The messaging on the safety of AstraZeneca’s Covid-19 vaccine needs to get a lot more clear if nations that have approved it for use—India is using it, licensed to SII as Covishield—are to effectively battle vaccine-hesitancy.
One of its top officials had even said that the incidents reported till then were not in a greater number or frequency than that reported for the general population.
The messaging on the safety of AstraZeneca’s Covid-19 vaccine needs to get a lot more clear if nations that have approved it for use—India is using it, licensed to SII as Covishield—are to effectively battle vaccine-hesitancy. Vaccine-hesitancy has emerged as a potent threat, against the backdrop of Covid-19 vaccine development being, understandably, rushed and turnaround times for regulatory approval being significantly shorter than usual.
But, the guidance from the European Medicines Agency (EMA) seems to clear very few doubts surrounding the vaccine. Reports of coagulatory disorders—blood clots and low platelet levels that could cause haemorrhage—in a few recipients had prompted many countries, chiefly in Europe, to suspend the deployment of the vaccine for a few days last month. At the time, the EMA had said that it had no evidence linking the vaccine to the disorders, and that the matter was being reviewed by its experts. One of its top officials had even said that the incidents reported till then were not in a greater number or frequency than that reported for the general population.
On April 7, the EMA stated that there was “a possible link” between the vaccine and the disorders, but maintained that the overall benefit-risk ratio remains overwhelmingly in favour of benefit. The EMA’s safety committee looked at all available evidence, and considered advice from “an ad hoc expert group” before making its view public. Yet, the EMA’s statement doesn’t do much to allay fears, in terms of what cohort of vaccine-recipients could be at risk. Studying 86 such coagulatory disorder cases—from a pool of 25 million who received the shot in the European Economic Area and the UK—with 18 fatalities, the EMA concluded that the disorders were a “very rare side-effect” of the vaccine. Bear in mind, the absolute numbers have grown since the EMA’s review, reaching 222 among 34 million vaccinated. While it spoke of a “plausible” cause—an immune response, leading to a condition similar to one seen sometimes in patients treated with heparin, an anticoagulant—it stated that there was not enough evidence to identify the risk factors. It, though, did well to put out a list of symptoms that vaccine-recipients need to watch for and seek immediate medical assistance if they experienced any of these. It did point out that most cases reported were in women under 60 years and had occurred within two weeks of the person receiving the first dose.
Absent comprehensive risk guidance, countries have chosen disparate approaches—while Italy has restricted the vaccine to only those aged 60 and above, the UK ha advised its 18-29-year-olds to opt for other vaccines. Such mixed messages from governments is likely to stir further apprehensions among the public, not just in Europe but in other jurisdictions where the vaccine is being given to people. The core messaging needs to focus on the extremely small number of people affected in the total pool of those vaccinated while the experts work on identifying a larger set of risk factors, assuming ‘women under 60’ is a risk-label. Else, if trust in the vaccine dips significantly, global vaccination efforts will take a big hit since it is the second most-commonly-used Covid-19 vaccine globally.