A Quebec woman is the first in Canada to develop a blood clot after being vaccinated with the Oxford-AstraZeneca vaccine.

The woman received the vaccine produced at the Serum Institute of India, known as Covishield, and is recovering at home, the Public Health Agency of Canada said Tuesday.

Reports of blood clots with low platelets in people who received the shot are very rare, PHAC said.

Last month, federal officials limited the use of AstraZeneca's COVID-19 vaccine, launching an investigation into reported links to a rare blood clot condition known as VIPIT.

The National Advisory Committee on Immunization said the vaccine should not be used by people younger than age of 55, while Health Canada issued guidelines around what to look for if you suspect you have had an adverse reaction.

Here’s a look at this rare condition.

WHAT IS VIPIT?

VIPIT stands for: Vaccine-Induced Prothrombotic Immune Thrombocytopenia. According to NACI, it is associated with the development of antibodies that "activate" platelets, which stimulate the formation of blood clots.

HOW DANGEROUS IS VIPIT?

The case fatality of VIPIT is approximately 40 per cent, however that may decrease with increased awareness and early treatment.

HOW COMMON IS THIS ADVERSE REACTION?

Data from the European Medicines Agency suggests an incidence rate of one per 100,000 shots across Europe thus far.

WHO DOES THIS AFFECT?

So far, cases have largely been among women younger than age 55 and mostly emerged between four and 16 days after vaccination. However, a brief for Ontario's COVID-19 advisory group notes many European countries used more of their initial AstraZeneca doses in women under age 55, which may have skewed the results.

The provincial science table experts add that VIPIT does not appear to be more common in people who have had blood clots before, have a family history of blood clots, have a low platelets, or pregnant women.

ARE THERE KNOWN CASES IN CANADA LINKED TO THE ASTRAZENECA VACCINE?

Yes. A Quebec woman was reported Tuesday as the first in Canada to develop a blood clot after being vaccinated with the Oxford-AstraZeneca vaccine.

WHAT ARE THE WARNING SIGNS?

Experts say to look for the following symptoms between four and 20 days after vaccination: a severe headache that does not go away; a seizure; difficulty moving part of your body; new blurry vision that does not go away; difficulty speaking; shortness of breath; chest pain; severe abdominal pain; new severe swelling, pain, or colour change of an arm or a leg.

This report by The Canadian Press was first published April 13, 2021.

News from © The Canadian Press, 2021