Though the ICMR had aimed for an August 15 deadline, it is a moot question whether a timeline can be issued when different phases and trials have to be done to ensure safety.
By Dr KK Aggarwal
The Indian Council of Medical Research (ICMR) recently stated that it would like to launch a Covid-19 vaccine by August 15. This drew criticism from all sections of society, including the medical community. Later, ICMR said it had not set any deadline, but the aim was to conduct clinical trials as quickly as possible. Let us evaluate all aspects of the claim.
Covid-19 virus strains are different in various countries. Over 13 strains are in circulation. A virus strain circulating in the US or any other country may not be able to prevent all presentations of the virus in India and vice-versa.
Also, two types of vaccines, one by Oxford and the other by Moderna are using either an adenovirus platform or a messenger RNA platform which may not be able to prevent all known complications and presentations of Covid-19. ICMR and Bharat Biotech are using a live attenuated virus platform and if successful, this will be the best bet as far as the vaccine is concerned as it contains the Indian strains of the virus.
Both Oxford and Moderna are in Phase 3 clinical trials. The 30,000 patient trial of Moderna’s vaccine, expected to start next week, has been delayed. This is a potential hurdle in the company’s ambitious effort to deliver key data by Thanksgiving. Moderna is making changes to the trial plan, called a protocol, which has pushed back the expected start date of the Phase 3 study, according to investigators.
Adar Poonawalla, CEO of the Pune-based Serum Institute of India, on July 7 said the Oxford Covid-19 vaccine is at least six months away from launch. The vaccine is currently in Phase 3 human trials and is being administered to around 8,000 participants. The trial will assess how the vaccine works on a large number of people over the age of 18, and whether it can prevent them from being infected. The Phase 1 trail that began in April is complete and its data will be released shortly. Serum has partnered with British-Swedish drug-maker AstraZeneca to manufacture and supply the vaccine in India and other low and middle income countries.
Most companies are presuming that their vaccine will be successful and are simultaneously taking a calculated financial risk of co-producing the commercial product at the same time to reduce production time.
ICMR is both the interested party and the regulator here and hence, there is not likely to be any red-tapism. This will allow parties to gain at least another 6-7 months due to accelerated government approvals.
A vaccine permission is different from permission for compassionate use of drugs in a pandemic. In such permissions, the drug is used in serious cases with extremely high mortality. A vaccine, on the other hand, is used in healthy people. Safety is of utmost concern.
We know of the Covid-19 virus only for six months now and don’t know if it will persist in our body in an invisible state and erupt later like TB or chicken pox. Similarly, the new vaccine will have to demonstrate that it prevents thrombo-inflammation, immune inflammation and immediate and delayed cytokine crisis at the same time. Equally important is to see that the vaccine does not precipitate a cytokine crisis, thrombo inflammation or immune inflammation in the long term. It would require at least six months to one year of post-vaccine study to find this out.
Remember, it is a live attenuated virus, which means that a live non-replicative virus will be introduced in the body for a possible antibody reaction. Antibodies in the body are of two forms: humoral and cellular. Antibodies produced after the vaccine has been administered are called humoral antibodies. We do not check for cellular immunity, which if not developed or hyper-developed, can cause unwanted situations. Cytokine crisis is a cellular complication.
In the pre-clinical phase of animal studies done so far by the vaccine company and ICMR, adequate antibodies were found. But it is still not known whether these antibodies will be effective, neutralising and long-lasting and can prevent pulmonary and non-pulmonary manifestations of the virus.
Remember this virus has some HIV virus-like properties and we may never be able to make the vaccine. Only time will tell if the vaccine in question will be effective in a single dose or multiple doses like in polio, how long the immunity will last, will a booster dose be required, will it be safe in the elderly, pregnant women and immune-compromised people. Also, will it be an oral or an injectable preparation?
All vaccines have to go through three phases before they can be administered to the community. In each phase, we require a long-term safety profile. In Phase 1 trial, a small group is given the vaccine, while in Phase 3, it is given to a large number of people.
Healthy volunteers are enrolled following the standard guidelines made by ICMR. One cannot force a vaccine on a non-willing or poor person without proper informed consent. In India, for a vaccine to be effective, volunteers need to be from all sections of society and all across the country. A vaccine effective among Dravidians may not work among the Mongolian, Negroid or the Aryan population.
I personally feel that August 15 is an unrealistic date and was intended to expedite the trial and not to launch the vaccine commercially. However, by August 15, the ICMR may be able to demonstrate that this vaccine produces effective antibodies in a person. The safety profile will take more time. Also, if they complete Phase 1 and 2 trials, they will at par with the Oxford and Moderna vaccine and then can compete for Phase 3 trials.
Remember any country which successfully launches the first vaccine will have the first-launch benefit and will become billionaires overnight. Every adversity is an opportunity. As the ICMR is both an interested party and the regulator in this case, we should see its direction in the Covid-19 vaccine trials as a positive one.
In future, every drug, vaccine approval and clinical trial will get the approval from the Drug Controller and ICMR with the same speed and deadline. Hopefully, bureaucracy and red-tapism in the evaluation and approval of vaccine trials will be a thing of the past.
—The writer is President, Confederation of Medical Associations of Asia and Oceania, and Heart Care Foundation of India
Lead Picture: UNI