Germany and Canada restrict AZ vaccine over blood clot fears

Germany and Canada have both slapped restrictions on the AstraZeneca vaccine, recommending its use only in older patients, because of concerns over a link with blood clots.

The moves come after the country’s medicines regulator found 31 cases of a rare type of blood clot known as cerebral venous sinus thrombosis (CVST) in people who had received the vaccine produced by AZ.

The decision to restrict use of the shot in under-60s comes from Germany’s independent vaccine committee known as STIKO made the decision based on available data about the blood clotting events.

The decision runs counter to central guidance from the European Medicines Agency’s safety committee, which earlier this month said the AZ vaccine was safe and effective following a thorough review including incidences of CVST.

It is also a reversal of a previous position, where German authorities said that the AZ vaccine should not be used in patients in over 65, because of the smaller number of older patients in the first trials of the shot.

According to STIKO the side effect occurred four to 16 days after vaccination and was predominantly seen in people under 60 years of age.

The committee will address the issue of whether younger people who have already received a first dose of the AZ vaccine.

Germany’s Paul Ehrlich Institute said that within the 31 cases of CVST, there were 19 cases of thrombocytopenia.

Of those nine cases of thrombocytopenia, nine of the people affected died.

All but two of the 31 cases involved women aged 20 to 63 while two men affected were 36 and 57 years old, the institute said.

The decision had a knock-on effect: Canada’s National Advisory Committee on Immunization (NACI) also suspended vaccinations in those aged under-55s in updated guidance published earlier this week.

Several provinces have now suspended use of the vaccine for anyone below the age of 55 while Health Canada, the country's central regulator, assesses the risk.