Spain's health ministry said on Wednesday that people under the age of 55 without major health complications who have previously contracted the coronavirus will have to wait six months from their diagnosis before receiving a vaccine.
The measure, which appears to be unique in Europe, will apply to the three vaccines currently being distributed in Spain and is provisional pending further research.
Justifying the decision to prioritise those without a history of COVID-19, the ministry said that cases of reinfection within six months are "exceptional".
A major British study published last week found 99% of participants who had previously tested positive retained antibodies for three months, while 88% still had them after six months.
People older than 55 or those with health risks that make them more vulnerable to reinfection will be exempted from the delay, the ministry said.
So far, the only people under 55 being vaccinated are health-care professionals, according to Spain's recently updated vaccine strategy, which also recommends not taking an antibody test prior to vaccination.
Elsewhere in Europe, several Italian epidemiologists have said it is useless to vaccinate those who have already been infected, but Rome has not taken any decision on whether to administer jabs to recovering patients.
And France's public health agency believes there is no need to inoculate people who developed a symptomatic form of the disease, although those patients can still opt to take a shot three months after the onset of symptoms.