A year after it was officially declared that the Covid-19 global health emergency is over, the ghost of the pandemic continues to linger. Except that it isn’t any strain of the virus but fears over the side effects of vaccines that are spooking many. Anglo-Swedish drugmaker AstraZeneca recently withdrew its vaccine, manufactured by the Serum Institute of India, after citing low demand and availability of updated vaccines that target new variants of the virus. This was after the company, which was facing a class action lawsuit in the UK, admitted that the drug could cause extremely rare but life-threatening side effects of blood clotting and low platelet count. The news sparked concerns, including in India where the drug, branded as Covishield, was administered to a majority of the population.
Now, a study by researchers at Banaras Hindu University has said that nearly one-third of surveyed individuals who were administered Covaxin reported long-term adverse events of special interest. Bharat Biotech, the manufacturer of the indigenously developed vaccine, has pointed out lapses and the Indian Council of Medical Research has distanced itself from the study, calling it “poorly designed”.
Given their potential implications to public health, the fears triggered by these episodes are understandable. They also provide grist to the mill of anti-vaxxers and naysayers. A wiser option is to pay heed to the evidence. A 2021 paper in The Lancet — based on a study in April-May that year when the delta variant of the virus ravaged India with lakhs of fresh cases daily — found that Covishield remained effective against moderate-to-severe Covid-19. The risk of the serious side effect that AstraZeneca admitted to — thrombosis with thrombocytopenia or TTS — is as rare as two to three individuals per 100,000 who are vaccinated. A Lancet study also reported an efficacy rate of 77.8% for Covaxin in fighting the coronavirus; during the vaccine’s phase III trial, 12% of over 24,000 participants reported common side effects with 0.5% citing severe side effects. Researchers as well as the World Health Organization (WHO) flagged Covishield’s potential link with TTS soon after it began administering the drug in 2021. But at the same time, estimates suggested that the vaccine saved over six million lives in 2021 alone.
The most important takeaway is that the benefits far outweighed the risks associated with vaccines as the world tried to contain the threat posed by Covid-19. In an interview to The Indian Express, Soumya Swaminathan, former chief scientist at WHO, pointed out that those who have contracted Covid-19 are at a higher risk of suffering health conditions linked to the brain, respiratory, or nervous systems. According to her, “clotting due to Covid is perhaps 100 times more than clotting caused by a vaccine”. Vaccines are a revolutionary contribution of modern medicine that has helped bring down child mortality and prevent lasting disabilities. Their pace of development, too, has grown dramatically. Public anxiety over Covid vaccines persists because of the speed with which they were introduced — barely a year, as opposed to years or even decades. The Covid drugs were a result of factors such as global urgency owing to the scale of the crisis, benefits from past research on tackling infectious diseases, and a drastic pruning of time spent on regulatory approval. All stakeholders, be it researchers or the media, should recognise these realities and not engage in fear-mongering which benefits no one.