The United States must rapidly deploy Covid-19 vaccines and step up surveillance before highly contagious variants catch or the virus moves again and worsens the pandemic, CDC Director Dr. Rochelle Walensky said Wednesday.
Three variants first identified in the UK, South Africa and Brazil have given researchers some concern, according to a research opinion he co-wrote with Dr Anthony Fauci, the White House chief adviser. A CDC study published in January warned that the variant found in the UK, known as B.1.1.7, would likely become the dominant strain circulating in the US by March.
Variant B.1.1.7 proved to be highly transmissible and “preliminary data suggest the possibility of increasing the severity of the infectious disease,” wrote Walensky, Fauci and Dr. Henry Walke, CDC’s Covid incident manager, in a statement published Wednesday Journal of the American Medical Association or JAMA.
Walensky told JAMA in a separate interview on Wednesday that the variant is believed to be about 50% more transmissible than previous strains, and early data suggest it could be up to 50% more virulent or deadly.
“Modeling data illustrated how a more contagious variant, such as B.1.1.7, has the potential to exacerbate the trajectory of the US pandemic and reverse the current downward trend in new infections and delay pandemic control,” Walensky said. he said in the paper.
To date, the US has identified at least 1,277 Covid-19 cases with variant B.1.1.7 From Great Britain, 19 of variant B.1.351, which was discovered in South Africa and three cases of variant P.1 found in Brazil, according to recent CDC data.
Surveillance of variants at a commercial laboratory in early February suggests that at national level the prevalence of variant B.1.1.7 is probably close to 1%, although the prevalence in some states could exceed 2%, according to the paper.
However, the more the virus circulates and infects people, the more likely they are to move. This is part of the reason why global health experts have lobbied for people to double public health measures, such as social distancing, frequent hand washing and wearing masks, until vaccines can be implemented and people can reaches the so-called immunity of the herd.
A faster-spreading virus would also mean more people should be vaccinated to build an immune umbrella, experts said. In the US, the level of viral spread in the community must be “aggressively low,” and Americans should delay travel and avoid congestion to ensure that variants do not continue to spread, they wrote. federal health officials.
“The more it moves, the more likely we are to see dominant variants that could really emerge and become a problem for us,” Walensky told JAMA. So the best thing we can do to prevent them in general is to have fewer diseases circulating, fewer viruses circulating.
Surveillance is missing
The nation’s response should not only address variants found in the UK, South Africa and Brazil, but it should also be prepared to detect mutations that may occur internally, Walensky said.
The country’s infrastructure to perform “genome sequence monitoring” for US variants has so far been poorly prepared to detect circulating strains.
The CDC has worked with public and commercial health laboratories to rapidly expand the nation’s genomic sequencing. In January, the United States sequenced only 250 samples per week for variants, which has since grown “by the thousands,” Walensky said. However, she added that “we are not where we need to be”.
“It’s going to be a dial, not a switch, and we need to call it,” Walensky said.
This is a developing story. Please come back later for updates.