Should we worry about Delta Plus?

PTI06_26_2021_000029A Chasing delta plus: A medical team on a door-to-door survey in Bikaner, Rajasthan | PTI

It was the dominant villian in the second wave of Covid-19 across much of India. Then, it put a spanner in the UK’s reopening plans and now accounts for almost all its new infections. The European Union fears it may account for 90 per cent cases in its region by the end of August. The Delta variant of the SARS-CoV-2 virus turned out to be a nighmare within a nightmare. Now, the wily virus has released an updated version, a plus factor. There is no doubt that evil lurks within Delta Plus, as it is the spawn of Delta, the most transmissible variant of concern (VoC). But is the son worse than the father?

Delta Plus has been around for some months. Its earliest sequencing was done by Indian scientists in April, just when the second wave was rising. It is present in several countries, but not as widely as Delta (over 90 countries). It has Delta's high transmissibility and greater affinity to the receptor cells in the lungs. In addition, it has the K417N mutation in its spike protein. This mutation occurs when the amino acid lysine is replaced by aspargine in the 417th position in the protein. The same mutation had occurred in the Beta and Gamma variants, first sequenced in South Africa and Brazil, respectively. Anurag Agarwal, director, Institute of Genomics and Integrative Biology, believes this to be a case of “convergent evolution”—the same mutation has developed independently in different geographies.

The Indian SARS-CoV-2 Consortium on Genomics says K417N may have immune escape properties and reduce antibody response. “This suggestion is purely on the basis of the genomic structure; it is still being studied in epidemiological terms,” says Sujeet Kumar Singh, director, National Centre for Disease Control.

The scientific community has not rung alarm bells yet. But it does not mean that Delta Plus will not turn a bigger villain later. It wasn’t too long ago that people were introduced to the “double mutant”, now rechristened Delta. Epidemiological studies take time to be presented. But Agarwal believes Delta Plus may not cause much worry in populations where Delta is dominant.

So far, 51 Delta Plus cases have been identified in 12 states, mainly Maharashtra. As V.K. Paul, member of the national task force on Covid-19, says, these cases may already have recovered, given the lag between case identification and genomic sequencing. The states are already tracing their contacts, testing them and isolating them. While there is no need for a panic, smugness and slackness have no place, either.

Newer variants of interest (VoI) are emerging. A VoI is a notch below VoC. The Lambda variant, first seen in South America, has created a first ripple in the UK. It is not yet seen in India. With travel opening up over time, these variants might come over. Also, the virus could mutate into newer VoCs in India itself. At a time when India is opening up after its second lockdown, are these emerging variants a worry?

Experts insist that the same protocol of Covid appropriate behaviour works against all variants—social distancing, masks and hand hygiene. Vaccines, while not impenetrable, do provide an armour, reducing chances of severe disease, hospitalisation and death. Even Delta Plus's potential trick of reducing antibody response may not matter much, because vaccines target several sites on a virus; a single mutation doesn’t stand much chance

The future hinges on wider vaccine coverage. India seems to be on the right track. Having done 32 crore jabs, India has surpassed the US on the vax top chart. Nearly half its senior citizens have got at least one shot. More importantly, the rural-urban coverage of 56:44 per cent closely resembles the population distribution in the country. The gender ratio is still skewed against women, and vaccine hesitancy continues to be a challenge.

“Ramping vaccine production and getting new vaccines are important to sustain this tempo, and work towards the goal of one crore vaccinations a day,” says Oommen Kurian of the Observer Research Foundation.

The government has approved the American vaccine Moderna, which will be imported through its Indian partner, Cipla. It has projected availability of 216 crore doses, of different vaccines, during August-December. Their delivery and administration will decide how India ushers in 2022.