Most recently, strains BA.4 and BA.5 have become the dominant variants causing the disease COVID-19 in the US. Experts warn that although this variant is assessed as having a low level of danger, it cannot be subjective because with its rapid spread rate, this variant can create a new wave of epidemics.
According to the US Centers for Disease Control and Prevention (CDC), as of July 2, it is estimated that BA.4 and BA.5 accounted for more than 70% of the variants of the SARS-CoV-2 virus circulating in the US. Currently, the US has recorded an average of nearly 110,000 new cases per day, about 10,000 cases higher than the average a week ago.
A report published in the scientific journal Nature found that even people who have “hybrid immunity” from vaccination and have been infected with the BA.1 strain are still less likely to be able to prevent reinfection from the BA.4 or BA strains. .5. Experts believe this is largely due to changes in the mutated proteins of the virus.
Two pharmaceutical companies Pfizer and Moderna, which manufacture mRNA-based COVID-19 vaccines, have developed and tested a specific vaccine against the BA.1 subvariant. According to these two pharmaceutical companies, it takes about 3 months to be able to produce a new version of the COVID-19 vaccine, specifically preventing subvariants BA.4 and BA.5.
A positive sign is that according to experts, so far the BA.5 variant has not caused more severe disease. Reported symptoms have not changed much, and the death rate in the US remains lower than during the Omicron outbreak in winter 2021.
However, experts recommend that people over the age of 50 should not delay the booster shot because the risk of reinfection is very high at this time. Meanwhile, the European Agency for Disease Control and Prevention warned, BA.4 and BA.5 will become mainstream variants in this region.
Source: VTV