Israeli health expert: COVID R-rate is overused, abused and misunderstood

“We have been obsessed with R, as if we know exactly what is happening with infection. But it is an illusion," said leading Hebrew University epidemiologist Prof. Hagai Levine.

 Meuhedet Health care worker wearing protective gear takes swab samples from a woman, at Meuhedet coronavirus testing center in Jerusalem, January 6, 2022.  (photo credit: YONATAN SINDEL/FLASH90)
Meuhedet Health care worker wearing protective gear takes swab samples from a woman, at Meuhedet coronavirus testing center in Jerusalem, January 6, 2022.
(photo credit: YONATAN SINDEL/FLASH90)

People around the world who previously did not know the difference between viruses and bacteria have been introduced, thanks to the COVID-19 pandemic, to a whole new medical vocabulary – from variants, incubation and asymptomatic to mRNA, social distancing, ECMO and infection-acquired immunity.

A term that we constantly hear is the R-rate, claimed to measure whether the coronavirus is receding or expanding, as if it were a thermometer determining fever. Standing for “reproduction,” it has now risen over 1.0, sending shivers down the spines of “experts” on TV and beyond.

But according to Prof. Hagai Levine, a leading epidemiologist at the Hebrew University-Hadassah Braun School of Public Health and Community Medicine and chairman of the Association of Public Health Physicians, R is overused, abused and misunderstood.

First used almost a century ago in demography, R originally measured the reproduction of people – whether a population was growing or not. In epidemiology, the same principle applies, but it measures the spread of infection in a population.

If R is two, one infected person will infect, on average, two others, who will infect four others, who will infect eight others, and so on. The measure makes it possible to work out the extent of the spread – but not the speed at which the infection grows.

 Technicians carry out a diagnostic test for Covid-19 in a lab at Leumit Health Care Services branch in Or Yehuda, on January 21, 2022.  (credit: YOSSI ZELIGER/FLASH90) Technicians carry out a diagnostic test for Covid-19 in a lab at Leumit Health Care Services branch in Or Yehuda, on January 21, 2022. (credit: YOSSI ZELIGER/FLASH90)

“We have been obsessed with R, as if we know exactly what is happening with infection. But it is an illusion,” Levine explained in an interview on Monday. “The term represents the spread of disease but does not help overcome it. It doesn’t address the main problem of severe illness, hospitalization and death.”

“Infection also involves new variants, how protected people are, specific populations at higher risk and crowding,” he said. “A six-year-old child who was infected is not the same as a 75-year-old man. R is a technical matter, and things can change very rapidly. It’s only one tool among sets of indicators.

“The main challenge is to change the behavior of people. Don’t be obsessed with R; focus on prevention and long-term public health.”

THE R value of a disease applies only when everyone in a population is completely vulnerable to it, no one has been vaccinated, no one has had the disease before, and there is no way to control its spread. This is not relevant to the current pandemic.

R only represents an average across a region that can miss regional clusters of infection. Most experts say the R-rate is kept artificially high by the vast numbers of infections and deaths in geriatric facilities and does not reliably represent the risk to the general population.

Constant publication of the R seems to have become an unhealthy political and media fixation, Levine said. R is an imprecise estimate based on assumptions and does not reflect the current status of an epidemic, and it can rise and fall when case numbers are low, he said.

It is also an average for a population and therefore can hide local variations. Levine stressed that R could hide the importance of trends in the number of new infections, deaths and hospital admissions, and cohort surveys to see how many people in a specific group currently have the disease or have already had it.

Many people never infect others, but a few so-called “super-spreaders” transmit the disease more than the average, maybe because they attend crowded, indoor events where the virus spreads more easily, he said. As few as 10% to 20% of infected people seem to cause 80% of new COVID-19 cases, so bans on certain crowded indoor activities could have more benefit than universal restrictions introduced whenever the R value hits one, he added.

“I am worried now that there are populations and places where COVID-19 vaccination is low,” Levine said. “It is not a matter of haredim [ultra-Orthodox] and Arabs but of people living in lower socioeconomic conditions, who have less access to vaccination centers and public health information and less trust in the establishment.”

 

WHEN ASKED whether the Bnei Brak funeral of 94-year-old Rabbi Chaim Kanievsky may raise the R-rate even more, Levine said since the estimated 500,000 who attended were outdoors, the risk was likely low. But most arrived by buses, and if one person who was sick with COVID-19 coughed, he could easily have infected his fellow passengers.

“There is too much public relations and not enough public health,” the Public Health Physicians Association chairman said. “Many bureaucrats in the Treasury’s budget division have come to regard public health as a nuisance rather than as a long-term investment.”

Levine said he was “not worried that the R of coronavirus is over 1, because it doesn’t reflect the real picture. I am worried about polio because not enough children have been taken by their parents to be vaccinated. We need to work together with local populations and make the healthy choice as the easy choice.”

“There are not enough public health nurses and academics, as the field is less prestigious,” he said. “They are much older than hospital and health fund nurses. Public health nurses in Tipat Halav [well-baby] centers should not earn less than those in health fund clinics. The Central Bureau of Statistics census that has been launched is very important in understanding the big picture and providing current data.”

All local authorities, especially weaker ones, should have permanent public health professionals, as there are in Scandinavia and other places, the epidemiologist said.

“They are needed to change behavior – to educate against smoking, eating junk food, going to work when you’re sick and encouraging people to exercise and maintain proper weight,” he said.

After almost two and a half years of living in a pandemic, Israelis are tired of it all, Levine said.

“But scaring people doesn’t work,” he said. “You have to make vaccination centers accessible at hours that are convenient to them and eliminate the struggle of getting tested and obtaining results quickly. Before Passover, people can be given free test kits to find out if they are infected before meeting family at the Seder.”

“We are not near the end of the pandemic or other major problems, such as other infectious diseases, climate change and earthquakes,” Levine said in conclusion. “Israel needs communal resilience.”