Thrombosis with Thrombocytopenia Syndrome: What is TTS, rare side effect of AstraZeneca Covid vaccine?

AstraZeneca admits its Covid vaccine can cause TTS

British pharmaceutical giant AstraZeneca has admitted for the first time that its Covid vaccine can lead to a rare blood clotting condition. The acknowledgement comes in a court filing amidst a class action lawsuit filed by families alleging harm caused by the vaccine.

According to the court documents, Covishield, the Covid vaccine developed by AstraZeneca and Oxford University, can lead to Thrombosis with Thrombocytopenia Syndrome (TTS) in rare cases. Covishield is manufactured by the Serum Institute of India. AstraZeneca has admitted that the vaccine “can, in very rare cases, cause TTS.”

What is Thrombosis with Thrombocytopenia Syndrome (TTS)?

TTS is a rare but serious condition that has been associated with certain COVID-19 vaccines, particularly adenovirus vector vaccines such as the Johnson & Johnson (Janssen) COVID-19 vaccine and the AstraZeneca COVID-19 vaccine.

The condition is characterized by blood clots occurring in unusual locations in the body, coupled with a drop in platelet levels. It gets its name from blood clots (thrombosis) and low platelet count (thrombocytopenia). The condition was earlier referred to as “vaccine-induced immune thrombotic thrombocytopenia” or VITT.

Symptoms typically present four to 42 days after the vaccine is administered. The symptoms can include headaches, abdominal pain, leg swelling, shortness of breath, blurred vision, confusion and more.

According to the Center for Diseases Control (CDC) TTS is classified into 2 tiers based on the location of thrombosis and severity of symptoms.

Tier 1:

In Tier 1 TTS, blood clots occur in uncommon sites like the brain or gut.

Platelet count can drop below 150,000 per microliter.

Positive (+) anti-PF4 ELISA result is supportive, but not required for diagnosis, says CDC.

Tier 1 cases of TTS are considered more serious and carry a higher risk of morbidity and mortality than Tier 2.

Tier 2:

Tier 2 cases affect the rest of the body such as legs or lungs

Positive anti-PF4 ELISA result is required