Researchers in Canada have claimed to have demonstrated an effective treatment for a rare blood clot caused by the Covid-19 vaccine made by AstraZeneca, which is also manufactured under the brand name Covishield by the Pune-based Serum Institute of India (SII).
Scientists at the McMaster Platelet Immunology Laboratory (MPIL), which is part of the faculty of health sciences at McMaster University in Hamilton in the province of Ontario, recommended "two treatments, a combination of anti-clotting drugs with high doses of intravenous immunoglobulin" to combat the adverse side-effect - vaccine-induced immune thrombotic thrombocytopenia (VITT).
"The use of high-dose intravenous immune globulin (IVIG) plus anticoagulation is recommended for the treatment of VITT, a rare side-effect of adenoviral vector vaccines against Covid-19," they said in a study published in New England Journal of Medicine.
The university described it as a "new lifesaving treatment".
MPIL's scientific director and associate professor of medicine Ishac Nazy said, "If you were a patient with VITT, I'd be telling you, we know of a treatment approach. We can diagnose it accurately with our tests, treat it, and we know exactly how the treatment works."
MPIL is the only laboratory accredited by Canadian health authorities to test treatments for this rare condition. There have been 28 such cases officially reported in Canada so far, including five fatalities.
MPIL researchers devised an "effective VITT test and treatment by building on their previous investigations of heparin-induced thrombocytopaenia (HIT)," the release said. Scientists modified their HIT test to "detect VITT-specific antibodies that are found, albeit rarely, in patients who had a Covid-19 vaccine".
Following that, tests on blood samples taken from three Canadian patients who were suffering from the side-effect "showed how high doses of immunoglobulin coupled with blood-thinner medications shut down platelet activation and stopped clot formation".
Nazy said, "We now understand the mechanism that leads to platelet activation and clotting."
Around 2.8 million doses of the AZ vaccine have been administered to Canadians, including 500,000 doses of Covishield.
While the number recorded as having suffered from adverse reactions was minuscule, health authorities like those in Ontario had paused use of the vaccine in mid-May.
The vaccination drive has now resumed for second doses, though the National Advisory Committee on Immunisation updated its recommendation earlier this month to say that the first dose of the AZ vaccine can be followed by a second jab of a Pfizer or Moderna shot.