Hoping for herd immunity to tackle Covid-19 is ‘ethically problematic’


World Health Organization (WHO) Director-General Tedros Adhanom Ghebreyesus  (Photo: FABRICE COFFRINI/AFP via Getty Images).
World Health Organization (WHO) Director-General Tedros Adhanom Ghebreyesus (Photo: FABRICE COFFRINI/AFP via Getty Images).

THE World Health Or­ganization (WHO) chief warned on Monday (12) against just allowing the coronavirus to spread in the hope of achieving so-called herd immuni­ty, saying to do so would be “unethical”.



Tedros Adhanom Ghebreyesus cautioned against calls in some countries to let Cov­id-19 run its course un­til enough people de­velop the immunity needed to naturally halt its spread.

“Herd immunity is a concept used for vacci­nation, in which a pop­ulation can be protected from a certain virus if a threshold of vaccination is reached,” he pointed out during a virtual press briefing.

For measles, for in­stance, it is estimated that if 95 per cent of the population is vaccinat­ed, the remaining five per cent will also be protected from the spread of the virus.



For polio, the immu­nity threshold is esti­mated at 80 per cent.

“Herd immunity is achieved by protecting people from a virus, not by exposing them to it,” Tedros said.

“Never in the history of public health has herd immunity been used as a strategy for re­sponding to an out­break, let alone a pan­demic,” he insisted.



Covid-19 has killed well over one million people and infected more than 37.5 million since it first surfaced in China late last year.

Relying on naturally obtaining herd immu­nity in such a situation would be “scientifically and ethically problem­atic”, Tedros said.

“Allowing a danger­ous virus that we don’t fully understand to run free is simply unethical. It’s not an option.”



He pointed to the lack of information on the development of im­munity to Covid-19, in­cluding how strong the immune response is and how long antibod­ies remain in the body.

Tedros pointed to some cases where peo­ple are believed to have been infected with the virus a second time.

A study on Tuesday (13) showed Covid-19 patients may experi­ence more severe symp­toms the second time they are infected. Re­search published in The Lancet Infectious Dis­eases journal charts the first confirmed case of Covid-19 reinfection in the US – the country worst hit by the pan­demic – and indicates that exposure to the vi­rus may not guarantee future immunity.

Tedros also stressed the many long-term health problems of in­fection, which research­ers are only just begin­ning to understand.

And he pointed out that it has been estimat­ed that less than 10 per cent of the population in most countries are believed to have con­tracted the disease.

“The vast majority of people in most coun­tries remain susceptible to this virus,” he said.

“Letting the virus cir­culate unchecked there­fore means allowing unnecessary infections, suffering and death.”

Overall, it is estimat­ed that 0.6 per cent of people who contract Covid-19 die from the disease, Maria Van Kerkhove, WHO’s tech­nical lead on the virus, told Monday’s briefing.

“That may not sound like a lot,” she acknowl­edged, stressing though that it “is a lot higher than (for) influenza”.

She also pointed out that “the infection fatal­ity ratio increases dra­matically with age.”

While the elderly and people with underlying health conditions are clearly most likely to fall seriously ill from Cov­id-19, Tedros stressed that they were not the only ones at risk.

“People of all ages have died,” he said.