The change is contained in a new update to IPST's contingency plan for the sustainability, quality and safety of the blood and blood component supply during the Covid-19 pandemic.

"Potential blood and blood component donors vaccinated with mRNA vaccines, (primary vaccine scheme or booster dose) can be accepted as blood donors if they feel well and are asymptomatic," the document said.

As for the people who are candidates for donation who have had Covid-19, they still have to "wait 14 days after the resolution of symptoms to apply again," the institute said in a statement.

The contingency plan also said there is no scientific evidence of complications in the donation or administration of substances of human origin that could be attributable to the vaccination of the donor.

"At the time of this update, there continues to be no evidence of transmission of this virus through transfusion. No cases of respiratory virus transmission, including SARS-CoV-2, have been reported through substances of human origin or plasma-derived drugs, nor has there been a report of increased morbidity and mortality from Covid-19 in recipients of blood and blood component transfusions," the IPST contingency plan states.

In recent days, the IPST has appealed to the contribution of all potential donors, at a "particularly demanding time" due to the Covid-19 pandemic and "a great difficulty in maintaining stable reserves of blood components".

"The evolution of the Covid-19 pandemic, particularly the high number of infections in recent weeks and respective prophylactic isolations, have led to a great difficulty in maintaining stable reserves of blood components," said the institute.

To be a blood donor, you just need to be between 18 and 65 years old - the age limit for the first donation is 60 years old - and weigh 50 kilos or more.