Only five percent of Spain's population has been infected by the novel coronavirus, though that figure climbs to more than 10 percent in Madrid and areas in the centre of the country, according to a study released by the government on Wednesday.
Spain is one of the hardest hit nations in the global pandemic, with more than 27,000 deaths and around 228,600 cases confirmed by testing since the outbreak began in China late last year.
The study launched on April 27 was based on serology tests to show exposure to coronavirus and took samples from 60,000 people.
"The study found five percent of the Spanish have been in contact with the virus, a little more than two million people," Health Minister Salvador Illa said.
Some studies have shown that a portion of people infected by the virus will show no symptoms, but can still transmit the disease.
The Spanish study confirmed that the virus circulated more in the centre of the country, which paid the highest price in fatalities.
In Madrid, the rate of infection was 11.3 percent, in Barcelona it was 7.1 percent, but only 2.3 percent in Seville, according to the study.
The Spanish government has so far released only the results of a first wave of "rapid tests" to determine the level of antibodies as a way to ascertain who has been infected.
A similar study published on Wednesday in France showed that less than 10 percent of the population had been contaminated in the Paris region and in the northeast, the two areas most affected in France. That compared with 4.4 percent nationally.
The novel coronavirus has killed at least 294,199 people since the outbreak first emerged in China last December, according to a tally from official sources compiled by AFP at 1900 GMT Wednesday.
At least 4,305,340 cases have been registered in 196 countries and territories worldwide. But those are likely only a fraction of the true number of infections because of low levels of testing.