Two new omicron subvariants known as BA.4 and BA.5 are gaining traction in the U.S., but how transmissible are they and what do we know about them?
According to the latest estimates from the Centers for Disease Control and Prevention, an omicron subvariant that has been the dominant strain of COVID-19 in the U.S. for more than a month is beginning to lose steam, and yet another variant of omicron is quickly gaining momentum.
Those estimates indicate that the BA.2.12.1 lineage of omicron continues to be the dominant strain of COVID-19 in the United States, and is responsible for an estimated 56% of cases.
That number continues to decline however as another strain, the BA.5 subvariant, continues to gain momentum, making up an estimated 23.5% of cases in the last week.
Those increases paint a troubling picture, as recent studies have suggested that previous coronavirus infections and COVID-19 vaccinations are less effective at preventing infection against the BA.4 and BA.5 omicron subvariants.
According to the New England Journal of Medicine, studies have shown that "the levels of neutralizing antibodies" that previous infection or vaccinations create in the body are less effective against the BA.4 and BA.5 subvariants, but still provide “substantial protection” against severe illness.
The research could indicate that BA.4 and BA.5 could cause increased infections among all populations, including those who have been vaccinated and boosted, but also indicates that those vaccinations will still help to guard against severe illness.
According to officials in Europe, the BA.4 and BA.5 subvariants will likely become the dominant strains of the virus in coming weeks, and those sublineages are already the dominant strains in South Africa, researchers told CNN.
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