Spain's healthcare regulator approved on Tuesday a third dose of COVID-19 vaccines for people with severely compromised immune systems who are likely to have weaker protection from the conventional two-dose inoculation schemes.
The so-called booster shot should be administered 28 days after the previous one in some cases, and preferably the same type of vaccine is to be used, the Public Health Commission said in a statement. It would not say how many people could get such shots.
The authority reiterated that there are no solid data available to recommend administering booster shots to the general population.
The European Medicines Agency said earlier this month it was evaluating a potential booster dose of COVID-19 vaccines that may be given six months after the second one.
The World Health Organization has called for a moratorium on COVID-19 vaccine booster shots until at least the end of September to leave more doses available for people in countries with poor access to vaccines.