The study, published Monday in the scientific journal Nature, involved a modeling technique generally used to estimate economic growth to measure the effect of closure policies in six countries: China, South Korea, Italy, Iran, France and states -United.
These estimates suggest that, without certain policies in place from the start of the pandemic in January until the beginning of April, there would be roughly:
Overall, the study suggests that Covid-19’s emergency policies have prevented more than 500 million total coronavirus infections in the six countries.
“The past few months have been extraordinarily difficult, but thanks to our individual sacrifices, people around the world have each contributed to one of humanity’s greatest collective achievements,” said Hsiang in the press release.
“I don’t think human endeavor has ever saved so many lives in such a short time. There have been huge personal costs to stay home and cancel events, but the data shows that every day has made a big difference, “Hsiang told me. “By using science and cooperating, we have changed the course of history. “
The study, conducted by researchers at UC Berkeley, included data in six countries on daily infection rates, changes in case definitions of coronavirus and the timing of 1,717 policy deployments – including travel restrictions, social distancing measures and home stay bans – – from the earliest dates available this year until April 6.
The researchers analyzed this data to estimate how the daily growth rate of infections could have changed over time in a specific location if there had been different combinations of large-scale policies. Data showed that, outside Iran, the rate of infection growth was around 38% per day on average before policies slowed the spread.
Researchers have found that, in all six countries, stop interventions have prevented or delayed a total of about 530 million infections – which, according to testing procedures and case definition, translates by approximately 62 million confirmed cases.
The researchers did not estimate how many deaths could have been prevented.
“Our analysis focuses on confirmed infections, but other findings, such as hospitalizations or deaths, are also of political interest. Future work on these results may require additional modeling approaches as they are relatively more context and state dependent, “the researchers wrote. in the study.
The study had some limitations, including the fact that the data available on infections and measures across countries were limited and the study can only suggest estimates of what might have happened.
“Our empirical results indicate that large-scale anti-contagion policies are slowing the COVID-19 pandemic,” the researchers wrote in the study. “Because infection rates in the countries we study would have initially grown exponentially rapidly if no policy had been applied, our results suggest that these policies have brought significant health benefits. “
Although this study did not include an analysis of the deaths of Covid-19, a separate study that also released on Monday looked at deaths across Europe.
In 11 European countries, school closings and closings that were put in place in response to the coronavirus pandemic may have prevented about 3.1 million deaths in early May, according to estimates by another modeling study.
The study, also published in the journal Nature, suggests that in these European countries, between 12 and 15 million people were infected with the coronavirus until May 4, which represents between 3.2% and 4% of the population.
The study, conducted by Imperial College London, involved calculating coronavirus infections from observed deaths, and that death data were used to model changes during Covid-19 since the start of the pandemic until May 4, when the blockages began to be lifted. .
The countries included in the data were: Austria, Belgium, Denmark, France, Germany, Italy, Norway, Spain, Sweden, Switzerland and the United Kingdom.
The study had some limitations, including the fact that deaths from Covid-19 at the start of the pandemic could have been omitted from the data, and there are variations in the reporting of deaths by country.
“Using a model based on the number of deaths in 11 European countries, it is clear to us that non-pharmaceutical interventions – such as school closings and closings – have saved approximately 3.1 million lives in these countries, “said Seth Flaxman. , a senior lecturer in the mathematics department of Imperial College London, who worked on the study, said in a press release on Monday.
Flaxman added: “Our model suggests that the measures put in place in these countries in March 2020 succeeded in controlling the epidemic by reducing the number of breeding animals and considerably reducing the number of people who would have been infected with the virus” .