Former Union health minister Harsh Vardhan holds up a vial of Covaxin, at AIIMS Delhi, January 16, 2021. Photo: Reuters/Adnan Abidi/File Photo
- AIPSN president Sabyasachi Chatterjee expressed multiple reasons to doubt the data underpinning the homegrown Covaxin COVID-19 vaccine.
- His first, and newest, cause for concern is the WHO’s delay in granting Covaxin its stamp of approval – required for the vaccine to gain acceptance around the world.
- His other concerns include weak early data from the phase 3 trial and the trial paper’s failure to explain deaths of a few participants during the trial.
Sabyasachi Chatterjee, the president of the All India People’s Science Network, says the WHO’s continuing delay in granting emergency use authorisation (EUA) to Covaxin is a sign the WHO has problems doing so.
Although on September 30 Balram Bhargava, the head of the Indian Council of Medical Research, said at a press conference that all Covaxin data had been given to the WHO, on the same day The Wire received a text message from a senior official of the WHO explaining the delay, saying: “There are many queries and a bit more back and forth than was expected.” This suggests the WHO needs more details and also that its experts have concerns with Covaxin’s data.
To him, the WHO’s delay also revives familiar questions about India’s Drugs Controller General’s approval for Covaxin well before its third-phase trial results were available.
Chatterjee said another indication about potential issues with Covaxin’s phase-3 trial data emerges when comparing Covaxin’s fortunes with those of vaccines made by Pfizer, Moderna and AstraZeneca.
Six weeks after Pfizer published its phase 3 trial results, the WHO granted its EUA. With Moderna and AstraZeneca, that happened roughly nine weeks after they published their results. But with Covaxin, 12 weeks have lapsed since its maker, Bharat Biotech, released its phase 3 results. Chatterjee said, “This suggests that this delay is because of something inadequate.”
Chatterjee emphasised that he was relying entirely on what Bharat Biotech had published in a preprint paper on July 2. It’s possible – if unlikely – that Bharat Biotech had made more and better data available to the WHO and which has thus far not been released to the public. However, Chatterjee added, given “the scientific community finds (the data) extremely inadequate,” he finds this possibility hard to believe.
He first expressed concerns about how the preprint paper handled deaths and adverse effects during the phase 3 trials. He said 15 deaths have been acknowledged but its authors, the trial researchers, haven’t explained what could have caused them, beyond a general statement that they are not a result of the vaccination.
Chatterjee also said the paper accepts there were 39 people in the vaccinated group and 60 in the unvaccinated group, but doesn’t differentiate between minor, moderate and serious adverse effects.
He reserved his greatest concern for the efficacy number for the above-60 age group, which is the section of the population most vulnerable to severe disease. The paper lists this as 67.8% but its 95% confidence interval (CI) – a measure of the finding’s reliability – range from 8% to 90%. This is a very wide range, indicating that the ‘67.8%’ measure is quite unreliable.
Chatterjee said that there are two further Covaxin phase 3 efficacy datapoints for which the 95% CIs are worryingly wide: the 65.2% efficacy against the delta variant, CI: 33.1% to 83%; and the 93.4% efficacy against severe COVID-19, CI: 57.1% to 99.8%.
He also told The Wire that he was surprised that even three months after Covaxin’s phase 3 trial results were announced, they have not been published in a journal. To him, this is a sign that journals have questions as well. Chatterjee said this point is underlined by the fact that six months ago, on March 8, The Lancet published Covaxin’s phase 2 interim results. So one would have expected the journal to publish the phase 3 results as well, but so far that has not happened.
Finally, Chatterjee called Covaxin’s delay in securing the WHO’s EUA “a serious setback to Indian science”. He also cautioned that Covaxin’s problems could affect how other homegrown vaccines, such as Zydus Cadila’s ZyCoV-D, are perceived.