In 2015, the World Health Organisation’s Strategic Advisory Group of Experts on Immunisation characterised vaccine hesitancy as a “delay in acceptance or refusal of vaccination despite availability of vaccination services”.

Four years later, but before the coronavirus epidemic swept the world, WHO identified vaccine hesitancy as one of the top ten global health threats. But in 2020, with Covid-19 having emerged as a global scourge and with accelerated vaccine development programmes having brought the world within nodding distance of an antidote to the virus, concerns about the efficacy of vaccines are bound to dominate public discourse in the weeks and months ahead.

This discourse was energised at the weekend with allegations that a 40year-old participant from Chennai in a third phase clinical trial of one of the vaccine front-runners suffered a virtual neurological breakdown and impairment of cognitive functions 10 days after administration.

In the crosshairs of the legal action initiated by the man’s family is the AstraZeneca vaccine candidate manufactured by the Pune-based Serum Institute of India. The family has sought compensation of Rs 5 crore, but beyond the money involved, the complaint has cast a fearful shadow over the vaccine’s side-effects.

While the Drugs Controller of India has announced an investigation into the complaint, the response of Serum Institute of India must raise some eyebrows. The manufacturer has dismissed the charges as “malicious and misconceived” and threatened to seek damages of more than Rs 100 crore from the afflicted person, a business consultant.

While claiming sympathy with the complainant’s medical condition, it has said there is “absolutely no correlation” with the vaccine. It said, “The claim is malicious because the volunteer was specifically informed by the medical team that the complications he suffered were independent of the vaccine trial he underwent.”

This is in contrast to AstraZeneca’s response to a report of a woman volunteer in the United Kingdom reporting neurological distress in September, and another volunteer reporting a neurological problem in July. On both earlier occasions, clinical trials were halted. Later, it was claimed that one volunteer suffered from multiple sclerosis, and the other had a spinal inflammatory disorder called transverse myelitis.

But in the Indian case, the vaccine manufacturer has straightaway chosen to go on the offensive, threatening the complainant with a countersuit and hefty damages. This seems both unfortunate and insensitive. For there is no dispute on two critical facts. One, the man did participate in the AstraZeneca vaccine trial. And two, he did a few days later apparently suffer considerable neurological damage.

Whether or not the two events are related is for an investigation to determine, and that cannot be preempted by waving a club at a person in obvious distress. On the contrary, the vaccine manufacturer must join the investigation and allay fears that people have. Certainly, the report from Chennai has caused huge consternation and will likely add to the vaccine hesitancy many already feel.