Around 100,000 people in Spain are about to be administered a third dose of a Covid-19 vaccine. This group is made up of patients with severely suppressed immune systems, and include organ transplant recipients (some 60,000 people), bone marrow transplant recipients (20,000), and patients being treated with anti-CD20 drugs, which are usually used together with chemotherapy to treat lymphomas and other illnesses such as multiple sclerosis, lupus or some types of rheumatoid arthritis (around 150,000 people, but doctors will make the decision as to whether they should get this third shot).
This is the full list of the population that the Health Ministry and the regions decided on Tuesday should receive the third injection, based on the recommendations made by the group of experts advising the government as well as the European Medicines Agency (EMA) and the European Center for Disease Prevention and Control (ECDC).
The reason for administering a third dose to these patients is that their weakened immune system does not sufficiently respond to a dosage considered to offer the full protection of the vaccines among the rest of the population. With two shots of Pfizer-BioNTech or Moderna these patients are still vulnerable (albeit less than they would be without them) to serious illness or death caused by Covid-19. This third injection is not considered a booster, but rather an additional shot to complete the vaccination process.