Why Vaccines Are Less Effective in Older People, What It Means for COVID-19

Vaccine developers use processes that bias vaccines toward young people with healthy immune systems

Vaccinologists have largely failed to focus on tailoring vaccines for those most as risk—older people with weaker immune systems.Gorodenkoff/Shutterstock

As the global spread of severe acute respiratory syndrome coronavirus (SARS-CoV-2)—the cause of COVID-19—continues, we learn more about the effects of this new virus.

For many respiratory pathogens, including influenza viruses and respiratory syncytial viruses, older adults experience the most severe forms of disease and the highest death rates. For example, for every 10,000 Americans between 18 and 49 years old, only 0.4 people die from the annual flu. That number increases to 5.9 people per 10,000 for those aged 65–74 years, and 47.5 people per 10,000 for those over 74 years old.