AstraZeneca recalls Covid vax: Risk benefit currently against further use, say experts

New Delhi, May 8: The risk benefit of AstraZeneca's Covid-19 vaccine is currently against further use, said experts on Wednesday amid a report of a global recall of the jab by the British Swedish pharma giant.

The recall of its Covid-19 vaccine, made in collaboration with Oxford University, worldwide, comes after the drugmaker in February admitted in the UK court about its potential side effect, Thrombotic Thrombocytopenic Syndrome (TTS), a rare blood clot disorder.

The Telegraph reported AstraZeneca voluntarily withdrew "marketing authorisation" of its Covid vaccine, sold as Covishield in India and Vaxzevria in Europe.

While it can now no longer be used in the European Union, the company said it will initiate withdrawals from the global market.

"It is no longer a useful vaccine. The virus has changed. The risk benefit currently is against further use," Anurag Agrawal, Dean, Trivedi School of Biosciences, at Ashoka University.

"In India, with severe Covid becoming less common presently, possibly due to a combination of hybrid and herd immunity, a decision to vaccinate with the AstraZeneca vaccine should be made after discussing the likely risks and benefits. This is especially true for younger and low-risk individuals," added Lancelot Pinto, Consultant Pulmonologist and Epidemiologist, P. D. Hinduja Hospital and MRC, Mumbai.

The company, credited for saving more than six million lives during the recent Covid-19 pandemic, "accepted, in a legal document submitted to the High Court in February, that its Covid vaccine 'can, in very rare cases, cause TTS'," the report said.

TTS is a rare side effect that can cause people to have blood clots and a low blood platelet count and has been linked to at least 81 deaths in the UK as well as hundreds of serious injuries.

Lancelot told that TTS occurs "possibly due to the adenovirus vector".

"A systematic review including studies conducted till August 2021 found 167 reported cases worldwide. The incidence is believed to be 2 per 100,000 people vaccinated with AstraZeneca aged 60 years or older, 2-3 per 100,000 people vaccinated with AstraZeneca aged under 60 years" he added.

Importantly, the doctor noted that "the side effects typically appear within 6 weeks post vaccination, and are more common after the first dose".

As per modelling estimates, Covid vaccination saved between 14.4-19.8 million deaths in the first year, reducing deaths by 63 percent.

Meanwhile, AstraZeneca in a statement said that the vaccine recall is due to "commercial reasons". It said that with multiple Covid variants and related vaccines, "there is a surplus of available updated vaccines".