Dr. Rochelle Walensky, selected as director of the Centers for Disease Control and Prevention, speaks during an event at the Queen Theater in Wilmington, Del., Tuesday, December 8, 2020.
Susan Walsh | AP
The United States needs to swiftly deploy Covid-19 vaccines and step up its surveillance before highly contagious variants set in or the virus mutates again and makes the pandemic worse, said CDC Director Dr. Rochelle Walensky on Wednesday.
Three variants, first identified in the UK, South Africa and Brazil, have caused researchers some concern, according to a research suggestion shared with White House Chief Medical Officer Dr. Anthony Fauci. A CDC study published in January warned that variant B.1.1.7 found in the UK is expected to be the dominant strain in the US by March.
The B.1.1.7 variant has been shown to be highly transmissible, and “preliminary data suggest the possibility of increased disease severity with infection,” wrote Walensky, Fauci and Dr. Henry Walke, CDC’s Covid Incident Manager, in the position published Wednesday in the 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 suggests it could be up to 50% more virulent or deadly.
“Model data has shown how a more contagious variant like B.1.1.7 has the potential to exacerbate the US pandemic trajectory and reverse the current downward trend in new infections and further delay control of the pandemic,” Walensky said in the newspaper .
The rise of the variants
So far, the USA has identified at least 1,277 Covid 19 cases with variant B.1.1.7 from Great Britain, 19 of variant B.1.351 discovered in South Africa and three cases of variant P.1 identified in Brazil according to the latest data from the CDC.
Monitoring of the variants in a commercial laboratory in early February suggests that the prevalence of the B.1.1.7 variant is likely to be 1% nationwide, although the prevalence could exceed 2% in some states, according to the paper.
However, the more the virus circulates and infects other people, the more likely it is that it will mutate. This is one of the reasons global health experts have urged public health measures such as social distancing, frequent hand washing and wearing of masks to be doubled until vaccines can be used and the population can achieve what is known as herd immunity.
A virus that spreads faster would also mean more people would need to be vaccinated to build an umbrella of immunity, experts have said. In the US, the levels of virus spread in the community must be “aggressively reduced” and Americans should postpone travel and avoid crowds to ensure the variants do not spread further, the leading federal health officials wrote in their view.
“The more they mutate, the more likely we are to see dominant variants that really show up and could become a problem for us,” Walensky told JAMA. “The best we can do to prevent this from happening in general is to have fewer diseases circulating and fewer viruses circulating.”
Speed up vaccinations
The US needs to accelerate the pace of vaccination to “reduce transmission, and therefore the virus replication that creates opportunities for the variants in question,” especially where the virus is spreading fastest, the officials said.
Early data suggests that the B.1.351 variant, first found in South Africa, may be able to escape the natural immunity acquired by people recovering from Covid-19. “As a result, vaccines currently in use may be less effective in preventing infection.” Variant.”
The problem is not limited to the US. So far, countries that have been able to introduce vaccines for their populations have mostly been in higher-income countries that have supply agreements with the pharmaceutical companies.
“If viruses are still circulating in large quantities in other countries and other parts of the world … they will continue to pose a threat to us because those variants will in fact continue to threaten whether our vaccines will continue to work. So that is it.” a global problem, “said Walensky.
Monitoring is missing
The nation’s response should not only cover the variants found in the UK, South Africa and Brazil, but also be prepared to recognize mutations that can occur domestically, Walensky said.
The country’s infrastructure for carrying out “genome sequence monitoring” for the variants in the USA has not been sufficiently prepared to detect the circulating strains.
The CDC has partnered with public health and trade laboratories to rapidly improve genome sequencing in the country. In January, the US sequenced only 250 samples per week for the variants, which have 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’ll have to choose it,” said Walensky.