Explainer: Are vaccines effective against Delta plus variant of COVID-19?

Hyderabad: A week after the union government called the Delta plus variant of COVID-19 a ‘variant of concern’, inhibitions are on the rise whether the prescribed vaccines against the viral disease will be effective against this variant too.

Declaring the Delta plus variant as a variant of concern, the union health ministry noted three key characteristics i.e. increased transmissibility, stronger binding to receptors of lung cells, and potential reduction in monoclonal antibody response.

Detected in over 11 countries so far, the Delta variant has about 15-17 mutations in the coronavirus and was first reported in October last year. It was responsible for more than 60 percent of cases in Maharashtra in February. Eight states, including Telangana, have now found the delta variant of concern in more than 50 percent of the samples of COVID-19 positive people.

US’ Center for Disease Control and Prevention (CDC) identified six notable variants so far—Alpha, Beta, Gamma, Epsilon, and Delta. However, viruses are always changing; and that can cause a new variant, or strain, of a virus to form. That’s most likely how Delta plus was born, with a slight variation from the Beta or Delta variant.

The evidence around the Delta variant is evolving, and studies now show that current vaccines may not be as effective against it. The World Health Organization (WHO) too said that vaccination is not enough for this variant of concern.

Which India-approved vaccines can work against these variants?

Data from Public Health England have shown that single doses of the AstraZeneca (Covishield in India) and Pfizer vaccines have an efficacy of 33 percent against infections with the Delta variant. Against the original Alpha variant, the efficacy was 85 percent.

Even for those fully vaccinated, the AstraZeneca vaccine also saw a reduction in efficacy—from 67 percent against the Alpha variant to 60 percent against Delta—but not to as alarming a degree.

The PHE also found that both these vaccines were over 90 percent effective in reducing hospitalizations and serious disease.

Besides, the Indian health ministry also stated that the indigenously-made Bharat Biotech’s Covaxin is effective against the Delta variant. Though it did not provide any data to back its claim, it said that the extent and proportion of antibody titers produced by both Covishield and Covaxin will be shared soon.

Also, Russian-made Sputnik V has also been said to be effective against all variants of COVID-19 known today. As per Gamaleya Centre head Alexander Gintsburg, “Antibodies developed after vaccination with Sputnik V protect from all variants of COVID known today, starting from the UK variant to the so-called Delta variant, first detected in India.”

Pfizer/BioNTech, which is in talks with the Indian government over supplies of its COVID-19 vaccine, which is also said to be effective against the COVID-19 variants.

“Very recently we have cultured the delta plus variant, and now we are testing in the laboratory whether the vaccine are effective against the delta plus variant. We have enough data against alpha, beta, and delta… and we are doing the same laboratory tests on this variant that we did on others; it is called looking the laboratory tests to check the vaccine effect. This is ongoing and we should have results in about seven to 10 days time,” said ICMR director general Dr Bhargava.

Major concerns

Experts have flagged concerns regarding the efficacy of vaccines against this variant, which can lead to a further rise in the number of cases.

As quoted by Hindustan Times, one of India’s top virologists Professor Shahid Jameel said that the new mutant variant may just be capable of dodging immunities, both from COVID-19 vaccines as well as from earlier infections. This is because the Delta plus variant not only has all the symptoms that the original Delta variant had, but also carries symptoms from its partner Beta variant.

Experts said that Delta plus can likely inflict another wave of infections on India, after it emerged from the world’s worst surge in cases only recently. So far 48 cases of the variant have been reported so far from 10 states. Four deaths have been attributed to Delta plus in Madhya Pradesh, Maharashtra and Tamil Nadu.