Canada's National Advisory Committee on Immunization recommended Monday, March 29 that the AstraZeneca Covid-19 vaccine should not be used in adults under age 55 while rare cases of serious blood clots following vaccination are being investigated, according to a release from the committee, CNN reports.

The rare cases of serious blood clots, known as vaccine-induced prothrombotic immune thrombocytopenia (VIPIT), have recently been reported in Europe following post-licensure use of the AstraZeneca vaccine, primarily in women under the age of 55.

According to the vaccine committee, the rate of this adverse event is still to be confirmed and information is being gathered to be more accurate.

"Following population-based analyses of VIPIT assessing risk of Covid-19 disease by age, and considering that alternate products are available (i.e., mRNA vaccines), from what is known at this time, there is substantial uncertainty about the benefit of providing AstraZeneca COvid-19 vaccine to adults under 55 years of age given that the potential risks associated with VIPIT, particularly at the lower estimated rates," committee officials said.

As a precautionary measure, while Health Canada carries out an updated risk versus benefit analysis based on emerging data, the committee is recommending that the vaccine not be offered to adults younger than 55 but will continue to reassess based on "rapidly evolving evidence."

It was reported earlier that the first batch of 24,000 doses of AstraZeneca's Covid vaccine have been imported to Armenia through COVAX facility. Authorities said the shots will be used to vaccinate people aged over 65, those who have underlying health conditions, medical workers, residents and staff of elderly care centers, as well as social care center employees.