OVIEDO, Spain

As new coronavirus cases continue to drop in Spain, data released by the Health Ministry on Friday suggest that schools have become the leading source of clusters over the last week.

Looking at the 1,678 coronavirus outbreaks detected over the last week in Spain, schools were the main focal point for contagion, overtaking for the first time other single settings like social or family gatherings, nursing homes, healthcare centers or workplaces.

The Health Ministry did not comment on the reason for this, but several factors are likely influencing the figures.

First, most regions of Spain have enacted measures that limit the number of people allowed to gather. Bars, restaurants and gyms have likewise seen limitations and the country is under curfew, with an aim to reduce social activities.

However, throughout a devastating third wave of cases, Spain opted to leave its schools open.

Although schools came in the top spot for contagion this week, the number of educational clusters has very slightly fallen for the last two weeks in a row -- just at a much slower pace than in other settings. Classroom contagions are still near a record-high.

At the same time, the site of many of the most devastating outbreaks has in the past been in nursing homes. As soon as Spain received its vaccines against the virus, its top priority became vaccinating nursing home residents and workers.

This week, Spain's chief epidemiologist said, also for the first time, that the COVID-19 infection rate was lower in senior citizens who lived in nursing homes than in those who lived at home.

Several regions of Spain finished vaccinating nursing home residents this week with their second doses. Mortality has likewise plummeted in this group.

There are also concerns about variants. In the city of Elda, 200 young students were confined this week, due to what the center called "a highly contagious" strain of coronavirus.

Around 20-25% of all cases in Spain are now estimated to be caused by the UK variant, though this is much higher in some areas. Research suggests that the strain is more contagious both in children and adults, though no evidence suggests it targets children particularly.

The data has also not picked up all sources of infection. Spain reported 11,435 new infections on Friday alone, while the data only included less than 10,000 cluster-related cases during a seven-day period.

Meanwhile, the Health Ministry reported another 397 COVID-19 deaths as hospitalizations continued to decline.

In total, nearly 3 million vaccine doses have been administered, with 1.17 million people having received the full two shots.