COVID-19 vaccines are all the buzz right now as people scramble to get their lives back to a semblance of normalcy. Millions have been vaccinated, but new, mutated strains of coronavirus are causing concern around the world. COVID-19 cases have fallen nationwide, but health officials warn that these variants could trigger a new surge of infections.
A new variant of the coronavirus that causes COVID-19 was first reported in December 2020. Since then other variants have been identified. Are the new variants more contagious? Will the current vaccines cover them?
Variants occur when there is a change (mutation) to the virus’s genes. As a virus mutates, mistakes and changes are made in the copying of its genetic sequence. This is a classic case of evolution. If the changes are beneficial to the virus, they are more likely to persist as replication continues. As SARS-CoV-2 spreads, and replicates, the likelihood of these mutations increases. According to Dirk Dittmer, a professor in the department of microbiology and immunology within the UNC School of Medicine, “The number of infected people is tremendous, so there’s much more virus replication than ever before. Every person that’s infected is a little test tube that allows the virus to change.”
Since the original virus was first identified in December 2019, thousands of variants have been documented. Scientists are keeping a close eye on three of them they call “variants of concern.” Dr. Francis Collins, director of the National Institutes of Health, is a geneticist who 20 years ago oversaw the decoding of the human genome. He says he is “surprised by how much this virus is evolving.” He also states, “It turns out that some of these mutations actually change the behavior of this virus in a way that makes it more infectious or more serious. The evidence is that, for both the B117 — primarily seen in the UK but increasingly in the US — and the South African B1351, they are more transmissible. They’re just really successful.” Public health experts are also studying the Brazilian city of Manaus. COVID swept though the population last spring, leaving approximately 70% infected. Although some researchers believed the city had reached herd immunity, epidemiologists suspect thousands were reinfected with the Brazilian variant starting this past December. A recent study suggests the variant is more infectious than earlier strains and may be better at evading antibodies.
In recent weeks Houston became the first large American city to report the presence of all five variants that are concerning to medical experts: a California strain called B1427/B1429; a New York variant classified as B1526; the Brazilian P.1 strain; a strain called B1351 believed to have originated in South Africa; and the UK mutation B117, which the Centers for Disease Control and Prevention predicts will become the dominant strain in the United States by the end of March. B117 is estimated to be up to 70% more transmissible; it has become the leading cause of infection in the United Kingdom and has already been reported in 64 other countries. Each of these variants comes with its own new and concerning features. For example, the Brazilian P.1 strain has been found to make reinfection easier, while new studies show that B117 extends the infectious period beyond that of the original strain.
It is not the goal of a virus to kill people; its goal is to stay alive, and the only way it does that is by infecting people. Current vaccines cut down on the severity of disease, but they do not prevent people from getting or transmitting it. In addition, the clinical trials for the vaccines from Moderna and Pfizer occurred before variants were a factor.
Should we be concerned about these coronavirus variants? When the evidence is strong enough that a viral genetic change is causing a change in the behavior of the virus, we can further assess how the virus works. As with any virus, changes are something to be watched, to ensure that testing, treatment, and vaccines are still effective. Scientists will continue to examine new versions of coronavirus’s genetic sequencing as it evolves.
Meanwhile we need to continue to wear masks, wash our hands frequently especially when in public places, practice social distancing, and take good care of our immune systems. Vaccines can be helpful in controlling the pandemic, but they may not be able to prevent vaccinated people from developing less severe or asymptomatic infections and transmitting the virus to others, thus allowing future mutations to emerge. These won’t be the last variants we’ll see, and COVID-19 will continue to surprise us. We need to support and nurture our immune systems daily to protect ourselves from whatever may be lurking around the corner.
