For the third phase of the vaccine in which 25,800 subjects were involved, it was the ever largest conducted in India.
Covaxin is one of the vaccines that are being used in the mass vaccination program of India by Bharat Biotech. As reported by Bharat Biotech there is around 81% interim efficacy for Covaxin, in large-scale clinical human trials.
With two full doses, the AstraZeneca-Oxford vaccine has shown 62% efficacy and 90% efficacy in one and a half and one full-dose regimen. Sputnik V, a Russian vaccine has shown the efficacy of 91.6% in analyzing data from 19,866 volunteers.
What is meant by “efficacy” of a vaccine?
Efficacy is the measure that how much shot is the protection for the people against a bacteria or a virus. It is compared to a situation in which they were not vaccinated.
In other terms, it can be said that efficacy shows the prevention ability against a pathogen as compared to the absence of vaccination.
In the case of Covaxin, the efficacy is 81%, which means that the vaccine was able to fight COVID-19 in 81% of people who received it during the period of trial.
The ability of the vaccine for the protection of inoculated population using different parameters is the ability under efficacy. It ranges from the efficiency of the shot to prevent symptoms that are mild to severe from showing if you have been infected.
In such cases of COVID-19 vaccines, the concentration of the pharmaceuticals companies is on lowering the number of symptomatic cases. Even if you got infected with SARS- CoV-2, you might not present with the signs and fall as sick as you could have without taking the vaccination.
What do the Covaxin interim data mentions?
As per the results of interim, the vaccination has the efficacy of 80.6%. It concludes that the vaccine lowered the number of symptomatic COVID-19 cases by almost 81%. This data is related to those vaccinated in the trial in comparison to the group that got a placebo.
These results were collected by analyzing 43 participants in the trial who were tested positive for COVID-19 just two weeks after receiving the second dose. They were presented with mild, moderate, or severe symptoms. It was noticed that 36 out of 43 participants got received a placebo and 7 received Covaxin.
The consequences have so far not been published in any scientific journal.
Why the results declared on Wednesday were so crucial?
Covaxin is one of the two vaccines that is being used in the Mass Vaccination Program of India for Coronavirus. Higher efficacy implies more chances for the protection of the population against the pandemic virus.
The conclusions are anticipated to add value to the vaccine and ease the hesitancy related to it. Earlier the vaccine come under fire for having emergency approval without Bharat Biotech recruiting and vaccinating many participants in the trial of the third phase to give an estimation of its efficacy. It can be said that it is unclear that how much protection this vaccine can provide.
According to the expert, Dr. Gagandeep Kang, professor at Christian Medical College, “It is a bit of a relief”. The interim analysis examines the vaccine, if it has 81% efficacy, it implies that it is predicted to maintain a higher level of efficacy.
Shall we compare the efficacy of vaccines?
For this point, there is a disagreement. Many professionals feel it could not be justified to compare vaccines using distinct clinical trial designs and platforms.
The data that was released is just based of 43 cases of Coronavirus, in the case of Covaxin. It is expected by Bharat Biotech to get a vivid picture of its efficacy when 130 cases get accumulated among the participants.
However, it is not complete information, unlike the AstraZeneca vaccine, in which full phase 3 studies get over and they met the total case numbers. The complete analysis took place in December, and they are sort of done with the study, but Bharat Biotech still has a long way to go, according to Dr. Kang.
Dr. Kang remarked, No two trials are similar and the comparison would not be efficient, even if the data were final.
Some of the experts still believe that if there are huge differences in the efficacy values that are being reported for such vaccines, it could remarkably show the difference that how efficient the nation is tackling the pandemic COVID-19.
“As we are in pandemic and have access to many vaccines, he thinks that comparison of 80% efficacious vaccine with the 90% efficacious vaccine is not a reasonable one”, mentioned by vaccine expert Dr. Davinder Gill based in Massachusetts. However, he implies that it is fair to compare a 60% efficacious vaccine with one that is 90% efficacious. It shows a huge difference.