• Only 3% to 4% of the population has been infected by the coronavirus, meaning most people still are vulnerable
  • Swift imposition of lockdowns reduced the infection rate by 82%
  • Curiously, shutting schools had little impact on the virus' spread

Two studies published Monday in Nature indicate aggressive action that shut down the world economy prevented more than 500 million more infections in six countries, reducing infection rates by 82% and saving millions of lives.

A study by the Imperial College of London indicates only 3% to 4% of the populations in 11 European countries have been infected by the virus, meaning the vast majority of the population still is vulnerable. The other study, which focused on China, the United States, France, Italy, Iran and South Korea, concluded orders forcing people to stay at home changed the infection trajectory, averting 62 million infections among those who were tested for the virus and extrapolated that number to 530 million because most infected people never get tested.

“This is just the beginning of the epidemic: We’re very far from herd immunity. The risk of a second wave happening if all interventions and precautions are abandoned is very real,” Samir Bhatt, senior author of the Imperial College London study, told the Washington Post.

The study estimates as many as 15 million Europeans had been infected with the coronavirus by May 4.

“Our results show that major non-pharmaceutical interventions and lockdown in particular have had a large effect on reducing transmission. Continued intervention should be considered to keep transmission of SARS-CoV-2 under control,” the study said.

The U.S. study concluded imposition of shutdown orders was crucial in stemming the infection rate and urged countries around the world that still are in early stages of the outbreak not to wait.

“The economic costs of shutdowns are highly visible -- closed stores, huge job losses, empty streets, food lines. The health benefits of the shutdowns, however, are invisible, because they involve people not sickened,” the study said.

The researchers looked at 1,717 local, regional and national actions to see which were effective in stemming spread of the virus. They said in the early stages of the pandemic, infection rates grew 43% per day, but, curiously, shutting schools was not an effective means of stemming the spread.

“During the early stages of an epidemic, a large proportion of the population remains susceptible to the virus, and if the spread of the virus is left uninhibited by policy or behavioral change, exponential growth continues until the fraction of the susceptible population declines meaningfully,” they noted, saying infections were reduced dramatically once lockdowns were instituted, with elimination of large gatherings the most effective way of reducing infection rates.

Few places in the world are untouched by the virus, with St. Pierre and Miquelon reporting just a single case, and Montserrat, Papua New Guinea, the British Virgin Islands, Lesotho, the Seychelles; Bonaire, Sint Eustatius and Saba, St. Barthélemy, and Anguilla reporting fewer than a dozen.

Worldwide, more than 7 million infections have been confirmed along with nearly 410,000 deaths.