The extremely young, the old, and the unwell are the most common victims of the flu. According to popular myth, what set the 1918 pandemic apart was the fact that it killed healthy young adults at the same rate as older persons and those with preexisting diseases.
Good health and youth were found to offer no protection against the virus, which killed at least 50 million individuals worldwide (or 1.3% of the global population) at the time. Covid, on the other hand, only accounted for 0.09 percent of fatalities.
However, an article published in PNAS on Monday casts doubt on that widely held belief. Researchers concluded that those with chronic disorders or nutritional deficits were more than twice as likely to die as those without such problems, regardless of age, based on evidence in bones of people who died in the 1918 pandemic.
Although the 1918 flu virus did claim the lives of many young people, the research argues that it is not an exception to the rule that the elderly and the sick are more susceptible to the effects of infectious illnesses.
University of Colorado at Boulder anthropologist and article co-author Sharon DeWitte drew a clear conclusion from the findings: “We should never expect any nonaccidental cause of death to be indiscriminate.”
University of Michigan historian of the flu pandemic J. Alex Navarro called the skeletal research “a fascinating paper and a very interesting approach to studying this issue.”
Amanda Wissler, the paper’s primary author and an anthropologist at Ontario’s McMaster University, was interested by reports that the 1918 flu virus killed young and healthy individuals just as frequently as persons with preexisting problems. Back then, TB was common among young people and there were no immunisations or medications to protect children from illness.
The mystery surrounding the victims of that illness, however, led many to believe that being well was no defence. The death curve caused by the flu has an odd W shape. Death rates often peak in early infancy and later in life, reflecting the vulnerability of infants and the elderly, respectively.
Death rates skyrocketed in 1918, especially among those aged 20 to 40, but also among infants and the elderly. Numerous accounts from the time suggested that this held true regardless of whether or not the young adult was in good health.
Having studied the Black Death in a similar manner, Drs. Wissler and DeWitte hypothesised that they might test the theory using a sample of young individuals. Tiny bumps appear on people’s shin bones as a result of chronic stress caused by conditions including TB, cancer, or a lack of nutrients.
According to Peter Palese, a specialist in the flu at the Icahn School of Medicine at Mount Sinai, looking for those bumps “is quite legitimate” as a technique of assessing frailty.
The skeletons were sourced from the Cleveland Museum of Natural History. The names, ages, and dates of death for its collection of 3,000 sets of remains stored in big drawers in a huge room.
The researchers also looked at the skeletons of 288 persons who had died before the outbreak.
The findings were unmistakable: both young adults and the elderly with brittle bones were especially susceptible to infection. Many healthy people also perished, but the chances of death were substantially higher for those who were already chronically sick.
Dr. Arnold Monto, an epidemiologist and emeritus professor at the University of Michigan’s School of Public Health, found that explanation plausible.
According to Dr. Monto, “we are not used to the fact that younger healthy adults are going to die,” which was a common occurrence during the 1918 epidemic.
Dr. Palese claimed that the W-shaped death curve seen during the 1918 pandemic could be explained. He interpreted this to suggest that most persons over the age of 30 or 40 had been exposed to a comparable virus, which had conferred some immunity. Adults under the age of 30 were protected.