• The results show a marginal rise in risk following viral vaccinations.
• When planning future vaccine development and organising immunisation campaigns, it should be taken into consideration.
• Based on routinely gathered health information for more than 10 million adults, they came to their conclusions.

According to a study, researchers have learned more about the possibility of acquiring an extremely rare blood clotting disorder after receiving a vaccination against COVID-19. The study showed an elevated risk of the illness known as thrombosis with thrombocytopenia syndrome (TTS) after receiving the first dose of the Oxford-Astrazeneca vaccine, according to health data from five European nations and the US. 

In comparison to the Pfizer-BioNTech vaccination, the study, which was published in The British Medical Journal (BMJ), also suggests an increased risk following the Janssen/Johnson & Johnson vaccine. Although the illness is extremely unusual, the researchers emphasised that the dangers should be taken into account when developing new vaccines and planning future immunisation campaigns. 

It is extremely uncommon and distinct from common clotting diseases like deep vein thrombosis (DVT) or lung clots, the report claims. The adenovirus-based Covid vaccines, which use a weakened virus to elicit an immune response against coronavirus, are now being researched for TTS as an uncommon side effect, but the study found that there is no conclusive proof about the relative safety of various vaccine types.

 An international team of scientists set out to assess the risk of TTS or thromboembolic events linked to the use of adenovirus-based Covid vaccines with mRNA-based Covid vaccines in order to fill this information gap. Based on routinely gathered health information for more than 10 million adults in France, Germany, the Netherlands, Spain, the UK, and the US who received at least one dose of a Covid vaccine (Oxford-AstraZeneca, Pfizer-BioNTech, Moderna, or Janssen/Johnson & Johnson) between December 2020 and mid-2021, their conclusions were made. 

Additionally, to reduce the possibility of error, participants were matched by age and sex, and a variety of other potentially significant characteristics, such as pre-existing diseases and medication use, were taken into consideration. The rates of thrombosis and thrombosis with thrombocytopenia were then compared between the mRNA vaccines (Pfizer-BioNTech or Moderna) and the adenovirus vaccines (Oxford-AstraZeneca or Janssen/Johnson & Johnson) within 28 days of vaccination.