National

#IndiaFightsCorona : Covaxin And Covishield Battle It Out For Efficacy

According to Lancet, the medical journal, the homemade Covid-19 vaccine, Covaxin, is safe, immunogenic and has no serious side-effects. Covaxin is one of the two vaccines being used in India’s mass vaccination programme against Covid-19. A higher efficacy would mean a higher chance at protecting the vulnerable population against the disease.
According to Bharat Biotech’s interim results, the vaccine has an efficacy of 80.6 per cent. This means the vaccine was able to bring down the number of symptomatic Covid-19 cases by nearly 81 per cent in those vaccinated in the trial as compared to the group that received a placebo. The results were collected by studying 43 participants in the trial who had tested positive for Covid-19 two weeks after receiving their second dose, and had presented with mild, moderate, or severe symptoms. The trials were unblinded at this point to check how many of these participants had received Covaxin and how many had got a placebo. It was found that 36 out of these 43 participants had received a placebo, while seven had received Covaxin. These results have so far not been published in a scientific journal.

The findings are expected to add value to the vaccine and ease hesitancy related to it. The vaccine had earlier come under fire for having received emergency approval without Bharat Biotech recruiting and vaccinating enough participants in its phase 3 trial to even provide an idea of its efficacy. This meant, until now, no one knew how much protection this vaccine would actually be able to provide to those receiving it.

“It’s a bit of a relief,” said vaccine expert Dr Gagandeep Kang, vice chair of CEPI and professor at Christian Medical College-Vellore. “The interim analyses actually test the vaccine much more, so if it has around 81 per cent efficacy, then that means it is likely to maintain a high level of efficacy even when the full results are released,” she said.

On the other hand, Covishield, the other vaccine being used in the government’s campaign, has an efficacy of around 53 per cent when the second dose is given less than six weeks after the first dose, according to its product insert. However, the efficacy of this vaccine, which is based on the AstraZeneca-University of Oxford jab AZD1222, varies based on the duration between the first and second shots. According to Covishield’s product insert, this efficacy changes to nearly 79 per cent if the second dose is administered at 12 weeks or longer. At the same time, as per the regulatory approval to Covishield as of now, the second dose has to be given 4-6 weeks after the first dose.

Till now over 2.4 crore people have been vaccinated. Of this 82% were first doses to health and frontline workers along with those above 60 years of age and between 45-60 years with specified co-morbities. The rest were given as second dose to the health and frontline workers.

To Top