With all the recent coverage of emerging variants of the SARS-CoV-2 virus, pharmacists are likely to get questions about what they mean and how they can best protect themselves. While the situation—and the virus—are rapidly evolving, here’s what is known right now.
Soumya Swaminathan, MD, chief scientist of the World Health Organization (WHO), recently noted that “[f]rom the beginning of the year, we’ve been tracking this virus and we know that it’s gone through a lot of changes and there’ve been variants before.” In itself, development of a mutation is no big deal, but two of the new variants, which feature an unusually large number of mutations, raised some flags starting in December. “And the reason there’s concern is that both of these variants were associated with an increase in the number of cases in both of these countries” where they originated, the UK and South Africa.
Research indicates that both the UK variant, known as B.1.1.1.7, and the South African variant, 501Y.V2, are about 50% more transmissible than the SARS-CoV-2 variant that has dominated across the world since March. These two variants developed independently but share several key mutations.
Most notably, these two variants and most of the others that raise concerns have significant alterations in the spike proteins that give the coronavirus its crown-like appearance as they protrude at regular intervals around the outside of the virus. The same protein is the calling card of the virus; it’s the primary antigen that the immune system protects against during and recognizes after an infection. It’s also the main target for most vaccines.
Initially, the UK variant was not thought to cause more serious disease, just more disease overall. On January 22, however, UK Prime Minister Boris Johnson announced that “[i]n addition to spreading more quickly, it also now appears that there is some evidence that the new variant . . . may be associated with a higher degree of mortality.” Of 1,000 60-year-olds infected with the old variant, 10 might be expected to die. With the new variant, that number rises to 13 or 14.
The UK variant has spread to more than 50 other countries and has been identified in at least 20 states so far. It’s almost certainly more widespread, as the U.S. sequences relatively few samples. Cases have been found in California, Colorado, Connecticut, Florida, Georgia, Illinois, Indiana, Louisiana, Maryland, Massachusetts, Michigan, Minnesota, New Mexico, New York, New Jersey, Oregon, Pennsylvania, Texas, Utah, Wisconsin, and Wyoming. The CDC recently warned that the UK variant will be the dominant strain in the U.S. by March and could drive a spring surge in cases.
The South African variant has spread to at least 14 countries. Francis deSouza, CEO of Illumina, the largest maker of genome sequencing equipment, believes the “chances are high” the strain is already in the U.S. but has not yet been detected. While it does not appear to be more deadly, one of its mutations may affect neutralization of the virus by some therapeutic monoclonal and polyclonal antibodies and could reduce response to current vaccines. The South African variant’s spike protein has rotated about 20 degrees, allowing it to bind more tightly to cells and allowing it to transmit and infect more efficiently.
A third variant, 20J/501Y.V3, arose in Brazil. Again, the mutations in the spike protein receptor pose the greatest risk. Current data suggest that the Brazilian variant is significantly more transmissible. More troubling, in the region where it originated, an estimated 75% of the population had been infected with SARS-CoV-2 as of October, but by mid-December, the area was hit again with a substantial surge in cases. That indicates that the combination of mutations in this variant increases the risk of reinfection and may reduce the effectiveness of vaccines.
Some troubling mutations have recently emerged in the U.S. as well. In Los Angeles, the CAL.20C strain, first identified in one case in July and not seen again until October, accounted for more than one-third of all cases in December. The spread of the variant coincided with the sharp surge of cases in the region. It has already been found in New York, Washington, DC; and in the Oceania region. The strain includes five recurring mutations, including one called L452R, which it shares with another strain that has spread rapidly in Northern California and in Europe.
In mid-January, researchers raised concerns about two new strains found in Ohio, as well, indicating that more of these potentially problematic strains likely will arise.
Whatever strain is circulating, three steps will control its spread: frequent hand washing, maintaining social distance, and wearing a mask. In light of the greater infectivity of the U.K. strain, the CDC recently urged people to upgrade to N95 masks or three-layer cotton masks for more protection.
Vaccination will also help. According to Anthony Fauci, MD, director of the National Institute of Allergies and Infectious Diseases, “right now, from the reports we have . . . it appears that the vaccines will still be effective against them.”
The content contained in this article is for informational purposes only. The content is not intended to be a substitute for professional advice. Reliance on any information provided in this article is solely at your own risk.
