With the Pfizer-BioNTech receiving regulatory approval, Moderna vaccine handing in its request, and the Oxford-Astra Zeneca vaccine lining up to be the next, several Covid-19 vaccines are now beginning to enter the real world after the clinical trials on volunteers. With this come cheers, concerns, and controversies.
The cheers are well-deserved for the spectacular success of science in developing and testing the new vaccines for a novel virus within eleven months after its reported appearance. While this would be true even for the conventional platforms for developing anti-viral vaccines, the super-fast success claimed for the entirely new mRNA platform has been a dazzling display of scientific prowess.
Concerns Around mRNA Vaccine for COVID-19
The concerns are many.
Have the trials been rushed, the regulators pressured and clearances prematurely given without adequate period of observation and on the basis of incomplete evidence?
Why have the data not been placed for peer reviewed publication in scientific journals?
Why are the data not in the wider public domain?
Is science by press release the right way of building belief in the efficacy and safety of vaccines?
Is the period of observation too short for assessing safety, especially to study longer term adverse effects?
Even if efficacy has been assessed adequately and found to be reassuring, should the trials continue longer till the safety issues are studied more thoroughly?
Will continuing recruitment into the study give us valuable information on possible differences in age and gender groups, with sufficient numbers for subgroup analyses?
Will it even be ethical to continue the trials with a placebo arm, if the vaccine has been found to be effective in the active arm of the trial?
Why US and Britain Are Exchanging Barbs Over Pfizer and Moderna Vaccines
The two mRNA vaccines have raced to submission for approvals ahead of others who have undertaken phase 3 trials. The Pfizer-Biontech vaccine has already been given an expedited emergency use authorisation by the British regulators. They had access to rolling data even when the trial was on.
The American regulators are taking more time. They do not appraise piecemeal data while the study is still on. Also, they require at least two months of follow up on the study subjects to assess safety. There has been an exchange of trans-Atlantic jibes as to whether this regulatory comparison proves that British science is superior to American or European science as claimed by a British minister.
It is indeed a surprise to see the staid and steady English beat the Americans to the quick draw. Were they shooting from the hip in a hurry? Will the rest of the world applaud the speed or worry about the safety?
The two mRNA vaccines may be the first to win regulatory approvals but their safety issues are not fully settled.
Further, the logistic cold chain challenges of severe sub-zero temperatures for their storage and transport place them beyond the logistic capabilities of most national health systems. It will be a challenge that will prevent even India from considering their use for large scale immunisation across this vast country. Their production volumes in 2021 too will not be high enough in to meet global demand.
What About Russia and China?
Running on different tracks, following rules of their own, are the Russian and Chinese made vaccines, which use conventional vaccine development platforms. Emergency use authorisations were issued even before the phase 3 trials commenced and some population groups are being immunised even as the trials are proceeding.
Apart from confident assertions of efficacy and safety by their manufacturers, we have yet to see large scale data in the public domain, for rigorous scientific scrutiny. We await that day, as the uncertainty needs to be resolved before global uptake.
There are other vaccines which are also likely to lay claim for efficacy, safety, easier cold chain requirements and capacity for high volumes of production for global use.
Is Oxford-Astra Zeneca India’s Best ‘Shot’?
The Oxford-Astra Zeneca vaccine, producing the spike protein on a chimpanzee adenovirus platform, has also claimed high rates of efficacy and safety although the inadvertent use of two different dosing schedules produced a surprise, with the unintended regimen showing greater efficacy. It is also likely to have a higher production volume in 2021 than both the mRNA vaccines.
Besides the licensed production of the Oxford vaccine, India is also undertaking the evaluation and production of other vaccines: Bharat Biotech- ICMR; Zydus-Cadila; Biological E-Baylor; and a Russian vaccine.
We await their trial results. If one or more of them pass the Indian regulatory test, we should have high levels of domestic production to keep our supply chain in good flow. They are likely to be less expensive and far more easy to handle than the mRNA vaccines. Though, they may not be as spectacular from the viewpoint of scientific advance.
The high income countries can vie for the mRNA vaccines, leaving the space open for accessing less expensive and easier to manoeuvre vaccines to us and other less affluent countries.
Never mind if someone across the road gets the fancy Lamborghini. We can do well with the India made models better suited for our road conditions.
(The author, a cardiologist and epidemiologist, is President, PHFI. He is the author Make Health in India: Reaching a Billion Plus. This is an opinion piece and the views expressed are the author’s own. The Quint neither endorses nor is responsible for them.)