Vaccine manufacturer Bharat Biotech has recently reported the interim efficacy of its COVID-19 vaccine Covaxin at 81 per cent depending on the large scale human clinical trials conducted by the company.
Vaccine manufacturer Bharat Biotech has recently reported the interim efficacy of its COVID-19 vaccine Covaxin at 81 per cent depending on the large scale human clinical trials conducted by the company. This comes as an important news as people across the country are being given this vaccine among one the two vaccines approved by the government. Before knowing why this comes across as important, it is crucial to understand what vaccine efficacy exactly is.
To be sure, efficacy can be described to what extent, a vaccine shot can protect people against any kind of infection, be it viral or bacterial. This is then compared to the body’s response to the infection when a vaccine is not given. Efficacy can determine how the vaccine will help people be immune to an infection and to what degree- which can be either reducing the symptoms to minimum or completely protecting people from getting that infection.
In cases of Coronavirus, while complete protection may not be given with vaccines, the pharma companies have tried to reduce the number of symptomatic cases significantly. This means that even if someone is infected with COVID-19, the person may not develop symptoms or fall when compared to the infection cases without the vaccine. Therefore, in phase 3 clinical trials of vaccine by Bharat Biotech, the company is studying the impact of Covaxin on 25,800 volunteers across India and is mapping its efficacy.
The data released on Wednesday by the company focuses on how the vaccine has the efficacy of 80.6 per cent. In layman’s terms, the Coronavirus symptoms can be brought down in as many as 81 per cent of the total people vaccinated. Now these results are of much importance as lakhs of people in India are being monitored by this vaccine and a higher efficacy gives clear indication of a higher chance when it comes to protecting the vulnerable population, a report by The Indian Express noted. The data also gives more value to the use of vaccines as many people across the country have been hesitant in taking this vaccine shot. Infact, the company’s Covaxin received major backlash as the government approved it for emergency usage without the complete efficacy data.
As a result, many people were apprehensive in taking the vaccine shot. Well, the apprehensions were justified as until now, no one was really aware regarding the vaccine’s extent for protection. The report citing Dr Gagandeep Kang, vice chair of CEPI and professor at Christian Medical College-Vellore said that with the efficacy data released by the company, people can now be relieved. According to Kang, if the interim analyses show 81 per cent efficacy, the final results will have a higher efficacy rate, which in return is a good sign.
When other vaccines like Covishield are taken in consideration, it was found that this AstraZeneca-University of Oxford’s vaccine has a 53 per cent efficacy when the second dose is administered in less than six weeks after the first dose. However, the developers have noted that when the duration between administration of two doses is increased to 12 weeks, the efficacy improves to nearly 79 per cent. However, in India, 4-6 weeks have been approved for giving the second dose of vaccine.
Further, Covovax- Covid-19 vaccine developed by Maryland, US-based Novavax Inc has an efficacy of around 89.3 per cent in the UK and it is around 60 per cent in South Africa, the report said. Similarly, Pfizer and BioNTech’s BNT162b2 vaccine has an efficacy of around 95 per cent. This is not available in India though. The Coronavirus vaccine made by Moderna and the US National Institute of Allergy and Infectious Diseases (NIAID) has demonstrated an efficacy of almost 94 per cent. Infact, Sputnik V developed by Moscow’s Gamaleya Research Institute of Epidemiology and Microbiology showed an efficacy of 91.6 per cent.
When compared to these, there is no doubt that the efficacy of Covaxin is less. However, the report said that many experts have opined that it is not fair to compare the efficacy of these vaccines as they all are using different platforms and are currently in different clinical trial designs.
Having said this, there is still a lot left that is unknown about Covaxin’s safety and its efficacy related aspects. So far only symptomatic cases are taken in account but Kang said that Bharat Biotech is also looking at prevention among asymptomatic cases as a secondary outcome. There is a need for final results in addition to these interim figures to have a clear understanding about the efficacy of vaccines, Kang added.