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No data on efficacy of Indian Covid vaccines against South African and Brazilian variants: scientists | India News


NEW DELHI: Preliminary research shows that the two Covid-19 vaccines approved in India are effective against the British variant of the new coronavirus, but there is no data on their efficacy against the South African and Brazilian mutants detected in the country.
On Tuesday, the Health Ministry said four people were detected with the South African variant of SARS-CoV-2 and one tested positive for the Brazilian variant, a first for India, prompting scientists to emphasize the need for more. Data and studies so that the country’s vaccine program can adapt to changing demands.
The number of people who tested positive for the UK variant in the country rose to 187, authorities added.
The vaccines currently approved for emergency use in India are Covishield, from the Oxford-AstraZeneca stable manufactured by the Serum Institute of India in Pune, and Covaxin, developed by Hyderabad-based Bharat Biotech, in collaboration with the Indian Council of Medical Research and the National Institute of Virology (NIV).
Answering the main question on many minds, researcher Deepak Sehgal said that it is difficult to say how effective the two will be against the new emerging variants, particularly the South African and Brazilian ones, unless scientists have studied them properly.
“Having said that, between the two vaccines currently in India, Covaxin may work better against the new mutants because it generates protection against the entire virus. The Covishield vaccine targets a single protein of the virus,” Sehgal, head of the department. of Life Sciences, Shiv Nadar University, Uttar Pradesh, told PTI.
Covaxin, he explained, can produce antibodies against many epitopes, or many regions of the whole virus, while Covishield produces antibodies only against a specific region of the virus.
“So even if there is a mutation in one region, antibodies are being produced against other regions of the virus that will be effective in the case of Covaxin,” he added.
Covaxin is an “inactivated” vaccine developed by chemically treating samples of new coronaviruses to render them unable to reproduce. This process leaves viral proteins intact, including the coronavirus spike protein that it uses to enter human cells.
Covishield contains a designed version of adenoviruses that infect chimpanzees to carry the gene responsible for the spike protein of the new coronavirus.
Adenoviruses are common viruses that generally cause mild colds or flu-like illnesses.
Both vaccines claim to have some efficacy against the UK variant.
According to a yet-to-publish study on 26 participants, Covaxin was found to be effective against the UK variant, Bharat Biotech said in late January.
Similarly, a University of Oxford study found that the ChAdOx1-nCoV19 vaccine, known as Covishield in India, was effective in addressing the UK variant.
Immunologist Vineeta Bal noted that the UK variant had only one mutation that mattered and therefore these results were not surprising.
“While the Bharat Biotech results were obtained on a small number of samples to verify inhibition against the UK virus in the current evolving situation, this can be taken as adequate preliminary data,” said Bal from the Indian Institute of Education. and Scientific Research (IISER) of Pune. .
However, both the South African and Brazilian variants have far more mutations, and thus a significant decrease in efficacy can be seen, he said.
“We do not yet have an answer on the efficacy against the new variants. I am sure that efforts are being made to test sera (blood) from vaccinated individuals to determine their ability to block the growth of new variants in the tissue culture system.” Bal said. PTI.
“For that, the virus variant must be available and also the test facility. The NIV, for example, has the competence to do it and I am sure they are trying to test,” she said, adding that there are no results available in the domain. public. yet.
Globally, 10 Covid-19 vaccines have been approved by various countries or have limited emergency use.
New variants of coronavirus are emerging that are more infectious than the one that started the pandemic.
Scientific advisers to the UK government say the Covid-19 variant now prevalent in the country may be 30-70% more “deadly” than previous variants, underscoring concerns about how mutations may change the characteristics of the disease.
A recent study suggests that the vaccine developed jointly by the American pharmaceutical giant Pfizer and the German biotechnology company BioNTech can neutralize variants of the new coronavirus that were first reported in the United Kingdom and South Africa.
The research, published in the journal Nature Medicine, noted that the vaccine is effective against variants of the coronavirus that carry the N501Y and E484K mutations.
In January, the American biotech firm Moderna said laboratory studies showed that its Covid-19 vaccine would continue to protect against variants of the coronavirus first identified in the UK and South Africa.
However, as a precaution, the company will test adding a second booster to its vaccine, for three injections in all, and has begun preclinical studies on a booster specifically for the South African variant.
In the Pfizer and Moderna vaccines, messenger RNA, or mRNA, acts as a blueprint for the production of the coronavirus spike protein and is encapsulated by lipid molecules and delivered to human cells. MRNAs contain a blueprint for making proteins in cells
Rather than the solid published data, it appears that the rapid spread of these emerging variants would reportedly pose some risk to people who have recovered from a previous infection, as well as those who are already vaccinated, Bal said.
“In India, we don’t know how effectively testing, detection and quarantine are implemented for contacts and cases. Depending on that, the spread can be reduced with varying efficiency and hopefully no serious spread will occur. and another round of lockdown will not be necessary, “he added. she added.

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