Beyond Delta, Scientists See New Variants Of The Coronavirus

The continued spread of the SARS-CoV-2 virus has resulted in the creation of a Greek Alphabet of Variants, a naming system used by the World Health Organization to track new mutations in the virus that causes COVID-19 .

Some have provided the virus with better ways to infect humans or evade the protection of vaccines.

Scientists remain focused on Delta, which is the dominant variant that is growing rapidly in the world, but they are following others that may one day take its place.

DELTA

The Delta variant, first detected in India, remains the most worrying. It affects unvaccinated populations in many countries and has been shown to infect a higher proportion of vaccinated people than its predecessors.

The WHO classifies Delta as a variant of concern, which means it has been shown to be able to increase transmissibility, cause more serious disease, or reduce the benefits of vaccines and treatments.

According to Shane Crotty, a virologist at the La Jolla Institute of Immunology in San Diego, Delta’s “superpower” is its transmissibility. Chinese researchers have found that people infected with Delta carry 1,260 times more virus in their noses than the original version of the coronavirus.

Some US research suggests that the “viral load” of vaccinated people who become infected with Delta is comparable to those who are not vaccinated, but more research is needed.

While the original coronavirus took up to seven days to cause symptoms, the Delta may do so two to three days earlier, giving the immune system less time to respond and defend itself.

Delta also appears to be mutating further, with reports emerging of a “Delta Plus” variant, a subline that carries an additional mutation that has been shown to escape immune protection.

India listed Delta Plus as a variant of concern in June, but neither the US Centers for Disease Control and Prevention nor the WHO have yet done so.

According to Outbreak.info, an open source COVID-19 database, Delta Plus has been detected in at least 32 countries. Experts say it’s not yet clear if it’s more dangerous.

LAMBDA: FALLING?

The Lambda variant has gained attention as a potential new threat. But this version of the coronavirus, first identified in Peru in December, could regress, several infectious disease experts told Reuters.

The WHO classifies Lambda as a variant of interest, which means that it carries mutations suspected of causing a change in transmissibility or causing more serious illness, but is still under investigation. Laboratory studies show that it has mutations that resist the antibodies induced by the vaccine.

Dr Eric Topol, professor of molecular medicine and director of the Scripps Research Translational Institute in La Jolla, Calif., Said the percentage of new Lambda cases reported to GISAID, a database that tracks variants of SARS – CoV-2 , decreased, indicating that the variant is regressing.

In a recent call with the CDC, disease experts said Lambda did not appear to cause an increase in transmissibility and the vaccines appeared to hold up well, said Dr. William Schaffner, an infectious disease expert at the Medical Center. from Vanderbilt University. who attended the discussion.

B.1.621

The B.1.621 variant, which first appeared in Colombia in January, where it caused a major epidemic, has yet to gain a letter in the Greek alphabet.

The European Center for Disease Prevention and Control has listed it as an interesting variant, while the UK Department of Health describes B.1.621 as an experimental variant. It carries several key mutations, such as E484K, N501Y, and D614G, which have been linked to increased transmissibility and reduced immune protection.

So far, there have been 37 probable and confirmed cases in the UK, according to a recent government report, and the variant has been identified in several Florida patients.

IS THERE MORE ON THE WAY?

Dr.Anthony Fauci, chief medical adviser to the White House, recently warned that the United States could be in trouble unless more citizens are vaccinated, as a large group of unimmunized people give the virus more scope. to spread and mutate into new variants.

Advocates of greater international distribution of vaccine doses by rich countries say the same could happen, as variants uncontrollably emerge among populations in poor countries, where very few have been vaccinated.

Yet a key problem is that current vaccines block serious disease but do not prevent infection, said Dr Gregory Poland, vaccine scientist at the Mayo Clinic. This is because the virus is still able to replicate in the nose, even in vaccinated people, who can transmit the disease through tiny aerosol droplets.

To beat SARS-CoV-2, he said, a new generation of vaccines that also block transmission will likely be needed. Until then, the world will remain vulnerable to the emergence of new variants of the coronavirus, according to Poland and other experts.