The ongoing spread of the SARS-CoV-2 virus has spawned a series of strain names in the Greek alphabet through a naming system used by the World Health Organization to track alarming new mutations in the virus that causes COVID-19. Some of these mutations have provided the virus with a better means of transmitting infection to humans or of circumventing the protection offered by vaccines. </p><div> <p>Scientists are still focused on the delta of the now-dominant strain, which is spreading like wildfire around the world, but they are following other strains to see what might one day take its place.
The Delta breed, first spotted by scientists in India, remains the most concerning. It infects large numbers of non-vaccinated people in many countries and has proven its ability to transmit infection to numbers of vaccinated people greater than its predecessors.
The World Health Organization classifies Delta as a strain of concern, meaning that it has proven its ability to spread rapidly and cause more severe cases or reduce the benefits of vaccines and treatments. Shane Crotty, a virologist at the La Jolla Institute for Immunology in San Diego, says the Delta strain’s “superpower” is its ability to spread.
Chinese researchers have found that the number of viruses in the noses of people with the Delta strain is 1260 times more than the original version of the Corona virus. Some American researchers indicate that the “viral load” of vaccinated individuals who contracted delta infection is equal to the viral load of those who are not immunized, but more research is needed.
Although the original Corona virus needs up to seven days to cause symptoms, in the Delta strain, symptoms can appear two or three days earlier, allowing the immune system a shorter period to respond and set up defenses. The Delta strain also appears to be mutating, with reports emerging of a “Delta Plus” strain that can evade immune protection.
In June, India classified Delta Plus as a strain of concern, but the US Centers for Disease Control and Prevention and the World Health Organization have yet to do so. Outbreak.info, an open database of Covid-19 disease, says Delta Plus has been detected in at least 32 countries. Experts say it is not yet clear whether this strain is more dangerous.
Lambada – a breed in decline?
The lambda strain has attracted attention as a potential new source of danger. However, this version of the Corona virus, which was first discovered in Peru last December, appears to be receding, according to what a number of infectious disease experts told Reuters. The World Health Organization classifies lambda as a strain of interest, meaning that it carries mutations that appear to enable it to alter the ability to spread or cause more severe disease. But it is still being researched. Laboratory studies show that it has mutations that resist antibodies stimulated by vaccines.
Eric Topol, professor of molecular medicine and director of the Scripps Research Institute in La Jolla, California, said the percentage of new lambda infections detected in the GISAID database that tracks virus strains is declining. In an indication that the breed is in decline. In a recent conference call with the Centers for Disease Control and Prevention, disease experts said lambda did not appear to be causing an increase in spread, and Dr. William Schaffner, an infectious disease expert at Vanderbilt University Medical Center who participated in the conference, said vaccines appeared to be able to defeat it.
B.1.621..a strain worth watching
No name has yet been assigned to the Greek alphabet for the strain B.1.621 that first appeared in Colombia in January and caused a large-scale outbreak of the disease. The European Center for Disease Control and Prevention has classified this strain of interest while Public Health England describes it as a strain under investigation.
This strain carries a number of major mutations, including E484K, N501Y, and D614G, which have been linked to increased proliferation and reduced immune protection. So far, 37 confirmed and probable cases of this strain have appeared in Britain, according to a recent government report, and this strain has also been discovered in a number of patients in Florida.
More on the way?
Dr. Anthony Fauci, the White House’s chief medical advisor, recently warned that the United States may face problems unless more Americans are vaccinated, because the presence of a large number of unvaccinated people gives the virus a greater chance of spreading and mutating into new strains. Advocates of the need for rich countries to distribute more vaccines worldwide say that the same may happen with the emergence of new strains unchecked among the population of poor countries where only a small number of people received the vaccine.
However, Dr. Gregory Poland, an expert in vaccines at the Mayo Clinic, said one of the main problems is that current vaccines prevent severe cases of disease but do not prevent infection.
This is because the virus is still able to replicate itself in the nose, even among those vaccinated, who can then pass the disease on to others. Poland added that to defeat the SARS-Cove-2 virus, it is likely that a new generation of vaccines will be needed, which can also prevent the spread. Until then, the world will remain vulnerable to the emergence of new strains of the Corona virus, according to the views of Poland and other experts.