With the Sri Lankan government successfully completing the first phase of the Covid-19 vaccination rollout, the number of new cases reported daily appear to be on the decline. While governments around the world scramble to do the same, a new challenge emerges: New variants of the SARS-CoV-2 virus.
While some research suggests that the new variants are potentially more infectious, three major COVID-19 variants have emerged across the globe. And scientists say that these variants may be cause for concern. But how are they different from the original strain and why should we be worried?
Why do viruses mutate?
In order to infect a person, a virus takes over a host cell and uses it to replicate itself. But this replication process can’t guarantee an exact replication.
A virus with one or more mutations is referred to as a variant. Most of the time, variants do not affect a virus’s physical structure, and in those instances, they eventually disappear. However, there are certain cases when a mutation impacts part of a virus’s genetic makeup that does change its behaviour. From what we know about the genetic evolution of SARS-CoV-2, it appears that the virus is mutating relatively slowly as compared to other RNA viruses.
According to the U.S. Centers for Disease Control (CDC) a change in behavior can alter:
- Rate of transmission
- Ability to potentially infect someone with natural or vaccine-induced immunity
Preliminary research has detected some of these changes in the three major COVID-19 variants—B.1.1.7, B.1.351, and P.1. So far strains from South African (the B.1.351 strain) and UK (the B.1.1.7 strain) have been identified through patients who tested positive for COVID-19 in Sri Lanka.
What causes a virus to change to a new variant?
When a virus is widely circulating in a population and causing many infections, the likelihood of the virus mutating increases. The more opportunities a virus has to spread, the more it replicates – and the more opportunities it has to undergo changes. Most viral mutations have little to no impact on the virus’s ability to cause infections and disease. But depending on where the changes are located in the virus’s genetic material, they may affect a virus’s properties, such as transmission (for example, it may spread more or less easily) or severity (for example, it may cause more or less severe disease). The 3 Major COVID-19 Variants
The three major variants emerged at different times, and in different parts of the world. Here’s an overview of each variant, when they were discovered, and how far they’ve spread so far. B.1.1.7
The B.1.1.7 variant was detected in the UK in the fall of 2020. By December 2020, it had spread across the globe, with cases emerging across Europe, North America, and Asia. Currently, the variant has been reported in roughly 94 countries.
Early research suggests it’s 50% more transmissible than other variants, and potentially 35% more deadly than the standard virus. Luckily, studies suggest that some of the existing vaccines work well against it. B.1.351
In October 2020, the second major variant was discovered —B.1.351. It was first identified in South Africa, but by end of the year, it had spread to the UK, Switzerland, Australia, and Japan.
There are approximately 48 countries with reported cases, and research suggests several of the existing COVID-19 vaccines may not be as effective against this
The P.1 variant was the last to arrive on the scene. It was first discovered in January 2021, when Japan reported four cases of the variant, which was found in travelers who had arrived from Brazil.
What impact do the new variants of the COVID-19 virus have on vaccines?
The COVID-19 vaccines that are currently in development or have been approved are expected to provide at least some protection against new virus variants because these vaccines elicit a broad immune response involving a range of antibodies and cells. Therefore, changes or mutations in the virus should not make vaccines completely ineffective. In the event that any of these vaccines prove to be less effective against one or more variants, it will be possible to change the composition of the vaccines to protect against these variants.
Data continues to be collected and analysed on new variants of the COVID-19 virus. WHO is working with researchers, health officials and scientists to understand how these variants affect the virus’s behaviour, including their impact on the effectiveness of vaccines, if any. This is an area where the evidence remains preliminary and is
Source: WHO, CDC, Science Daily, NY Times, Columbia University Irving Medical Center, US Centre for Infectious Disease Research and Policy, Imperial College London, Straits Times.