New Delhi:
Thrombosis Thrombocytopenia syndrome (TTS) – a blood clot disorder – is a rare side effect of AstraZeneca's Covid vaccine, and the risks far outweigh the jab's benefits, doctors said today.
This comes after reports said AstraZeneca has accepted for the first time in court documents that its vaccine, developed with the University of Oxford, may increase the risk of a rare and serious blood clot.
The Oxford-AstraZeneca Covid vaccine, sold as Covishield in India and Vaxzevria in Europe, is a viral vector vaccine developed using the modified chimpanzee adenovirus ChAdOx1.
Covishield, manufactured and marketed in India in collaboration with the Serum Institute of India (SII), was widely administered in the country – to almost 90 percent of India's population.
“Thrombotic thrombocytopenic syndrome (TTS) is one of the rare but very serious side effects that have occurred as part of vaccine-induced immune thrombotic thrombocytopenic purpura (VITTP). The incidence was only one in 50,000 (0.002 percent), but in a huge population the number becomes significant,” infectious disease expert Dr. Ishwar Gilada to IANS.
“TTS is a very rare condition that results from an abnormal immune response. Although it has several causes, it has also been linked to adenovirus vector vaccines and the WHO published a report on it on May 27, 2021,” says Dr. Rajeev Jayadevan, co-chairman of the Indian Medical Association's National Covid-19 Task Force, told news agency IANS.
What is the case? The British-Swedish multinational pharmaceutical company has admitted for the first time in British court papers that its Covid vaccine may cause a rare risk of blood clots, the Telegraph reported.
Some 51 cases have been brought against the pharmaceutical giant in the UK High Court over claims that its Covid vaccine caused death and serious injury.
The victims and grieving relatives have demanded damages estimated at up to £100 million, the report said.
Although AstraZeneca disputes the claims, “it accepted in a legal document submitted to the Supreme Court in February that its Covid vaccine 'may cause TTS in very rare cases',” the report said.
TTS causes people to have blood clots and low platelet counts.
AstraZeneca's Covid vaccine and link to TTS? In India, almost 90 percent of people who received the Covid vaccine received the AstraZeneca vaccine called Covishield in India. It is made from a harmless cold virus, which comes from chimpanzees, and is called adenovirus.
“Once this virus is genetically modified or engineered to match SARS-CoV-2, an organism that causes Covid-19, it acts on a spike protein. So the vaccine is incorporated with the genetic sequence of the S-spike protein,” said Dr Ishwar, Secretary General, Public Health Organization India, Mumbai.
He explained the mechanism of the potential TTS risk and said that the vaccine is injected into the arm, which is located in the deltoid muscle. However, sometimes it also enters the bloodstream, instead of just ending up in the muscles. Once it enters the bloodstream, the adenovirus in the vaccines acts like a magnet, with a special affinity for a type of protein in the blood called platelet factor 4 (PF4),” the doctor said.
“Although PF4 is normally used by the body to promote blood clotting, on rare occasions the body's immune system mistakes it as a foreign body or invader and then releases antibodies to attack it – this becomes a mistaken identity named.
“It is theorized that such antibodies then react and clump with PF4, forming the blood clots that have become so strongly associated with the vaccine. Such clots in the brain and heart can cause disastrous side effects,” the doctor said.
Should all Covishield vaccine users be concerned?
“No, there is no need, because it has happened to very few people,” said Dr. Ishwar.
“The difficulty is to distinguish between the complications caused by Covid itself or by long Covid or the vaccine. That remains debatable and indistinguishable before the scientific community and also the legal fraternity,” he added.
Importantly, Dr Rajeev said: “People who have been vaccinated generally have a lower risk of death from Covid and complications such as post-Covid heart attacks and strokes afterwards.”
“While there are extremely rare serious side effects for vaccines, the benefits far outweigh the risks. Covid vaccines have prevented hundreds of thousands of people from dying. For example, in the US, 232,000 to 318,000 people have died from Covid, due to vaccine refusal due to disproportionate fear of vaccination,” he added.
(Except for the headline, this story has not been edited by Our staff and is published from a syndicated feed.)