The changed calculation reflects the arrival of the more contagious coronavirus variant, first identified in the UK, which has created astonishing increases in cases and put pressure on medical systems across the continent.
The basic scientific thinking in Europe in schools is pretty much the same. When students and teachers wear masks, ventilation is good and mixing between classes is minimized, classrooms are still believed to be relatively safe and play a small role in fuel outbreaks compared to places like nursing homes, prisons, food processing plants, restaurants and bars.
But the variant has increased the threat everywhere, even in schools.
“In itself, schools are not the main problem, but it makes sense to close them when the number is so high that everything can affect the health system as a whole,” said Celso Cunha, director of the medical microbiology unit at the Nova University of Lisbon Institute of Hygiene. and tropical medicine.
Portugal, which sees the highest daily cases and deaths of coronavirus per capita. Populated on the continent, is the latest European country to give in to schools.
Portuguese classrooms had remained open even when the government imposed a strict national shutdown this month. Prime Minister António Costa had said he would “protect and guarantee the education of this generation” and avoid the “social costs” of sending students home.
But days later he turned around. The variant had expanded from 8 percent to 20 percent of coronavirus cases in Portugal within a week, and the government decided that everything should be shut down.
“Despite the extraordinary efforts made by the schools to prepare,” Costa said, “in light of the new burden, the precautionary principle requires that we continue with a school drop-out.”
CDC researchers looked at Europe’s experiences this autumn to inform theirs conclusion that “there has been little evidence that schools have contributed meaningfully to increased transmission of society.”
The return of the fall to classrooms was not a major driver of Europe’s second coronavirus wave, The European Center for Disease Prevention and Control has said, and transmission in school seemed to remain relatively uncommon, especially at the primary school level.
However, although schools do not play a significant role in speeding up the spread of the virus, epidemiologists say that schools tend to reflect the viral situation in a society. More infections in a city means that more infections will appear in its schools, increasing the risk and disruption.
In addition, many countries in Europe since the fall have found that when everything else is locked and students continue to go to class, schools can continue to feed cases when the virus disappears elsewhere.
This concern is acute in connection with the variant.
“If the government reaches the stage where they say no one should move around, it should include children,” said Quique Bassat, a pediatrician and epidemiologist who coordinated the Spanish Pediatric Association’s working group on school reopening.
Some prominent European virologists have been of the opinion that it is a great risk to keep schools open, including the director of the Department of Virology at the Charité Hospital in Berlin, Christian Drosten, who has inspired a rock star-like entourage in Germany comparable to that of Anthony S. Fauci and USA.
Large-scale statistical analyzes examining trends across recent studies show that children aged 10 and under are about half as likely to catch the virus compared to adults. Studies are less crucial to how likely infected children are to transmit the virus to someone else.
While initial reports suggested that children may transmit the new variant as easily as adults, subsequent contact tracing of Public Health England documented that children, as with the original virus, are less likely to be vectors, with the effect exacerbated in adolescence .
But British studies suggest that the new strain is between 30 and 70 percent more contagious, an effect seen across age groups, so both students and teachers may be at greater risk.
At Willibrord Primary School outside Rotterdam, tests after an outbreak in late November found at least 123 cases of coronavirus among teachers, students and family members – 15 percent of those tested. All the students ‘and teachers’ cases that were sequenced turned out to be the more transferable variant, and researchers are trying to determine whether the school is responsible for the wider spread of the variant, known as B.1.1.7, in the region. However, the students were not wearing masks or taking other distance measures, factors that would have contributed to the spread of the virus. Dutch schools closed in mid-December, a few weeks after the eruption in Rotterdam.
Just across the border, Belgium has opted for the opposite approach and closed its schools for three weeks at the top of a worst world record in November, but otherwise left the lower grades in session. High schools have had more distance learning.
Over the past week, confirmed cases in Belgium generally fell by 19 percent, but cases among children up to 9 years increased by 88 percent. Although the increase can be partly explained by more tests in primary schools, it may also be related to students continuing to go to class. Absenteeism is growing among both teachers and students, an apparent repeat of a similar trend in October, when so many teachers were ill or quarantined that it became difficult to keep classrooms in normal operation.
“Obviously, reopening schools in a moment where the balance is very fragile may be the element that will put you on one side or the other,” said Emmanuel André, a Belgian virologist who has advised his country government about its pandemic. response. “If you have a fragile balance, you will always play on the safe side, because if it is fragile, it can break, and if it breaks, it can go fast.”
But he said he still preferred to keep schools open until further notice.
“After a year of crisis, all these choices are balanced between public health and social well-being,” said André.
The World Health Organization has also recommended closing schools as a last resort.
When cases grow rapidly despite all the other measures taken to slow down viral growth, “closing schools may unfortunately be the extra step, the last push” to make case numbers shrink again, said Catherine Smallwood, a senior health worker at the World Health Organization.
“Variant or no variant, the ambition should be to keep schools open,” she said.
Some countries in Europe still say that they can safely maintain personal training, even if the more transferable variant is set to overtake them. But many countries have withdrawn to close schools.
Ireland did so this month as the country registered a wild increase in cases; reports suggest that students may not return to classrooms much before Easter.
In England, classes were only back in session shortly after the winter break before Prime Minister Boris Johnson announced they would close.so far“To slow down the spread of the variant.
In Germany, schools closed in mid-December as cases rose. The federal education minister warned this month not to expect a quick return for face to face teaching for all students.
In Denmark – the first country in Europe to send students back last year – politicians left schools closed after the winter break, even though cases fell because they try to get cases as low as possible to better control the wave when it comes.
And Austrian students have been learning at home since November.
The increased availability of vaccine doses in the United States may make a difference in school openings, as U.S. teachers are already eligible for vaccination in some states. It would make schools safer for the adults who work in them. Europe, on the other hand, is facing a shortage of vaccines and has gone no further than inoculating healthcare professionals, those in nursing homes and the elderly.
But as in Europe, momentum in the United States may change if the variant takes hold.
Bassat, the Spanish pediatrician, said that even with the more contagious variant circulating through Spain, they had not yet seen major outbreaks in schools that have been open with strict security measures. He thought it might be a good signal for the United States.
“We are not the kings of the organization,” he said. “If we have managed to do it without necessarily using big things and crazy things, then anyone can do it.”
Birnbaum reported from Riga, Latvia. Quentin Ariès in Brussels contributed to this report.