Age has been connected to symptom severity and mortality in COVID-19, however, it does not affect susceptibility to infection with the virus.
Age does not affect coronavirus disease 2019 (COVID-19) susceptibility, according to a recent study published in Scientific Reports.
The COVID-19 pandemic has caused over 1 million deaths and there have been more than 37.8 million confirmed cases worldwide, according to the World Health Organization. Elderly individuals have been found to have a higher mortality rate and develop more severe symptoms of COVID-19.
Investigators used data from Japan, Spain, and Italy to determine whether COVID-19 susceptibility and age were connected. Causes of mortality in elderly individuals may boil down to 2 factors, the first of which is age-dependent susceptibility, meaning elderly people are more likely to become infected due to advanced age.
The other factor is age-dependent severity, meaning that the elderly will develop a more severe form of the disease, which will be reflected in the mortality rate. These 2 factors are not fully understood for COVID-19, according to the study.
Investigators found that COVID-19 susceptibility was independent of age; however, severity and mortality are likely dependent on age. As of May 2020, the mortality rate (number of deaths per 100,000 people) was 507.2 for Spain, 382.3 for Italy, and 13.2 for Japan.
Despite this drastic disparity in mortality rates, the age distribution of mortality is similar between the countries, according to the study.
Additionally, investigators created a mathematical model to calculate susceptibility in each age group, factoring in human-to-human contact and levels of outside-home activity. The model found that age should not influence susceptibility but does negatively influence severity and mortality.
Age does not contribute to COVID-19 susceptibility [News Release] October 12, 2020; Hokkaido, Japan. https://www.eurekalert.org/pub_releases/2020-10/hu-adn101220.php. Accessed October 14, 2020.