Representational Image


India may require the third dose of the COVID-19 vaccine by the middle of next year, said eminent scientist and biochemist Prof G. Padmanaban, as breakthrough cases after complete vaccination, although mild, have been prevalent.

Prof. Padmanaban, Chancellor of the Central University of Tamil Nadu and a Padma Bhushan recipient, said his opinion on a third dose is based upon scientific understanding.

“In an infection by the Delta variant, which is widespread, there is a six-eight fold drop in the potential of antisera from vaccines to neutralise the variant compared to the wild type (used for vaccination- spike or whole virus).

“Nobody still has a clear answer to how long the protective antibodies will last; it has been variably estimated to be between six months and one year. If the virus has not weakened by itself, by that time, there is possibility for a re-infection,” he said.

As scientists’ understanding of cell-mediated protection (cellular immunity and humoral immunity) is still evolving in the case of COVID, “a third dose (sometime mid to late next year) by mix and match also gives an opportunity to give a different vaccine against the variant,” he noted.

The US Centers for Disease Control and Prevention defines a vaccine breakthrough infection as the detection of SARS-CoV-2 RNA or antigen in a respiratory specimen collected from a person more than 14 days after completing all recommended doses of an authorised COVID-19 vaccine.

Globally, many studies and scientists have claimed that two doses of a COVID vaccine are sufficient for preventing infection, hospitalisation and death by the SARS-CoV-2 virus.

However, the Delta variant, which has now spread to more than 185 countries, as per the World Health Organisation, renewed the debate for COVID vaccine boosters. Israel, one of the first countries to fully inoculate (two doses) the majority of its people, suffered severely due to the Delta variant. It again became one of the first countries to roll out a third dose for its citizens.

“As far as the variants are concerned, the Delta variant is not the end of the story. The larger question is—do we have the vaccine for every variant being created? Perhaps not. Thus, I feel that by the middle of next year, India may need the third dose of vaccine,” Padmanaban, the former Director of Indian Institute of Science, said at a weekly health show by the New Delhi-based HEAL Foundation.

While many countries, including the US, the UK, France, and Germany, have rolled out COVID boosters, India is still weighing its need.

Scientists at the Indian Council of Medical Research (ICMR) have not approved a booster dose yet in India. For India, a booster dose is not the central theme at the moment and getting two doses remains the foremost priority, media reports quoted ICMR Director General Balram Bhargava as saying.

Countries that rolled out boosters first gave the third dose to the elderly, majorly above 70, and people with weaker immune systems. However, the Indian experts state that there is no need for booster doses in India as enough study has not been done on the subject.

Padmanabhan said: “It is essentially a case of demand and supply. We are still not able to make enough doses to vaccinate all above 18 years. We would need 1,500 mn doses (two jabs) for 75 crore population. We have only reached, perhaps, 25% (two doses).

“If this population has to be vaccinated by December, we need to make at least 300 mn doses per month.”

India currently has four vaccines: Covaxin, Covishield, Sputnik V and ZyCoV-D. However, Sputnik and Zydus Cadila’s vaccine production needs to be scaled up.

The other two vaccines expected in India are an mRNA vaccine by Gennova Biopharma, a subsidiary of Pune-based Emcure Pharmaceuticals, and a Recombinant RBD vaccine by Biological E, Hyderabad.

“If all these become a reality, hopefully, we can vaccinate 75 crore population before March (two doses). Giving a third dose to above 70 can only then be considered. In the meanwhile, children aged 2-18 have become another segment. Public health experts have to decide,” said Padmanaban.

The 83-year-old scientist said in his opinion, “the SARS-CoV-2 virus has weakened, and even if there is a third wave, it is likely to be mild”.

But the probability of SARS-CoV-2 visiting us every year, like the flu virus, can only be a “speculation” at this stage, he said.

“This tiny virus has challenged the scientists, despite our claim of huge scientific and technological progress, a lesson in humility!” he remarked.


The above article has been published from a wire agency with minimal modifications to the headline and text.



Please enter your comment!
Please enter your name here