Risks associated with thrombosis with thrombocytopenia syndrome (TTS)

Source: The post risks associated with thrombosis with thrombocytopenia syndrome (TTS) has been created, based on the article “Side effects of AstraZeneca vaccine: Medicine is clear now to the courts” published in “Indian Express” on 4th May 2024.

UPSC Syllabus Topic: GS Paper 2-governance-Issues relating to development and management of Social Sector/Services relating to Health and GS paper 4-ethics-ethical concerns and dilemmas in government and private institutions.

News: The article discusses a rare side effect, thrombosis with thrombocytopenia syndrome (TTS), linked to the Oxford-AstraZeneca COVID-19 vaccine.

What is Thrombosis with Thrombocytopenia Syndrome (TTS)?

Thrombosis with Thrombocytopenia Syndrome (TTS) is a rare condition that involves blood clots and a low platelet count. It has been linked to adenoviral vector COVID-19 vaccines like Oxford-AstraZeneca.

For more details information on Thrombocytopenia Syndrome (TTS) read this Article here

What are the risks associated with TTS?

TTS can lead to severe clotting at unusual sites such as the brain or gut, with higher risks in younger populations (Tier 1 cases).

Reports indicate a range from 0.2 to 17.6 cases per million doses over a 21-day period, with significant regional variations.

The fatality rate due to TTS varies, reported between less than 0.1 to 1.3 deaths per million doses in different countries.

How was the COVID-19 vaccine developed?

Adaptive Design: The vaccine was developed using an “adaptive and seamless” design, recommended by the WHO for emergencies. This approach differs from traditional, rigid three-phase clinical trials.

Expedited Trials: The rapid development meant that the detection of very rare side effects, like TTS, was not as feasible during initial trials.

What was the global response?

Suspensions: Many countries, including South Africa and over 20 European nations, temporarily halted the use of the vaccine, especially among younger adults, early in 2021.

U.S. Decision: The United States opted not to approve the vaccine, despite having several million doses stockpiled.

Regulatory Reviews: The European Medicines Agency and WHO conducted reviews and concluded that the benefits of the vaccine outweigh the risks, emphasizing the importance of communicating the specific risks associated with the vaccine.

What are the legal and ethical challenges related to TTS?

Ethical Challenges

Vaccine Suspension Decisions: Different countries made varied decisions about suspending the vaccine, often focusing on younger adults, raising questions about equitable and consistent health policy.

Benefit-risk profile:

The European Medicines Agency (EMA) concluded on March 18, 2021, that the benefits of the vaccine outweighed the risks of rare side effects after reviewing 25 cases of TTS among 20 million vaccinated in the UK and the European Economic Area.

Similarly, the WHO’s Global Advisory Committee on Vaccine Safety confirmed in 2021, a favorable benefit-risk profile based on the data from approximately 47 million doses.

However, the UK High Court is currently evaluating a case involving a compensation claim amounting to £255 million, against vaccine side effects. This case highlights the ethical complexities of balancing public health safety and analyzing the severity and rarity of the side effects.

Question for practice:

Discuss the ethical and legal challenges surrounding Thrombosis with Thrombocytopenia Syndrome (TTS) linked to the Oxford-AstraZeneca COVID-19 vaccine.