The health products regulatory body has issued a safety update about the number of side-effects experienced by people who received vaccinations for Covid-19.

It said that up to 13 May, fewer than five Irish people who had received vaccinations experienced very rare blood clotting events in in the brain in combination with low blood platelets.

These unusual blood clotting events are referred to as thrombosis with thrombocytopenia syndrome.

They were the key side effect recently investigated by the European Medicines Agency, whose study resulted in NIAC’s earlier recommendation to limit the use of the AstraZeneca and Johnson & Johnson vaccines to people over the age of 50 in Ireland.

In today’s safety update the Heath Products Regulatory Authority (HPRA) described the number of such side-effects to date as a very small number, which means it was fewer than five cases.

This is the same description for the number of cases that they reported in their previous safety update last month.

The report says that in all the cases of these very rare blood clotting events in Ireland, symptoms occurred within one to two weeks of a first dose of vaccination.

All occurred in people under 40 years of age and the individuals concerned were discharged from hospital after receiving specialist medical care.

Apart from those very rare type of blood clotting events, the HPRA also received more than 36 reports of other types of blood clotting like those more typically seen in the general population, such as those that occur in the legs (like deep vein thrombosis) and the lungs (pulmonary embolisms).

This brought the total number of blood clot reports from people who received the AstraZeneca vaccine to 41 by 13 May, up from 29 one month earlier.