Herd immunity

Herd immunity built without the vaccine is a lethal path.

Australian epidemiologist Gideon Meyerowitz-Katz said: We cannot build herd resistance to COVID-19 by natural infection. It is a strategy that will involve many victims. Releasing the lockdown measures too early is not the way we should go.

Gideon Meyerowitz-Katz shares his thoughts in ‘The Guardian’ on how to achieve the so-called herd immunity during the COVID-19 pandemic. The scientist, who also deals with the problems of chronic diseases at the University of Wollongong, strongly opposes the strategy according to which we would achieve a level of herd immunity by releasing or partial releasing the rigors of physical distance and exiting the lockdown.

He believes that the fight against coronavirus by building herd immunity in the name of saving the economy means sacrificing the lives of many vulnerable people.

Herd immunity is gained in two ways. One can mean the death of many people.

Herd immunity means a situation when there are enough people in the population who are resistant to a given infectious disease, so there is no further transmission or further infection, thanks to which a vulnerable part of the population is protected from falling ill. It is related to the concept of “herd immunity threshold”, which is the moment from which we can say that the risk of getting sick is minimal. This immunity threshold is obtained in two ways, as a result of natural illness and/or mass vaccination. The herd immunity threshold is different for each infectious disease. After exceeding it, the disease withdraws, and people who for some reasons cannot be vaccinated (e.g. are too young or suffer from diseases that reduce immunity) are safe. There is no one else to infect them with.

Vaccination is the surest way to gain herd immunity. The second way to build mass immunity is through illness and survival. This is a dangerous path and involves victims, which in the case of many underlying diseases means fatalities, says the epidemiologist. When we think about COVID-19, we must realize that it would be a strategy that would cost the lives of so many people.

COVID-19: three to six infected people per 1,000 patients die

Preliminary estimates show, according to Gideon Meyerowitz-Katz , that the herd immunity threshold for COVID-19 is 60-70 percent (with 85 percent calculations also available), which means that this percentage of society would have to be infected with the new coronavirus. It also cannot be assumed that only young and generally healthy people would become infected and thus we will achieve the desired immunity threshold without much sacrifice. This is impossible, both from the point of view of the functioning of society and the way infectious diseases spread. Usually, the so-called clusters (accumulation of cases of the disease in a specific area and over a certain period) with low immunity appear, where the disease is still spreading, despite our efforts.

If more people fall ill at the same time, hospitals will simply not be able to provide them with proper care. There will be a situation in which it is necessary to refuse admission to the hospital of people over 80 years of age, and even younger, but with comorbidities. This will immediately increase the number of COVID-19 fatalities before the herd immunity threshold is reached.

Meyerowitz-Katz also reminds that death due to coronavirus is not the only harvest of COVID-19. We still do not know much about the health effects of the disease, and about the far-reaching health consequences.