In recent times, an area of concern amid the COVID-19 pandemic is the emergence of new variants. Similar to all other viruses, the SARS-CoV-2 virus mutates over time to help it survive and reproduce as per natural selection. These variants have different origins but share a mutation in a gene that encodes the spike protein, which the virus uses to latch on to and enter human cells. This change results in the virus binding to human cells more efficiently.
Jean-Paul Soucy, a Ph.D. student at the University of Toronto's Dalla Lana School of Public Health, said a particular strain of a virus is considered a variant when it has enough mutations to change a minor portion of its genetic code. As of right now, strains from several parts of the world are considered variants. Firstly, the Danish authorities have identified only 12 human cases of the Cluster 5 variant in September 2020, but fortunately, this variant did not spread further. However, the U.K. variant, known as SARS-CoV-2 VOC 202012/01 (Variant of Concern, the year 2020, month 12, variant 01), has spread globally. This new variant has 23 new nucleotide substitutions that lead to increased transmission rates.
Similarly, the 501.V2 variant from South Africa has propagated to other countries. There is no clear evidence of both these variants being associated with more severe disease or worse outcomes. What is concerning is the rate at which these COVID-19 variants disseminate.
In response to the emergence of new variants, intensified sampling is being conducted to understand how widely these new variants are circulating. Further investigations are required to understand the impact of specific mutations on viral properties and the effectiveness of diagnostics, therapeutics and vaccines. However, extensive research on vaccines' effectiveness on variants is not needed as they produce a broad immune response. Even if a variant were to diminish a vaccine's efficacy slightly, it would still offer some degree of protection. Additionally, mRNA vaccines can be easily modified to target new variants. Currently, Moderna's initial testing found that their vaccine is effective against these new variants to some extent, whereas Pzifer's was less effective.
These variants are concerning as they lead to increased transmission rates. Dr. Eric Topol, a U.S. physician, scientist and clinical trials expert who heads the Scripps Research Translational Institute in California, states that "If a strain is more infectious, substantially more, that means more deaths, more hospitalizations" While many of the public health guidelines recommended to stop the coronavirus spread are thought to be effective against the variants, experts say we should be doubling down on them and avoiding risky situations. Physical distancing, mask-wearing, hand hygiene and avoiding crowds are all effective. However, Dr. Tom Frieden, the former director of CDC, says people should also reduce their time spent indoors with those they don't live with, wear better quality masks such as N95s or surgical masks and have as few in-person interactions with others as possible.