The director of the Center for Disease Control and Prevention, Dr. Robert Redfield, holds up a CDC document that reads "COVID-19 Vaccination Program Interim Playbook for Jurisdiction Operations" as he speaks during a Senate Subcommittee hearing on Capitol Hill. Washington, USA, September 16, 2020.
Andrew Harnik | Reuters
A more contagious strain of the coronavirus, first found in the UK late last year, could become the dominant strain in the United States by March as the nation seeks to vaccinate people against the disease, according to a new study by the Centers for Disease Control fights contraception.
"The modeled trajectory of this variant in the USA shows Rapid growth in early 2021, which will become the predominant variant in March, "according to the CDC study published on Friday.
The researchers warned that increasing its spread could place a greater strain on the country's hospitals and require greater public health action to curb transmission of the virus until enough people are vaccinated. Increased surveillance of the mutating viruses, coupled with better compliance with public health measures such as masks, hand washing and physical distancing, could help slow the spread of the virus.
"These measures will be more effective if taken sooner rather than later to slow the initial spread of variant B.1.1.7. Efforts to prepare the health system for further spikes in certain cases are warranted," the researchers said.
So far, according to CDC data, which were last updated on Wednesday, the country has only found 76 Covid-19 cases with the highly infectious variant B.1.1.7. However, many of the identified cases involved people with no travel history, suggesting that the variant is spreading undetected in the community.
Global health experts have claimed that while the new strain in the UK and a similar strain in South Africa are more contagious, they don't seem to make people sick or make a person more likely to die.
However, more cases could ultimately lead to additional hospital stays if the nation is already home to record Covid-19 patients. The rapid transmission of the new variants could require more people to be vaccinated in order to achieve something called herd immunity, the researchers said.
Herd immunity is when enough of the population is immune to a disease, either through vaccination or natural infection, which makes it unlikely to spread and protect the rest of the community, the Mayo Clinic says.
The US has been sluggish in its vaccination efforts and missed its target of vaccinating 20 million people by the end of last year. The US has delivered more than 31.1 million doses to date, but only administered 12.3 million of them according to CDC data.
There is also concern that the new variants, particularly the strain found in South Africa, may be more resistant to monoclonal antibody treatments, which have been shown to reduce the chances of someone ending up in hospital if infected early enough.
The CDC study
The agency's investigation found that the current prevalence of the variant in the US is still unknown, but based on its analysis it accounts for less than 0.5% of cases. The USA has not yet discovered the variant found in South Africa or another strain identified in Japan in travelers from Brazil.
In their model, the researchers estimated that the variant was 50% more transmissible than the current strains. They also estimate that between 10% and 30% of people already have immunity to pre-existing infections and will be given 1 million doses of vaccine daily starting this month.
Although the prevalence of strain B.1.1.7 is estimated to be low due to its high transferability, it is likely to grow rapidly in early 2021, as the model showed. Even with vaccines, the variant will continue to spread, although the drugs showed the greatest effect in reducing the transmission of the strain in places where the disease was already regressing.
"Early efforts that can limit the spread of variant B.1.1.7, such as universal and increased adherence to public health containment strategies, will leave more time for ongoing vaccinations to achieve higher population immunity," said it in the study.