%. The total number of deaths also rose by 18% in the Western Pacific region, including Vietnam, 15% in Africa, and 13% in the Americas. According to the Ministry of Health, the above figures may not fully reflect the actual situation because many countries have significantly eased their testing requirements and lessened their attention compared to the previous period. In addition, the number of COVID-19 cases in children is increasing in some countries, including the US, said Lan./.