Safety issues regarding covishield may heighten vaccine hesitancy

While covid-19 vaccine uptake in India is already low, safety issues surrounding Oxford-AstraZeneca vaccine may further heighten hesitancy among beneficiaries. After European and UK regulators talked about a possible link between the Oxford-AstraZeneca vaccine and some rare occurrences of blood clots, Indian panel on adverse effects following immunization (AEFI) is studying safety of the vaccine available in India under brand name covishield being manufactured by Serum Institute of India (SII). Covishield accounts for 90% of the doses administered in India so far while rest is covaxin by Bharat Biotech.

However, in India there have been no reports of blood clotting disorders, some beneficiaries, especially healthcare workers are wanting to get covaxin. “Earlier people were inclined towards covishield in comparison to covaxin. But after the interim data on effectiveness of covaxin came which claimed the vaccine is 82% effective in preventing covid-19, people started preferring covaxin,” said Dr Dinesh Kapil, senior consultant pediatrics, Red Cross Hospital who recently completed his two doses of covaxin.

India however doesn’t not allow choice or intermixing of covid-19 vaccines but people like Girish Chandra Bharti want to wait. “With so many reports regarding safety of the covishield vaccine, I would want to wait for some more options as the government has said it will soon launch more vaccines,” said Bharti. In a significant development, the European Medicines Agency (EMA) on Wednesday had said that its vaccine safety committee concluded that the unusual blood clots caused by the AstraZeneca vaccine should be considered as a “very rare" side effect. In the UK, the Joint Committee on Vaccination and Immunisation advised that people below 30 years of age with no other condition should be offered an alternative to the AstraZeneca vaccine.

Public health experts coming in support of the vaccination with both vaccines said that the benefits are way more than then risks. “Globally 24 million doses of the AstraZeneca vaccine is given, from that only 84 cases of blood clots were found. That accounts to 0.035% of the total doses, which is a very small number. My argument is that even if we don’t take the vaccine, the potential for blood clots will always be there,” said Dr Vasant Nagvekar, Consultant - Infectious Diseases at Global Hospitals - Mumbai.

“Even if there was no Covaxin, hospitals still get patients who suffer from blood clots. As the number of people getting vaccinated in India is Huge, and they are all from the high age group, these kinds of problems are bound to arise. The benefits of the vaccine are much more than the risks,” he said.

According to reports the UK’s Medicines and Healthcare products Regulatory Agency (MHRA) has reviewed 79 cases of clot after administering 20 million doses. AstraZeneca vaccine EMA has reviewed 86 cases of blood clot resulting from about 25 million Europeans who received the AstraZeneca vaccine.

Similarly, the UK’s MHRA has identified 30 cases after the use this vaccine. Public health experts in India have said that government should come out the data as soon as possible. “Though EMA and MHRA have issued advisories regarding plausible cause and effect association between the vaccine and the clots, more investigations would be needed to nail it. Together 40-45 million doses have had 165 cases. India has used close to 85-86 million doses of Covishield,” said Lalit Kant, a scientist and former head of epidemiology and communicable diseases at the Indian Council of Medical Research (ICMR).

“Even after using more than twice the number of doses, India has not reported any case of clot after receiving Covishield vaccine. Is it that the genetic make of Indian Indians protects them from clots and there are actually nil cases, or the AEFI system is weak and has not been able to pick up the cases, or the scientists who do the causation analysis have failed to find a link however remote,” said Kant.

Kant further argued, there has also not been any authoritative statement from the regulators or the Government on this issue, except for saying that the vaccine is safe. “This adds to the uneasiness of the people who have to receive the second dose or are eligible for vaccination. The authorities should clear the air at the earliest. This news of clots is fodder to the vaccine hesitancy group, as it is we were have a problem of people not accepting the vaccination, it would further complicate the situation,” said Kant.

SII has maintained that the vaccine is safe and effective and people should go ahead for vaccination.