CDC: Act Now Against Highly Infectious COVID B.1.1.7

The Centers for Disease Control and Prevention (CDC) wants to get across to the public, elected officials and health care professionals that a quick response must be taken against the highly infectious strain of coronavirus disease 2019 (COVID-19) that first emerged in the United Kingdom. If that response doesn’t come, then B.1.1.7 will become the dominant strain of COVID-19 in the United States by March. There are 76 known cases of B.1.1.7 in the US as of this writing. The COVID-19 vaccines should be effective against B.1.1.7, but that’s not the point. More infections mean more hospitalizations and higher mortality rates, all of which puts more strain on an already strained-to-the-hilt health care system.

“The experience in the United Kingdom and the B.1.1.7 models presented in this report illustrate the impact a more contagious variant can have on the number of cases in a population,” says a study published in the CDC’s Morbidity and Mortality Weekly Report. “The increased transmissibility of this variant requires an even more rigorous combined implementation of vaccination and mitigation measures (e.g., distancing, masking, and hand hygiene) to control the spread of SARS-CoV-2. These measures will be more effective if they are instituted sooner rather than later to slow the initial spread of the B.1.1.7 variant.”

President-elect Joe Biden wants to distribute 100 million doses of COVID-19 vaccines in his first 100 days. They’ll be needed, says the study. “Increased transmissibility also means that higher than anticipated vaccination coverage must be attained to achieve the same level of disease control to protect the public compared with less transmissible variants,” the study states.

The CDC leads a coordinated effort that includes states, academia, industry and local health officials to enhance genomic surveillance of COVID-19 across the US. “Multiple lines of evidence indicate that B.1.1.7 is more efficiently transmitted compared with other SARS-CoV-2 variants circulating in the United Kingdom,” the study states. “UK regions with a higher proportion of B.1.1.7 sequences had faster epidemic growth than did other areas, diagnoses with SGTF[S-gene target failure] increased faster than did non-SGTF diagnoses in the same areas, and a higher proportion of contacts were infected by index patients with B.1.1.7 infections than by index patients infected with other variants.”

CDC investigators examine multiple models of how B.1.1.7 might spread. One of the models assumes that 1 million COVID-19 vaccines are distributed a day, beginning January 1, 2021. That model also says that 95% herd immunity was achieved 14 days after people were given the second dose of the vaccine. Obviously, this hasn’t happened (whether we can ever achieve herd immunity against COVID-19 is a matter of debate), but the investigators wanted to see how much a threat B.1.1.7 would present if near universal immunity against infection is assumed.

“In this model, B.1.1.7 prevalence is initially low, yet because it is more transmissible than are current variants, it exhibits rapid growth in early 2021, becoming the predominant variant in March,” the study state. “Whether transmission of current variants is increasing (initial Rt = 1.1) or slowly decreasing (initial Rt = 0.9) in January, B.1.1.7 drives a substantial change in the transmission trajectory and a new phase of exponential growth. With vaccination that protects against infection, the early epidemic trajectories do not change and B.1.1.7 spread still occurs.

However, in this model, after B.1.1.7’s transmission is substantially reduced after it becomes the dominant strain.

“The effect of vaccination on reducing transmission in the near term was greatest in the scenario in which transmission was already decreasing (initial Rt = 0.9),” the study states. “Early efforts that can limit the spread of the B.1.1.7 variant, such as universal and increased compliance with public health mitigation strategies, will allow more time for ongoing vaccination to achieve higher population-level immunity.”

The CDC’s findings come as COVID-19 rages out of control. Hospitals are packed. Infection preventionists and other health care professionals are working around the clock. They’re exhausted. Rochelle Walensky, MD, who will head the CDC in the Biden administration, warns that the death toll in the United States could very well reach 500,000 by mid-February. Yesterday, 1723 people died from COVID-19 in the US, while the country saw 174,513 newly confirmed cases of the disease, according to Johns Hopkins University.