Published: 04th July 2020
Scientists strike note of caution as 'Made in India' vaccine programme gains momentum
Immunogenicity is the ability of a foreign substance, such as an antigen, to provoke an immune response in the body of a human or other animal, explained the experts
India's COVID-19 vaccine programme has gained sudden traction but it is imperative to strike a balance between giving it high priority and rushing into a process that takes months, even years, several scientists said on Saturday, a day after the ICMR announced it envisaged a preventive by next month.
There was hope but caution too as the Indian Council of Medical Research on Friday said it aims to launch the world's first COVID-19 vaccine by August 15. The same day, Ahmedabad-based Zydus Cadila announced it has got the Drugs Controller General of India's (DCGI) nod for human clinical "trials for a potential vaccine.
"Fast tracking a vaccine trial in four weeks for safety, immunogenicity and efficacy is just not possible if things are to be done correctly," Shahid Jameel, virologist and CEO of the Wellcome Trust/DBT India Alliance, a public charity that invests in building biomedical sciences and health research framework, told the media.
Immunogenicity is the ability of a foreign substance, such as an antigen, to provoke an immune response in the body of a human or other animal, he explained. Virologist Upasana Ray added that an accelerated launch or promise for launch of a vaccine against the novel coronavirus deserves applause but it is important to ask whether 'we are rushing too much'.
"We must rush albeit carefully. Giving this project high priority is absolutely important. However, excess pressure might not necessarily lead to a positive product for public use," the senior scientist at CSIR-IICB, Kolkata said.
India's premier medical body ICMR has said 12 clinical trial sites for the indigenous Covaxin, being developed in collaboration with the Hyderabad-based Bharat Biotech and the National Institute of Virology (NIV), have been identified.
It asked medical institutions and principal investigators to ensure that the subject enrolment is initiated no later than July 7. "It is envisaged to launch the vaccine for public health use latest by August 15 after completion of all clinical trials," ICMR Director General Balram Bhargava said in his letter to the principal investigators of the 12 sites. The tone of the letter and the haste it indicated had some scientists worried.
They questioned the timeline of the announcement mentioned in the letter, and advised against subverting the due vaccine development process. "The ICMR 'letter' is, to say the least, a deeply inappropriate letter, in tone and content, both in terms of the integrity of due processes of product development, and in terms of technically realistic estimates," immunologist Satyajit Rath said.
Vaccine development is a multi-phase process. Phase 1 trials are small-scale, usually involving few participants, to assess whether the vaccine is safe for humans. Phase 2 trials often involve several hundred subjects, and mainly evaluate the efficacy. The final phase involves thousands of people to further assess the efficacy of the vaccine over a defined period of time, and can last several months.
Ray added that a vaccine normally takes at least 12-18 months to pass all necessary clinical trial phases. "From now till August 15, the company has just over a months' time to wrap up everything that normally a vaccine development process requires for releasing a vaccine for clinical use," she said.
"How can such a sharp timeline be even decided? Where does the evidence come from that by such a short time all the essential steps will be completed? What about the safety and efficacy, the fundamental steps of any drug development? Have even the pre-clinical studies been completed? Too much rush comes with possible risks," she said.
Ray noted that there are some broad mandatory steps for developing a vaccine. Preclinical tests in small animals and mammals, she stressed, are essential to assess neutralising antibody titers and that itself can take at least a month or two. A titer is a laboratory test that measures the presence and amount of antibodies in blood. "Next, we check for safety. Then is the human trial. Even if we are in a deep rush we have to wait for some time for immunised individuals to start generating antibodies. After that a population needs to be monitored over time to investigate if people are still being infected," she explained.
Skipping steps could either be dangerous or lead to poor product, Ray said. "We must not compromise with the standard, the quality. We don't need to be the first to launch a drug but what we need is a Made in India vaccine that the entire world can rely on," she added.
The vaccine landscape in India has been also bolstered after the approval for Zydus Cadila's vaccine candidate. It was fast-tracked following a recommendation by the subject expert committee on COVID-19, considering the emergency and unmet medical need during the pandemic.
"DCGI Dr V G Somani has given approval for the phase I and II clinical trials (on humans) of the potential novel coronavirus vaccine developed by Zydus Cadila Healthcare Ltd on Thursday after its animal studies were found to be successful," an official source said.
Jameel, winner of the 2000 Shanti Swarup Bhatnagar Prize for Science and Technology, one of the highest Indian science awards, noted that it is a vaccine funded by Biotechnology Industry Research Assistance Council (BIRAC) and the Department of Biotechnology.
"Congratulations to Cadilla, BIRAC and DBT. We would look forward to properly conducted trials and good news in due course," he said.
"I am glad that a locally made vaccine candidate is making the same progress that others elsewhere in the world are making, not just with SARS-CoV-2 vaccine candidates but with DNA-based SARS-CoV-2 vaccine candidates, and I will look forward to the results," added Rath from Delhi's National Institute of Immunology (NII).
Gautam I Menon, a professor from the Departments of Physics and Biology at Ashoka University, said Zydus Cadila's vaccine appears to have shown safety and efficacy in animal trials and so they have been allowed to go to the next step, to human trials. "This is the standard procedure. It is the human trials that are time-consuming and it is important to get this right," Menon added.
In another development, Serum Institute of India (SII) CEO Adar Poonawalla told The Tribune newspaper that the Covid-19 vaccine being developed at the University of Oxford will hit the market by the year-end. ChAdOx1 nCoV-19 is made from a virus (ChAdOx1), which is a weakened version of a common cold virus (adenovirus) that causes infections in chimpanzees, and has been genetically changed so that it is impossible for it to reproduce in humans. "I think it is likely that the ChAdOx1-S vaccine candidate which has entered a phase 3 clinical trial in Brazil, will give at least somewhat promising results by late this calendar year," Rath said.
"Whether this will lead to the 'vaccine' becoming available in the market, and in the public health system, more importantly, by the end of this calendar year in India is much more uncertain, Mr Poonawala's welcome optimism notwithstanding," he added.