Would Herd Immunity Save Lives?

The findings suggest that while strict public health measures bring cases down, in the long run, the number of deaths rise.

Sweeping lockdowns across the U.K. could lead to more COVID-19 deaths and a prolonging of the pandemic than if the government were to let herd immunity build up in young populations, a new study suggests.

Researchers published a reanalysis of data modelling the British government used as guidance for instituting blanket lockdowns and social distancing measures in March, at the beginning of the pandemic.

The findings, published in the British Medical Journal last Wednesday, suggest that while strict public health measures bring cases down, in the long run, the number of deaths rise. Read it here: https://www.bmj.com/content/371/bmj.m3588##

In one simulation, the researchers ran a model that showed lockdowns, social distancing of those older than 70, and quarantining the sick all significantly stunted the spread of the virus in a first wave. However, when those measures are scaled back, infection rates bound upwards, especially in young people, and push the model into a deadlier second wave.

In that deadlier second wave, young people, who are less susceptible to dying from COVID-19, had helped spread the virus to older populations, who subsequently saw higher rates of death.

The authors described the model as a postponement of the pandemic.

But, at a media briefing on Monday, the head of the World Health Organization, Tedros Adhanom Ghebreyesus, said that allowing the novel coronavirus to spread in an attempt to reach herd immunity was “simply unethical.”

The remark was a rebuke of herd immunity amid the most rapid rise in cases since the pandemic began in March.

“Never in the history of public health has herd immunity been used as a strategy for responding to an outbreak, let alone a pandemic,” said Tedros, the WHO Director-General. “It is scientifically and ethically problematic.”

Antibody studies suggest that fewer than 10% of people in most countries have contracted covid-19, he said, which is nowhere near the majority that would be needed for herd immunity.

With the majority of the world’s population susceptible, letting the virus spread “means allowing unnecessary infections, suffering and death,” he said.

Significantly fewer deaths

In a different mode in the U.K. study, where lockdowns are removed and younger people are allowed to go to school and work, while those above age 70 are made to social distance and stay put, the models show significantly less deaths.

“Lockdown does mean that the number of deaths goes down, so there is a short-term gain, but it leads to long-term pain,” the lead author Graeme Ackland, a computer simulation professor at the University of Edinburgh told The Telegraph.

“If you had done nothing, it would all be over by now. It would have been absolutely horrendous but it would be over. It wouldn’t even have been completely lunatic to do nothing.”

In the study, the authors suggest that rather than sweeping lockdowns and generalized social distancing, young people should be allowed to go to school while older groups are made to quarantine. This would allow young people to build up a herd immunity while also protecting the most vulnerable populations.

With files from The Washington Post