In Spain, some 100,000 people with weakened immune systems set to receive third Covid-19 vaccine dose

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.

This approach differs from the administration of a third, booster shot for the general population, a process that is underway right now in countries such as Israel, which is giving these doses to the over-50s. For now, there is no scientific evidence to suggest that it is necessary among people with a healthy immune system. The latest studies show that, while vaccines lose efficiency when it comes to avoiding infection after six or eight months, and that a third dose provides greater protection against catching the coronavirus, the protection from two doses against hospitalization or death continues to be high.

Time will tell whether this protection for the most serious forms of Covid-19 will be reduced, making a third dose necessary for wide ranges of the population. But based on current knowledge, both the EMA and ECDC, as well as the experts advising the Spanish government, have advised against this measure for now and are limiting it to the most vulnerable, for whom Covid-19 could put their lives in risk despite having received the two doses.

Health Minister Carolina Darias announced last Wednesday that this step would be taken once the Public Health Commission – made up of the regions and her ministry – ratified it. But it was yet to be seen exactly which sections of the population would be included. As much as 40% of the population could have been slated to receive a third dose, had the commission included everyone with some kind of immune system issue due to illness (such as diabetes, which affects six million people in Spain), age (the body’s defenses are weakened as the years pass, particularly after the age of 80), or if the person is taking medication such as corticosteroids (10% of the population).

English version by Simon Hunter.