In recent weeks, two major strains of the COVID-19 virus have appeared, increasing concerns about their contagiousness and testing accuracy. Still, neither is more harmful than the virus circulated over the last year, experts claim, and vaccinations available should remain successful.
"COVID-19 research laboratories should track samples for mutant forms of the virus throughout the U.S.", the Food and Drug Administration said Friday. The agency cautioned that there is a risk that the mutations will trigger certain studies to return false-negative findings. Still, it is doubtful that any tests will fail infectious individuals.
The virus has evolved several times in more than a year of circulation. Still, only these two most recent variants seem to make a significant difference in its work, which first emerged in the United Kingdom and the other in South Africa.
Here's what we really believe about these new mutants.
So what are the versions?
Since it emerged in China in late 2019, scientists have tracked several mutations of Sars-CoV-2, the strain that triggers COVID-19.
The overwhelming number of mutations did not change either the virulence or transmissibility of the virus materially.
However, according to Imperial College London, B117 from southeastern England has now been found in nations worldwide, including the United States, France, and India.
Experts found 501.V2, the South African variant, in October. The strain has since spread to many nations, including Britain and France.
Both contain several viral mutations, most prominently on their spike protein-the portion of the virus that latches and helps transmit to human cells.
Specifically, the mutant forms have a modified receptor binding domain identified as N501Y found on the protein spike of the virus, which enables better entry in human cells to the ACE2 receptor.
This theoretically makes the mutant forms more contagious than other varieties.
According to the European Centre for Disease Control (ECDC), although there is no direct correlation between increased ACE2 binding and increasing transmissibility, there may be such an association.
Are They More Infectious?
Indeed, some recent reports have concluded that the British Sars-CoV-2 version is likely to be even more infectious than other strains.
The NERVTAG advisory group that advises the British government on disease prevention says the latest mutation is predicted to be 50 percent to 70 percent more transmissible.
Although initial evidence suggests that the two latest variants are more infectious, caution has been recommended by experts.
Bruno Coignard, head of infectious diseases at France's Sante Publique France health authority, advised AFP that the British version's outbreak was attributed to a mixture of causes.
He said these involve the virus's attributes and the mechanisms set in a place for prevention and control.
Are They More Harmful?
There is little proof at present to indicate that the mutant viruses are much greater than natural.
But improved transmissibility alone presents an enormous challenge, provided that hospital treatment is needed for a limited but constant proportion of COVID-19 patients.
Increased transmissibility inevitably results in a much higher rate of incidence, which, also with the same mortality, indicates a greater burden on health services, Coignard added.
Adam Kucharski, an LSHTM epidemiologist, said that a 50 percent more infectious virus would be an "even greater issue" than one that is 50 percent more harmful.
He clarified in a Twitter thread how a disease such as COVID-19 would be predicted to cause 129 deaths within a month with a replication (R) rate of 1.1, where each patient infects 1.1 others on average, and a mortality rate of 0.8 percent.
The number of fatalities would rise to 193 if the mortality rate grew by 50 percent.
But an illness with a 50 percent higher infection rate will see the death count reach 978 owing to the rapid rise of cases of a more infectious version.
Why a SARS-CoV-2 variant that's 50% more transmissible would in general be a much bigger problem than a variant that's 50% more deadly. A short thread... 1/
— Adam Kucharski (@adamjkucharski) December 28, 2020
What Should Be Done?
Coignard said it was difficult to eliminate the latest viral forms totally, but policymakers' target could be "maximum delay" in transmitting them.
The ECDC says that initiatives to slow the transmission should reflect those produced during the pandemic's initial phases in countries still untouched by the latest mutations.
The steps involve new arrival checking and quarantining, touch tracking, and restricted travel, it said.
By sheer luck, experts can identify the British version by some current PCR checks.
Therefore, by rigorous research, Fontanet proposed "extremely aggressive surveillance."
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