AstraZeneca's Covid vaccine may cause blood clotting: Should you be worried?
AstraZeneca’s Covid vaccine may cause blood clotting: Should you be worried?
The British pharmaceutical company, AstraZeneca, has for the first time admitted in court documents that its vaccine against Covid-19 has the potential to cause TTS, a rare side effect associated with blood clotting.
TTS or Thrombosis with Thrombocytopenia Syndrome causes blood clots and leads to low blood platelet count.
The company is facing up to 51 litigations, being sued in class action over claims its vaccine caused death and serious injury in dozens of cases.Â
This news has affected millions worldwide, including people in India, where the vaccine, under the brand name of Covishield, was administered to reduce severe Covid-19 complications.
SHOULD YOU BE WORRIED?
India Today spoke about AstraZeneca’s admission about the rare side effect triggered by its Covid-19 vaccine.
“The adverse effects related to vaccine usually occur within a few weeks (1-6 weeks) after the administration. Hence, people in India who took the vaccine 2 years ago need not worry,” said Dr Sudhir Kumar, Neurologist, Apollo Hospital, Hyderabad.
Dr Rajeev Jayadevan, Co-Chairman of the National Indian Medical Association, added that this particular outcome is reported only in the first month following the first dose, not afterwards.Â
In India, Dr Kumar said that the incidence of TTS after the vaccine is not known.Â
“Only isolated case reports have been reported. So, TTP is extremely rare after Covid vaccination, considering millions of vaccine doses have been administered,” the expert said.
More than 17 million people have received the vaccine in the United Kingdom and the European Union to date, with fewer than 40 cases of blood clots reported as of last week.
These revelations are not new, the expert said. In fact, isolated case reports of TTS from various parts of the world after Covid-19 vaccinations have been published since 2021.Â
“TTS is a well-known and recognised disease for the past 100 years, as the first case was reported by Eli Moschcowitz in a 16-year-old girl in 1924. The underlying mechanisms of TTP have been known since 1982, and has been part of medical curricula during the past 4 decades,” said Dr Kumar .
While Covid vaccines do increase the risk of blood clots, the risk is very small.Â
Dr Kumar said, “This has been proved in many scientific studies published from India and other countries. Just for record, Covid infection increases the risk of blood clot formation, much more significantly than that of covid vaccines.”
Dr Jayadevan added that Covid-19 by itself is an established cause of clots, heart attacks and strokes occurring afterwards, and those who are vaccinated are at lower risk for these outcomes.Â
IS COVAXIN BETTER THAN COVISHIELD?
Dr Kumar said that there’s not enough data to help us choose one Covid vaccine over another, based on the risk of adverse effects.
“Moreover, TTS has been reported with other vaccines as well, such as influenza vaccine, pneumococcal vaccine, H1N1 vaccination, and rabies vaccine,” said Dr Kumar.Â
Dr Jayadevan added that both vaccines are effective.
“There is nothing to say one is better than the other. All vaccines and medical treatments have side effects. Crores of people who took these vaccines in India are alive and well now,” he said.Â
WHAT ARE THE SIDE EFFECTS?Â
Rare side effects associated with adenovirus vaccines like AstraZeneca and Johnson’s Jansen could include Guillain Barre syndrome (which causes paralysis of arms and legs), Bells’ palsy (causes weakness of face), stroke, cerebral venous sinus thrombosis, and heart attacks.
AstraZeneca vaccine was stopped in various countries following the rare side effect of blood clotting.Â