A plea for an immediate return to open restaurants, mass gatherings and working from the office has received the support of nearly 125,000 petition signatories and opposition from critics who denounce it as dangerous and likely deadly.

The Great Barrington Declaration was written and signed by three epidemiologists in Great Barrington, Mass. on Sunday. Three dozen other scientists, doctors and academics are listed as co-signatories, with the most prominent being Michael Levitt, who won the Nobel Prize for chemistry in 2013.

The declaration lays out the case for global adoption of a "herd immunity"-style approach to the COVID-19 pandemic. It argues that the lockdown-heavy approach is "producing devastating effects" on public health, including "lower childhood vaccination rates, worsening cardiovascular disease outcomes, fewer cancer screenings and deteriorating mental health."

"Keeping these measures in place until a vaccine is available will cause irreparable damage, with the underprivileged disproportionately harmed," it reads.

Instead of long-lasting lockdowns, the declaration argues, governments should shift their focus to achieving herd immunity, which it terms "focused protection" – allowing those at the least risk of serious complications from COVID-19 to be exposed to the virus, while safeguarding those in more vulnerable groups.

The declaration posits that the latter can be achieved by staffing nursing homes with only those who have developed immunity to the novel coronavirus and keeping retirees at home with essential goods being delivered to them, among other measures.

For the rest of the population, it proposes universal adoption of "simple hygiene measures, such as hand-washing and staying home when sick," and a resumption of virtually all pre-pandemic activities, from normal office work to reopened restaurants to sporting and cultural events, in a bid to expose enough people to the virus to build up herd immunity.

LITTLE SUPPORT FOR HERD IMMUNITY

This is essentially the approach that some countries – the United Kingdom and Sweden among them – used as an alternative to lockdowns and similar measures in the early days of the pandemic. The U.K. abandoned that approach in March, while Sweden experienced a high death rate compared to its neighbours while only a small portion of the country's population was conferred immunity. It has been estimated that achieving herd immunity in the United States would mean two million deaths from COVID-19.

The World Health Organization and most major nations' public health leaders have said that a combination of individual prevention, widespread testing and contact tracing, and harsher lockdown-like measures when and where community spread is rampant make for a better approach to combating COVID-19 than letting the virus run rampant in an attempt to build up mass immunity.

Among the issues commonly cited as negatives of a herd immunity strategy are that it is not yet clear if everyone who contracts COVID-19 develops immunity, how long that immunity lasts or if patients can be reinfected. Additionally, even less vulnerable population groups can still die or experience other severe consequences if they contract the virus. While Canadians under the age of 40 represent less than 0.5 per cent of all deaths from COVID-19 in the country, they make up more than 10 per cent of the cases that required time in a hospital's intensive care unit, according to the Public Health Agency of Canada.

Despite the difficulties experienced by nations that prioritized herd immunity over lockdowns, the Great Barrington Declaration has attracted significant support in its first few days online.

As of Thursday morning, it had received just under 130,000 signatures. This includes nearly 8,000 signatures claiming to be from "medical professionals" and more than 4,300 claiming to be from "medical and public health scientists," although anyone signing the declaration is able to assert that they fit into either of those categories.

More than 5,000 of the signatories claimed to be from Canada.

The declaration has also been endorsed on Twitter by conservative politicians in the U.S. and the U.K., as well as independent Ontario MPP Randy Hillier.

Opposition has come primarily from scientists and public health experts. Gregg Gonsalves, an assistant professor at the Yale School of Public Health, described the declaration as "wrong in so many ways" in a tweet thread, arguing that it would essentially kick the elderly, the immunocompromised and those living with disabilities out of society.

Michael Head, a senior research fellow in global health at the University of Southampton in the U.K., said in a statement that the declaration only makes sense as an argument against full lockdowns that last until a vaccine is ready – something that is not currently in place or being proposed anywhere.

"There are countries who are managing the pandemic relatively well, including South Korea and New Zealand, and their strategies do not include simply letting the virus run wild whilst hoping that the asthmatic community and the elderly can find somewhere to hide for 12 months," he said.

"Ultimately, the Barrington Declaration is based on principles that are dangerous to national and global public health."