Washington, Mar 29 (EFE).- The more contagious Omicron BA.2 Covid-19 subvariant is now the dominant strain in the United States, according to the Centers for Disease Control (CDC) on Tuesday.
BA.2, more transmissible than the original that caused a record number of cases and peaked in January, has surged in parts of Asia and Europe, and is gaining strength in North America where it now accounts for over half (55 percent) of new US cases.
The US northeast has the highest prevalence of this subvariant, especially in the states of New York and New Jersey, where it is already over 70 percent.
However, the CDC estimates that more than 95 percent of Americans already have antibodies, acquired either from Covid-19 vaccines or from the disease itself, and the country has returned to virtual normalcy in recent weeks.
A few hours before the CDC released its data on Tuesday, the Food and Drug Administration (FDA) authorized a second booster dose of the Pfizer/BioNTech and Moderna vaccines for those over the age of 50 years and some immunocompromised people.
The second booster can be given four months after the first, the agency said in a statement.
For the immunocompromised, the FDA authorized a second Pfizer booster for those over 12 years of age who have undergone solid organ transplantation, or who are living with conditions considered to have an equivalent level of immunocompromise, and the Moderna booster for those over 18 years of age with the same certain kinds of immunocompromise.
According to the US regulator, scientific evidence suggests that there is some waning of protection over time,” so a second booster “could help increase protection levels for these higher-risk individuals.”
About 65.5 percent of the US population is double vaccinated and of these, 44.8 percent have received one booster dose, according to the CDC.
The US is the country hardest hit by the pandemic in absolute numbers, with 80 million infections and 944,000 deaths, according to a count by Johns Hopkins University. EFE