Vaccines hold the key to controlling pandemic

THE new year has begun on a positive note with two vaccines against Covid-19 getting emergency use approval from the Subject Expert Committee of the Drugs Controller General of India (DCGI). Covishield (Oxford University-AstraZeneca) is being manufactured by the Pune-based Serum Institute of India (SII), while Covaxin is being made by Hyderabad-based Bharat Biotech. India reached the tally of one crore Covid-19 cases and 1.5 lakh deaths earlier this month, while the total cases across the world have crossed 9 crore in the past 12 months since the pandemic began.

Since there are few effective drugs against the novel coronavirus, the world had been waiting for a vaccine to prevent the disease caused by the virus. A massive multi-national effort was launched soon after the detection of the viral genome in January 2020 with the cooperation of WHO, Coalition for Epidemic Preparedness Innovations (CEPI), Gavi Alliance, Accelerating Covid-19 Therapeutic Interventions and Vaccines (ACTIV) and Bill and Melinda Gates Foundation. By the beginning of December, developers of several vaccines had announced excellent results of large trials. On December 2, a vaccine made by Pfizer with German firm BioNTech became the first to be approved for emergency use against Covid-19. The fastest any previous vaccine had been developed was in four years — for mumps in the 1960s. The world has been able to develop Covid-19 vaccines so quickly because of previous experience, enormous funding, carrying out different stages of development in parallel, and the urgency prompting early regulatory authorisation.

Currently, there are 172 candidate vaccines under development and another 62 have reached the stage of clinical development with 18 in phase III trials. Phase I trials cover safety while phase II trials look at safety and immunogenicity, i.e. production of neutralising antibodies and T-cell response. Phase III trials must include thousands of subjects with follow up as well before regulatory approval is granted. Emergency use approval is granted on the basis of safety data and confirmation of optimum immunogenicity, at times even in the absence of phase III trial data.

It is a matter of pride for India that these two vaccines are being made in the country. It is a big step towards the goal of Atmanirbhar Bharat. Significantly there are other vaccines in different stages of development in India by Zydus Cadila, Dr Reddy’s Laboratories, Biological E and Bharat Biotech (two vaccines) among others. The government has already started buying and transporting the SII vaccine across the country. The government has ordered 1.1 crore doses of Covishield and 55 lakh doses of Covaxin and plans to buy a total of 5.6 crore doses of Covishield by April. We should also be supplying vaccines to many countries soon, like the way India had exported hydroxychloroquin to 88 countries last year.

Covishield, being made in collaboration with Oxford-AstraZeneca, has an efficacy rate of 70% and 90% depending upon half or full dose of the first shot, respectively, in a phase III trial. This exceeds the threshold of at least 50% efficacy set by regulatory agencies including WHO, DCGI and FDA. It was first approved for use in the UK recently. Bharat Biotech vaccine Covaxin, developed together with the ICMR and the National Institute of Virology, has been given emergency approval on the basis of its safety and immunogenicity data. Its phase III trial on over 25,000 subjects is in progress. There were some questions raised about the approval to Covaxin, but DCGI VG Somani has allayed these fears, saying that both approved vaccines are ‘110 per cent’ safe. Minor side effects like local pain and fever are expected and should not be troublesome. Makers of both vaccines will, however, have to submit safety and efficacy data of the ongoing trials periodically.

It must be recognised that all clinical trials, including those on vaccines, have to be registered before their initiation and periodic updates have to be provided. This is to ensure transparency and an ethical obligation to participants and the research community. Based on the principles of the Declaration of Helsinki and good clinical practice (GCP) guidelines, clinical trials are overseen by a number of committees, like the Trial Steering Committee (TSC) and the Data Monitoring Committee/Data Safety Monitoring Board (DMC/DSMB). In addition to trial oversight committees, the trials are centrally monitored too. Every serious adverse event is reported to the ethics committee and the DMC/DSMB looks into it. Trials on Indian vaccines are also being conducted under similar monitoring. Bharat Biotech has a track record of clinical trials in 20 countries and has given the world two innovative vaccines, one against rotavirus and the other against typhoid.

To dispel doubts arising from a report each about major adverse events in recipients of Covishield and Covaxin, the Indian Medical Association (IMA) has asked its 3.5 lakh members to voluntarily get vaccinated first. In a recent statement, the IMA said that it stood with “the scientists to endorse the safety and efficacy of both vaccines cleared by India”.

Though vaccination has taken off in 50 countries since December 2020, only 2.5 crore people have received the vaccine. There have been problems in transportation and distribution, apart from vaccine hesitancy among many people. Vaccine hesitancy is common — 29 per cent of healthcare workers in US and 40 per cent in the UK said they were reluctant to get vaccinated. Various rumours have been floating on social media even before any vaccine was approved. In some countries, Chinese vaccine Sinovac was linked to a porcine component and termed haram. The Indonesian government had to get their religious leaders to announce that the vaccine is acceptable. Many other Muslim nations have also endorsed the vaccines. The Pope has reassured the Catholics that Covid vaccines are safe and do not infringe upon their religious beliefs.

Beginning today, the rollout of Covishield and Covaxin is a major leap forward in our fight against Covid-19. The use of these vaccines is safe and will be an important step in controlling the pandemic.