By Gary Evans, Medical Writer

With two recent case reports from Minnesota and South Carolina, all three SARS-CoV-2 variants of global concern are now in the United States.

They threaten to erode vaccine efficacy, undermine treatment, and increase both hospitalizations and deaths. Current vaccines are expected to hold against these highly transmissible variant strains, although efficacy may be diminished. With vaccine supply limited, masking, social distancing, and hand hygiene will be critical over the next few months.

For now, the remarkable 94% to 95% efficacy of the two available COVID-19 vaccines creates a buffer, meaning some degradation of their effectiveness would still keep people out of the hospital and the morgue — a truism often applied to flu shots.

On Jan. 28, 2021, the Centers for Disease Control and Prevention (CDC) announced that the first U.S. documented case of the South African B.1.351 variant of SARS-CoV-2 had been detected in South Carolina. The CDC did not name the city where the case was found. This comes only three days after the first U.S. case of the Brazil P.1 variant was detected in the Twin Cities metro area in Minnesota. The United Kingdom (UK) B.1.1.7 variant has been in the United States for some time, and is projected to become the predominant strain in America by March of this year. Researchers in England are warning that in addition to be being highly transmissible, there is “a realistic possibility” the variant may cause infections with higher rates of mortality.

Based on limited genetic sequencing, as of Jan. 27, 2021, there were 315 cases of COVID-19 in 28 states caused by the UK B.1.1.7 variant, according to the CDC.

Fortunately, both approved vaccines in the United States are effective against UK B.1.1.7. However, Moderna is concerned that the South African variant could diminish the effect of its vaccine and is preparing a one-time booster shot genetically coded to the B.1.351 variant should it be necessary.

Over time, as SARS-CoV-2 persists and globally circulates, treatments and vaccines will likely have to be augmented to meet the threat of variant mutations. A key message is that the variants make vaccination all the more important, as mutations will continue to arise if SARS-CoV-2 runs unchecked through large populations, said Anthony Fauci, MD, director of the National Institute of Allergy and Infectious Disease at a press conference.

“It is all the more reason why we should be vaccinating as many people as we possibly can,” he said. “Viruses don’t mutate unless they replicate. If you can suppress that by a very good vaccine campaign, then we can avoid this deleterious effect of mutations.”

For more on this story, see the March 2021 issue of Hospital Employee Health.