International 29/04/2021

No evidence that Indian variant of coronavirus is resistant to vaccines

Recent studies suggest that vaccines are effective against the British, South African and Brazilian variants

3 min
Members of a family embrace amidst burning pyres of victims who lost their lives to Covid-19 at a cremation centre in New Delhi

The world watches with concern as covid is wreaking havoc in India. In addition to shocking figures and images, from the Asian country comes the information that there is a variant of the virus that accounts for 60% of the sequences analysed. The WHO has issued a statement on this variant known as B.1.617, which for the moment is considered as a variant of interest, that is to say, to be studied in detail. Other variants, such as the so-called South African, Brazilian and British (which already represents more than 90% of the samples sequenced in Catalonia), have long been classified as variants of concern because, among other things, they are more transmissible than the virus identified in Wuhan.

The WHO notes that the "interest" of this variant lies in the fact that it has two of its 13 mutations in the S protein, the spicule that the virus uses to infect cells. The first, called L452R, is shared with the so-called California variant, which, according to a study recently published in the Cell journal, may be 20% more contagious than the original virus (the British variant is considered even more transmissible). In the same way, the WHO notes in the statement that according to one of its mathematical models, data from India suggest that the B.1.617 variant could be more transmissible than the original, but does not specify what percentage. The other mutation, called E484Q, is very similar to a variation shared by the South African and Brazilian variants, which have been shown to evade some monoclonal antibodies. These antibodies are used as a treatment, especially in the United States, and are called monoclonal because the drug administered is made up of only one type of antibody. This mutation, therefore, can make some of these treatments not work. However, the immune response produced by a natural infection or a vaccine generates many more types of antibodies. Therefore, the fact that monoclonal antibodies are not effective does not mean that the much richer immune response fails to neutralise the B.1.617 variant.

The WHO also notes that variants that share mutations with the Indian variant have moderately reduced the ability of the blood plasma of vaccinated people to neutralise the virus. This had already been observed in the variants from South Africa and Brazil. However, what happens to plasma in a laboratory culture is one thing, and what happens inside the body during an infection is quite another. A study published in the New England Journal of Medicine shows that the Pfizer vaccine is effective against the British, South African and Brazilian variants. Other studies have found the Moderna, AstraZeneca and Janssen vaccines to be effective as well. Although the latter two are somewhat less effective, they have been found to provide a good level of protection against severe disease against these variants. It is therefore likely that the results with the Indian variant will be similar.

In addition, when assessing laboratory experiments with plasma, it must be taken into account that there are antibodies but no T-lymphocytes in the plasma. The first studies are always done this way because it is cheaper and faster. T-lymphocytes, however, are the body's main defence against viruses. If the antibodies, in the first phase of the immune response, block the virus and prevent it from infecting cells, the T lymphocytes locate the infected cells and destroy them. A study that has not yet been published in any journal but is done by one of the best immunology research groups in the world showed a few weeks ago that the T-lymphocytes generated during natural infection or by the Pfizer and Moderna vaccines were effective against all variants. It is therefore likely that they are also effective against the Indian variant.

Although the effect of the vaccines on this variant is just beginning to be studied, a paper has already been uploaded to the BioRxiv online repository. The study, of course, has not yet been published in any scientific journal. Despite having only 45 samples, the conclusions point out that both the plasma of patients who have passed the disease and that of people immunised with the Covaxin vaccine, developed in India from an inactivated form of the virus, are able to neutralise the B.1.617 variant in laboratory cultures.

So far, therefore, there are no data indicating that the vaccines are ineffective against the Indian variant. Nor are there any that support a higher transmissibility or aggressiveness of this variant compared to the so-called worrying variants, one of which, let's remember, is dominant in Catalonia. With the data currently available, the most plausible explanation for the catastrophic situation in India has more to do with social causes than with the biology of the virus. As has been seen in other parts of the world, high population density, poverty, poor nutrition, poor adherence to social distancing measures, hygiene and use of masks, as well as a low percentage of vaccinated population, favour the spread of the virus and the severity of the disease.