Public health campaigns and school closures were among the most effective ways to control the spread of Covid-19, according to a German research institute.
Together those measures reduced the reproduction rate, the average number of people one person with the virus goes on to infect, known as the R-value, by 0.35 and 0.24, respectively, said the Kiel Institute for the World Economy.
But just because a strategy works does not necessarily mean it should be recommended, the study's authors said, as school closures in particular resulted in other harms.
“The high effectiveness of a measure does not automatically translate into a recommendation for political implementation if it has, as in the case of school closures, strong negative effects,” said Alexander Sandkamp of the Kiel Institute.
He teamed up with Anthonin Levelu of Paris Dauphine University to analyse 14 “non-pharmaceutical interventions” and their association with the R-value in 182 countries in 2020, using statistical methods, to produce a Kiel working paper: “A lockdown a day keeps the doctor away: The effectiveness of non-pharmaceutical interventions during the Covid-19 pandemic”.
Other effective measures to reduce the reproduction rate, or R-value, of the virus included Covid-19 testing (-0.23), contact tracing (-0.15), and international travel restrictions (-0.14).
The cancellation of public events, remote working, and introducing a cap on the maximum number of people who can mingle also lowered the R-value.
Masks did not “produce statistically measurable success in the first wave” but were more effective in the second.
Local travel restrictions had “no measurable effect on infection control,” said the study authors.
“However, the decision on which measures to implement [first] also depends on their economic and social impacts,” said Mr Sandkamp, who does research on international trade at the Kiel Institute.
“Measures that are effective while causing relatively few distortions should be implemented first, such as information campaigns, testing, contact tracking, and mask wearing.”
Education disrupted by school closures
School closures were widely implemented across the world as Covid-19 spread in 2020.
According to research by Save the Children, in the following year children globally lost more than a third of the typical 190-day school year because of the coronavirus pandemic.
And during the peak of the pandemic in 2020, 91 per cent of the world's learners were locked out of schools, according to a review by Save the Children of Unesco's research.
Studies found the closures had an adverse impact on children’s mental and physical health, with long-term consequences.
Research led by Great Ormond Street Institute of Child Health in London examined 36 studies in 11 countries around the world, involving about 80,000 children and 18,000 parents, to assess the impact of lockdowns and school closures.
They found increased levels of anxiety and depression among young people.
“There was consistency in findings across studies, particularly for mental health, with almost all studies documenting poorer mental health and well-being,” the researchers said.