New COVID-19 variant causes alarm
One full year into the COVID-19 pandemic, scientists know much more about the novel coronavirus and how it spreads than they did in December of 2019. They also have a better idea how it mutates. While mutation is expected to occur in all viruses, one particular variant first detected in the United Kingdom, appears to spread more quickly and has caused concerns that the pandemic may get worse in the coming months.
The concerning strain of the SARS-CoV-2 virus is known scientifically as B.1.1.7, but is widely referred to as the U.K. variant, because it was first identified in the United Kingdom and appears to be most widespread there. There is no evidence to suggest that the variant is more lethal or more resistant to vaccines, but many experts agree that it is more efficient at spreading from person to person. Viral loads of people infected with the variant – that is, the quantity of viral particles found in their systems – have been reported as significantly higher than the average. This means that people with the new variant may be more likely to pass the virus on to those around them, since they’re dispelling a larger number of viral particles every time they breathe.
The variant was first detected in September. At the time, it didn’t cause much alarm – like all viruses, the SAR-CoV-2 virus naturally mutates in small ways over time because of the core structure of viruses. The SARS-CoV-2 virus is made up of a single strand of RNA, a molecule that encodes genetic information, similar to our DNA. When the virus replicates, it sometimes produces random changes in that core sequence. The majority of these changes have no effect on the virus at all, and many of them are actually detrimental to the virus’s spread, causing many variants to quickly die out and be replaced by other, more stable strains.
A September report in the journal Nature found that SARS-CoV-2 developed new mutations at half the rate of the influenza virus, and one fourth the rate of HIV, suggesting mutation may be less of a concern with COVID-19 than with other diseases like the flu. The more the virus spreads, however, the more individual virus particles are replicating on any given day and the more total mutations can occur, increasing the chance for a mutation that gives one variant of the virus a competitive advantage.
When this happens – if a mutation develops, for example, that lets one variant spread faster than other ones – that variant will eventually outcompete and replace other variants, causing the virus to evolve. Many scientists say this is what appears to be occurring with the U.K. variant. By November, about two months after it was first identified, the new variant accounted for one quarter of all the cases in the country. By midDecember, it accounted for almost two thirds of the cases in the U.K.
The rise of the new variant also coincides with an increase in total case numbers in the country, suggesting that the increased communicability is causing the virus to spread faster. This may be because of the increased viral load that has been reported in some preliminary studies. A number of other factors could be contributing to the increase in cases as well. Cold weather may be driving people into more cramped indoor spaces, for example, or people may be traveling more because of the holidays.
However, the BBC reports that government advisors have “high” confidence that the new variant is more transmissible than previous ones and is a factor in the country’s recent surge.
In the United States, as of this weekend, the variant has been detected in Florida, California and Colorado in people with no travel history, suggesting that the variant is already spreading among communities in those states. It has also been detected in 33 different countries.
While the new variant has not yet been found in Alaska, detecting it can be a challenge. A normal COVID-19 test doesn’t indicate anything about what variant of the virus a person has. Instead, scientists need to sequence the genome of a viral sample, a process which involves lengthy lab work that isn’t being widely done in most states.
The Centers for Disease Control have implemented no national approach to sequencing viral genomes, instead leaving that task mostly up to the states. While there is currently no data to suggest that the new strain is more lethal than other variants, or that it has any additional immunity to COVID-19 vaccines, the variant is a stark reminder that normally harmless changes in the viral genome can sometimes have large effects, and deadlier and vaccine-resistant variants of the virus could theoretically develop in the future.