Doctors are honing in on the situation of blood clots that could be linked with particular coronavirus vaccines and add their findings have important implications regarding treating the condition, regardless of the company that developed the vaccines, CNN reported.
Though there is no official term for the situation yet, it is known as vaccine-induced immune thrombotic thrombocytopenia or VITT.
It manifests as an unusual blood clotting combined with a low number of blood-clotting cells known as platelets. Patients manifest dangerous clots and, occasionally, haemorrhaging at the same time.
It was linked most firmly with the AstraZeneca coronavirus vaccine, which is widespread in Europe and the UK.
The US Centers for Disease Control and Prevention and the Food and Drug Administration analyze if the Johnson & Johnson vaccine also may provoke blood clots.
Both Johnson & Johnson and AstraZeneca’s vaccine use common cold viruses known as adenoviruses as a carrier. Some health experts believe that the body’s response to those viral vectors may underlie the reaction.
The AstraZeneca vaccine isn’t authorized in the US.
The CDC and FDA asked for a pause in vaccinating people with J&J while looking for the source of the problem and maybe elaborating a potential solution.
A team conducted by Dr Marie Scully, a haematologist from the University College London Hospitals, analyzed 22 patients who manifested the syndrome after getting vaccinated with AstraZeneca shots.
The anti-PF4 antibodies were only seen before in a rare reaction to the use of standard blood thinner heparin.
The findings suggested a theory that an immune reaction could underlie the rare blood clots. However, the findings don’t fully explain it, as Scully and colleagues made it public in the New England Journal of Medicine Friday.
According to them, if vaccines are the actual reason behind the blood clots, it is still an infrequent and peculiar event.
It may not even be occurring among recently vaccinated people anymore.
“The risk of thrombocytopenia and the risk of venous thromboembolism after vaccination against SARS-CoV-2 do not appear to be higher than the background risks in the general population, a finding consistent with the rare and sporadic nature of this syndrome,” they stated.
They explained that the events reported in the study seem to be rare. Until further analysis is conducted, it is tough to predict who may suffer from the symptoms, as they occurred more than five days after the first vaccine dose was administered.
In all cases documented to date, thrombosis (blood clot) and thrombocytopenia (low platelet count) seem to be triggered by the first dose of the AstraZeneca shot.
Though there have been numerous reports after the receipt of other vaccines against SARS-CoV-2, none was confirmed to fulfil the diagnostic criteria, the team noted.
Patients must be given anti-clotting drugs, but not heparin, and infusions of a blood product known as intravenous immunoglobulin can potentially replace the depleted platelets.
Also, it isn’t obvious who is at the highest risk.
“Most of the patients included in these reports were women younger than 50 years of age, some of whom were receiving estrogen-replacement therapy or oral contraceptives. A remarkably high percentage of the patients had thromboses at unusual sites,” wrote Dr Douglas Cines of the University of Pennsylvania and Dr James Bussel of Weill Cornell Medicine.
Some European countries have also restricted who gets vaccinated with the AstraZeneca vaccine.
Belgium, for example, only uses it for people under the age of 55.