Introduction
These days are marking the exact anniversary of the earliest direct
effects of the Coronavirus disease-2019 (COVID-19) pandemic on the
educational sector in the European Union, with Italy as the pioneer
member state. In fact, on March 4th, 2020, the Italian
government issued a ministerial decree that in its first article
declared a nationwide shutdown of pre-schools, schools, and
universities, adapting all didactic activities to distance education. By
March 20th, when the overall prevalence of COVID-19 in
the World Health Organization (WHO) European region was of 151,754 total
reported cases (of which 35% were in Italy, 16% in Spain, 14% in
Germany and 10% in France), 24 (89%) out of the 27 countries making up
the European Union (EU) had fully closed their educational facilities
(with Sweden’s schools being partially open and Slovenia’s and
Bulgaria’s fully open). Worldwide, on the same date, the United Nations
Education, Scientific and Cultural Organization (UNESCO) Global
monitoring of school closures caused by COVID-19 reports a total of 146
country-wide closures, affecting 52.4% of total globally enrolled
learners. By the end of April 2020, the world had witnessed an
unprecedented international disruption of education, with the peak
reached on April 26th, 2020, with 82.9% of total
enrolled learners affected (equal to a total of 1,451,874,449 learners
globally).
As local upsurges of COVID-19 multiplied, so did nationwide lockdowns
and concurrent closure of educational facilities. The decision to close
schools early in the epidemic outbreak relied partly on data collected
from mitigation policies to curb previous pandemics [1] with novel
influenza viruses. In the 1918-1919 influenza pandemic, illness rates
were highest among children of school age, and mortality rates were
highest among infants and young adults other than the elderly [2].
In the 2009 H1N1 virus pandemic children and young adults were once
again disproportionately affected [3]. The indications coming from
already existing disease modelling studies, rapidly supplemented by new
studies published in March-April 2020, evidenced school-closure as a
cost-effective non-pharmaceutical intervention for controlling community
transmission of seasonal and pandemic influenza viruses [4]. This
would be especially noteworthy at a time when documented effective
pharmaceutical interventions were unavailable. Although the evidence on
the effectiveness of such measures during coronavirus outbreaks were
limited, governments acted uniformly in line with the WHO
framework for national and local planning and response to the 2009
pandemic , in which proactive rather than reactive school closures/class
suspension early in a pandemic outbreak were recommended to achieve the
maximal reduction in attack rates. This reduction was expected to be all
the greater if framed within the setting of a general lockdown. The
likelihood of extra-scholastic student aggregation, which hampers the
efficiency of school closures against viral spread, would then be
minimized [5].
Nevertheless, due to multiple associated factors, the correlation
between school closure and reproduction number (Rt) drop might not be so
direct, and such a socially drastic intervention might not always
produce an effect of equally drastic magnitude on incidence,
hospitalizations and deaths. Already at the time when the global
decision to close school was taken, evidence existed to challenge the
effectiveness of school closure in the fight against coronaviruses. A
scientific evidence-based review published in 2014 concluded that the
impact of school closure on the size of the pandemic peak was greatest
for viruses whose transmissibility in the community was low (i.e. with a
basic Rt <2) and whose attack rates were higher in children
than in adults [6]. Neither of these two conditions appeared to be
applicable to Sars-Cov-2 at the start of the outbreak. However, evidence
also existed in a second systematic review from 2018 that school closure
could prove to be a measure on its own to control infectious spread, not
merely a bridge until other measures are found [1].
In the short and medium term, immediate COVID-19 containment was
prioritized over optimal educational continuity and the combined
deployment of all readily amenable interventions did manage to curtail
the first outbreak within the WHO European Region. By May
31st, 2020, incidence and case-fatality ratio
decreased, with 717 deaths out of the 19,995 daily cases as reported to
the WHO compared to the 5,312 daily deaths out of 41,265 daily cases,
which corresponded to the peak of the first wave (registered for the WHO
European region on April 4th, 2020). However, the
steadiness of epidemiological parameters between spring and autumn term,
when schools re-opened in most of Europe, represented only a temporary
hiatus, and a second outbreak started. Although currently the outlook on
the pandemic is still narrow, as new empirical evidence on the severe
acute respiratory syndrome coronavirus 2 (Sars-Cov-2) and its variants
grow on a daily basis, cumulative ongoing research has completely
changed the context in which outbreaks are occurring, gradually
diminishing key unknowns about the virus transmissibility, target
populations, case-fatality, clinical features and available
pharmacological interventions. Mass vaccinations that are occurring
worldwide, and the chronicization of the COVID-19 pandemic, causes a
paradigm shift for paediatricians and whoever else operates in the field
of health promotion for children and adolescents. When considering only
the younger demographic groups, the major problem related to the
pandemic increasingly appears not to be the emergent infectious disease
itself but its long-lasting pervasive indirect consequences. It is our
responsibility to remain updated on both direct and indirect health
effects of COVID-19 on our patient population.
The present literature review will focus on only one such indirect
health effect of the pandemic: the prolonged early school closures and
their precarious re-opening. Early decision-making surrounding
educational facilities across the globe relied on multiple assumptions
and could claim as its main objectives the protection of children, of
educational staff and of the community as a whole from uncontrolled
spread of COVID-19, employing a cost-effective policy. Our aim is to
understand which, if any, of the original assumptions is now fact-based,
and whether the multifaceted latest knowledge on COVID-19 and its
epidemiology in children is accounted for by policymakers, in a world
that has currently lost on average 22 weeks of normal education (UNESCO
data updated to January 25th), and up to more than 50
weeks in some countries (India, USA, Brazil, to cite a few). The large
existing differences in the re-opening policies among different
countries and in the published study types represent an informative
starting point, lessening the risk of both collinearity bias and
population bias compared to literature reviews compiled during the first
wave of the pandemic. School closures were initially used in combination
with multiple other mitigation strategies and testing, as well as
medical care, prioritized symptomatic populations, i.e. including older
adults more frequently than children.
References for this review were initially identified through searches of
PubMed, Scopus and Cochrane Library for articles published from March,
2020, to March, 2021 by use of the terms “Schools” “COVID-19”
“pandemic” “clusters” “outbreak” “seroprevalence”. Further
search was undertaken through Google Scholar and ResearchGate, and
finally through Google. Articles published in English resulting from
these searches and relevant references cited by those articles were then
reviewed.