--- description: Breaking news and analysis from time.com. Politics, world news, photos, video, tech reviews, health, science, and entertainment news. title: Infectious diseases often disproportionately impact older adults. But why? image: https://static.time.com/v3/assets/bltea6093859af6183b/blte152d590109540bd/6a4b523139362b80b0841596/shutterstock_1868898253.jpg?branch=production&width=3840&quality=75&auto=webp&crop=16:9 --- # Infectious diseases often disproportionately impact older adults. But why?  While advances in science have enabled people to live longer lives, those extra years are not always quality ones. As bodies age, they become more vulnerable to disease, including infectious disease. This is evident not only when looking at hospitalization and death rates from the recent COVID-19 pandemic but also considering the severity of symptoms that occur with other infection conditions such as influenza (flu), respiratory syncytial virus (RSV), and shingles. That is why it is important for older individuals to take steps to stay healthy and ward off illness. Why are we more at risk of illness the longer we live? Simply put, our immune systems age as we age, becoming less efficient. “The technical term is immunosenescence, which means that the immune system, as we age, gets a little bit weaker and is not necessarily able to respond to infection in the same way,” says Alejandra Gurtman, Senior Vice President of Vaccine Research and Development at Pfizer. Immunosenescence actually begins as early as the mid-20s and progresses gradually: The older a person is, the more likely they are to contract bacterial and viral infections. Older individuals are also more likely to have comorbidities, including obesity, diabetes and chronic obstructive pulmonary disease (COPD), which can greatly impact overall health. When coupled with immunosenescence, the aging population faces an increased risk of serious symptoms following contraction of an infectious disease. “RSV is a good example of an infectious condition that often disproportionately affects older adults,” Gurtman says. “In older individuals, RSV can result in serious illness, hospitalization, or even death, so there is a significant need to protect this at-risk population. In the United States alone, RSV infections account for approximately 60,000-160,000 hospitalizations and 6,000-13,000 deaths each year in adults 65 years and older.” “ > The technical term is immunosenescence, which means that the immune system, as we age, gets a little bit weaker and is not necessarily able to respond to infection in the same way” Alejandra Gurtman — Senior Vice President of Vaccine Research and Development at Pfizer  In addition to the physical burden, the financial fallout from illness in older adults is sobering. In 2019, people over age 55 accounted for 30% of the U.S. population, yet they were responsible for 56% of total spending on health care. By 2050, it’s estimated that the number of people over 65 will be twice what it is now, and the 80-and-over population will triple. This is expected to cause a significant economic burden on individuals, families, health care systems, and the government due to more serious illnesses, additional medical complications, and longer hospital stays. How much can we do to prevent these outcomes as we age? In addition to practicing healthy habits, such as exercising, eating a nutritious diet, getting sufficient sleep, and avoiding smoking, older people can take advantage of potentially life-saving vaccines. Pfizer has worked for decades to develop a vaccine against RSV, and on May 31, 2023, the U.S. Food and Drug Administration (FDA) approved the company’s RSV vaccine for the prevention of lower respiratory tract disease caused by RSV in individuals 60 years and older. The vaccine, RSVpreF, contains stabilized RSV prefusion F proteins. The F protein exists in two forms, prefusion and postfusion – only the prefusion form on the virus can bind to human airway cells, resulting in the virus entering the cells where it can replicate causing illness. Studies by the National Institute of Health found the prefusion F structure and identified that F protein constrained in this prefusion form is more immunogenic compared to the postfusion form. This advance broke a deadlock of over 50 years of RSV vaccine development, providing a potential path forward for vaccine development. Pfizer built upon this observation to make a vaccine comprised of two stabilized prefusion F proteins, one from RSV A and one from RSV B strains. Top-line data from the Phase 3 clinical trial evaluating RSVpreF in adults 60 years of age and older showed that in participants with more severe disease, RSVpreF was 85.7% efficacious against RSV-associated lower respiratory tract illness (LRTI) with at least 3 symptoms. When looking at RSV-associated LRTI defined by at least 2 symptoms, there were 11 cases in the vaccine group and 33 in the placebo group with an observed efficacy of 66.7%. The company is also investigating RSVpreF as a maternal vaccine to help protect against the complications of RSV disease in infants from birth through six months of age. Gurtman says the PDUFA date for maternal immunization is expected by the end of August 2023.    In collaboration with BioNTech, Pfizer worked quickly during the early stages of the COVID-19 pandemic to develop a groundbreaking vaccine using mRNA technology. “We are continuing to invest in research surrounding our mRNA COVID-19 vaccine, including advancing strategies to address emerging variants,” Gurtman notes. In addition, Pfizer is developing a novel modRNA flu vaccine candidate, which is currently being evaluated in a Phase 3 study in two age groups – 18-64 and 65+. For a company that has multiple infectious disease vaccines in development, combination vaccines are a next logical step. Combination approaches, if successful, have the potential to help alleviate the impact of multiple diseases, while simplifying immunization practices for health care providers as well as individuals, potentially leading to better uptake. Gurtman says, “Evidence has shown that convenience is important for people in staying up to date on their immunizations. Therefore, Pfizer is researching combined vaccine strategies against COVID and flu and RSV and flu.” Developing potentially life-saving vaccines is not without its challenges. “Clearly, vaccine development is complicated and can take time,” Gurtman states. “But at Pfizer, we have a long legacy in vaccine research and development and are committed to continued innovation. Our goal is to help prevent some of the most challenging viral and bacterial infections, enabling people to live longer, healthier lives, and I am immensely proud to work alongside an amazing team of scientists who are helping achieve that goal.” [](https://www.pfizer.com/science/focus-areas/vaccines?cid=prt%5Fcorp%5Fclntr%5Fage-related-illness%5F0523&ttype=prt) Breakthroughs that Change Patients’ Lives [Find Out More](https://www.pfizer.com/science/focus-areas/vaccines?cid=prt%5Fcorp%5Fclntr%5Fage-related-illness%5F0523&ttype=prt) Infectious diseases often disproportionately impact older adults. 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