The Delta variant of the coronavirus spawned a strain of its own that is gaining considerable attention these days since being dubbed “Delta-plus” in India.
It is a slightly different variant of the original Delta, which was also first identified in that country. The latter is regarding twice as transmissible as other strains of the coronavirus, meaning unvaccinated people are more likely to become infected if exposed.
Britain was forced to delay a new phase of reopening its economy when the variant began to spread among unvaccinated people there, once more leading to a surge in cases and hospitalizations.
Delta contagion is an obvious cause for concern. But what regarding the Delta-plus?
According to statements issued by the Indian government, Delta-plus features also include increased transmissibility. But it’s not clear if the strain is even more transmissible than the regular Delta variant.
For California scientists, there is not enough evidence to suggest that Delta-plus is more of a problem than the original Delta. “It has a good name,” said Dr. Benjamin Pinsky, director of the Laboratory of Clinical Virology at Stanford University. But there isn’t much information available to suggest it’s worse than anything else out there, and more research is needed, he said. “Sounds like another variant that is no better, or worse, than the regular Delta. It’s not clear why everyone is pushing the issue,” said Dr. George Rutherford, an epidemiologist at UC San Francisco. “I don’t see it being a big problem right now. I mean, it can get complicated; can become a major inconvenience. But certainly there is nothing observable that I am unduly concerned regarding at this time.”
Dr. Monica Gandhi, an infectious disease expert at UC San Francisco, noted that the lack of data on Delta-plus is due, in part, to limited genomic surveillance in India due to underfunding.
“I don’t think much can be known yet, from the data we have, if it is really more transmissible or not,” he remarked.
While the world remains concerned regarding increasingly contagious variants, according to some experts, at some point there will be a limit to transmissibility. Scientists do not expect this coronavirus to be as transmissible as measles, one of the world’s most contagious pathogens. “I know it still seems like more and more, so it’s certainly understandable that people are wondering, ‘Why doesn’t it stop?’” Gandhi said. “Once transmission is reduced, it will really stop accumulating mutations… That’s why we want, of course, global equity in vaccines: to stop transmission.”
The rise of more transmissible variants is understandably concerning to scientists and public health experts. With the initial strains of coronavirus, it might take 71% of the population to be immune for a region to reach “herd immunity,” in which ongoing transmission of the virus is interrupted, Rutherford explained. But a more transmissible version, like the Delta, would require raising that threshold, perhaps to 84%, he said. “Viruses mutate all the time,” he stressed. As far as Delta-plus is concerned, “they haven’t really figured out if it’s much worse or if it’s a new threat,” Rutherford added.
Health officials have already issued warnings regarding the original Delta variant, which has gained a significant foothold in some areas of the United States. From May 9 to 22, it accounted for less than 3% of the genomically sequenced coronavirus samples nationwide. But from June 6 to 19, that share rose to more than 20%, according to figures released last week.
Dr. Anthony Fauci, the US government’s top infectious disease expert, called the strain “currently the greatest threat in the United States to trying to eliminate COVID-19.”
The proportion of coronavirus cases caused by the Delta variant recently increased in California, where it is known to have infected 372 people, according to figures from the state Department of Public Health.
According to the latest data, Delta is now the third most common variant in California, accounting for 14.5% of cases analyzed in June. The Alpha variant, identified for the first time in the United Kingdom, is found in 37.7% of the cases analyzed, and Gamma, identified for the first time in Brazil, is in 21.6%.
The data shows that the Delta variant is increasing its proportion of coronavirus cases in California, which are the lowest since the first weeks of the pandemic, 15 months ago.
In May, only 4.7% of coronavirus cases tested were Delta, and it was the fourth most identified variant in the Golden State. That month, Alpha accounted for the majority of genomically sequenced cases in the state, at 58.4%, while Gamma was booked in 10.1% of episodes.
A variant first recognized in New York, B.1.526.1 (no Greek letter assigned), was identified in 5% of analyzed cases.
The most populous county in the country, Los Angeles, confirmed 123 cases of the Delta variant, 49 of them among residents of Palmdale and Lancaster. For the director of Public Health of the county, Bárbara Ferrer, that number “has occurred between mid-April and now”, for which “you can see that we have had a large increase in the circulation of the Delta variant.” But, he continued, “if you are fully vaccinated, there is a lot of protection. In the case of that small number of people who got sick, even with their applied doses, they did not actually present a serious condition, ”said the official.
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