Few diseases affect all demographic groups equally. For example, the 1918–1919 influenza pandemic killed an unusually large number of young adults. Estimates are that half of deaths in the United States during that pandemic occurred among people aged 20 to 40. In recent flu seasons, the elderly have much higher mortality rates than do other age groups. For instance, during the 2018–2019 flu season, people 65 and older died at a rate more than 10 times greater than people 18 to 49 years old. The very young also have comparatively high mortality rates from the flu. In 2018–2019, children 0 to 4 years-old died at a rate six times higher than children 5 to 17 years-old.
When the Covid-19 virus began to spread widely in the United States in the spring of 2020, some epidemiologists expected that it would affect different demographic groups in about the same way that the flu does. In fact, though, while people 65 and older were particularly at risk, young children were less affected by Covid-19 than they are by the flu. The following chart prepared by the Centers for Disease Control and Prevention (CDC) displays for the United States data on Covid deaths by age group as of early November 2021.
The blue bars show the percentage of total deaths from Covid since the beginning of the pandemic represented by that age group and the gray bars show the percentage that group makes up of the total U.S. population. Therefore, an age group that has a gray bar longer than its blue bar was proportionally less affected by the virus and an age group that has a blue bar longer its gray bar was proportionally more affected by the virus. The chart shows that people over age 65 experienced particularly high mortality rates. Strikingly, people over age 85 accounted for nearly 30 percent of all deaths in the United States, while making up only 2 percent of the U.S. population.
The following chart displays data on Covid deaths by gender. Men account for about 49 percent of the U.S. population but have accounted for about 54 percent of Covid deaths.
Finally, the following chart displays data on Covid deaths by race or ethnicity. Hispanic, Black, and American Indian or Alaskan Native people have experienced proportionally higher Covid mortality rates than have Asian or white people.
What explains the disparity in mortality rates across demographic groups? With respect to age, we would expect older people to have weaker immune systems and therefore be more likely to die from any illness. In addition, early in the pandemic many older people in nursing homes died of Covid before it was widely understood that the disease spread through aerosols and that keeping people close together inside unmasked made it easy for the virus to spread. The very young have immature immune systems, which might have made them particularly susceptible to Covid, but for reasons not well understood, they turned not to be.
There continues to be debate over why men have experienced a higher mortality rate from Covid than have women. Vaccination rates among men are somewhat lower than among women, which may account for part of the difference. In an opinion column in the New York Times, Dr. Ezekiel Emanuel of the University of Pennsylvania noted that researchers at Yale University have observed “that there are well-established differences in immune responses to infections between men and women.” But why this pattern should be reflected in Covid deaths is unclear at this point.
Medical researchers and epidemiologists have also not arrived at a consensus in explaining differences in mortality rates across racial or ethnic groups. Groups with higher mortality rates have had lower vaccination, which explains some of the difference. Groups with higher mortality rates are also more likely to suffer from other conditions, such as hypertension, that have been identified as contributing factors in some Covid deaths. These groups are also less likely to have access to health care than are the groups with lower mortality rates. The CDC notes that: “Race and ethnicity are risk markers for other underlying conditions that affect health, including socioeconomic status, access to health care, and exposure to the virus related to occupation, e.g., frontline, essential, and critical infrastructure workers.”
Sources: Ezekiel J. Emanuel, “An Unsolved Mystery: Why Do More Men Die of Covid-19?” nytimes.com, November 2, 2021; Daniela Hernandez, “Covid-19 Vaccinations Proceed Slowly Among Older Latino, Black People,” wsj.com, March 2, 2021; Anushree Dave, “Half-Million Excess U.S. Deaths in 2020 Hit Minorities Worse,” bloomberg.com, October 4, 2021; Centers for Disease Control and Prevention, “Hospitalization and Death by Race/Ethnicity,” cdc.gov, September 9, 2021; Centers for Disease Control and Prevention, “Demographic Trends of COVID-19 cases and deaths in the US reported to CDC,” cdc.gov, November 5, 2021 Centers for Disease Control and Prevention, “2018–2019 Flu Season Burden Estimates,” cdc.gov; and Jeffery K. Taubenberger and David M. Morens, “1918 Influenza: the Mother of All Pandemics,” Emerging Infectious Diseases, Vol. 12, No. 1, January 2006, pp. 15-22.