Last month, the Indian government detected a new mutation in the Delta coronavirus variant, prompting it to classify it as a variant of concern.
The Indian Ministry of Health thus classifies a variant as soon as there is evidence of increased transmission.
The new variant, known as “delta plus,” AY.1 or B.1.617.2.1, has an extra mutation in the spike protein of the SARS-CoV-2 virus, the virus that causes covid-19.
This mutation was found in samples from 48 people infected with the delta variant in India, out of more than 45,000 samples.
So how is this variant different? And another question: Can you escape the protection of the vaccine?
What is the delta variant?
The more infectious delta variant of the coronavirus has spread around the world and is on its way to becoming the dominant strain, according to the World Health Organization.
This variant has been the dominant strain that caused the second wave in India.
Studies have found that it can replicate faster, spread more easily, and bind more strongly to receptors on lung cells.
Also, in a study not yet peer-reviewed, the Delhi researchers found that the variant caused three-quarters of infections in people who have been vaccinated. About 8% of these late-breaking infections had the Kappa variant, and 76% the Delta variant.
How is the “plus” variant different?
The new delta variant mutation was first detected in Europe in March.
In June, covid-19 patients in India were also found to have the mutant virus. These events have raised concern.
Some scientists in India fear the mutation could fuel another wave of infections in the country.
However, the mutation in the spike protein of the virus is not new. Known as “K417N”, it has been previously reported in the beta variant first found in South Africa. The beta variant with this mutation has shown an ability to escape the antibodies conferred by vaccination, at least to some extent. In other words, there is a possibility that vaccines do not protect against this mutation as effectively.
Will delta plus vaccines work?
According to the Indian Ministry of Health, delta plus could have a similar ability to evade immunity and an ability to reduce the effect of monoclonal antibody therapies used to treat COVID-19.
The mutation is worrisome because it is located in a key portion of the virus, the spike protein, used to penetrate human cells.
Previous mutations were in the spike’s “receptor-binding domain”, which allows the virus to bind to receptors on our cells.
The unique mutations of the delta variant allow the virus to escape the immune system to some extent. In fact, delta has been shown to reduce the effectiveness of vaccines somewhat. This means that a single dose of the vaccine may offer reduced protection.
However, a second dose has been shown to produce sufficient antibodies against symptomatic infection and severe disease. It is important to remember that most COVID-19 vaccines do not provide absolute sterilizing immunity, but instead act to reduce the severity of the disease.
UK researchers found that Pfizer’s vaccine was 33% effective against delta after a single injection, and 88% after both doses. For the AstraZeneca vaccine, the efficacy was 33% after the first dose, and it rose to 60% after the second.
The delta plus variant could have a similar degree of efficacy reduction versus the vaccines currently in use. Although good data has not yet been seen on whether this is so.
Studies are underway in India to evaluate the efficacy of Delta plus vaccines.
It is important to note that delta plus has not yet taken off substantially, and the World Health Organization has not yet classified it as a worrying variant.
What should we do now?
Variants with higher transmissibility and the ability to escape antibodies pose a threat to efforts to control and mitigate the pandemic. And countries with low vaccination rates may face new outbreaks.
How should our answer change? Despite the mutations, no additional special measures are necessary. We must continue to vaccinate the maximum number of people, increase genomic surveillance to follow the evolution of the virus and follow an appropriate behavior against covid-19.
Sunit K. Singh, Professor of Molecular Immunology and Virology, Institute of Medical Sciences, Banaras Hindu University
This article was originally published on The Conversation. Read the original.
