Life-course vaccination can protect adults from infectious disease

Vaccines are an essential part of the care of babies and children, offering protection from diseases like diphtheria, tetanus, pneumonia, and polio, diseases that once harmed or killed thousands of U.S. children every year and that still kill thousands around the world. Sometimes forgotten is that adults can also benefit from vaccines. To prevent unnecessary deaths and improve public health, the U.S. and other countries need to take more seriously the concept of life-course vaccination, an approach to ensure that immunization programs are effectively implemented for people at all ages and stages of life.

In the 2017-2018 influenza season, only 37% of adults in the U.S. were vaccinated against the flu, a decrease of 6% from the previous season, even though the Centers for Disease Control and Prevention recommends vaccination as the best approach to avoiding infection. Influenza goes beyond aches and fever that can be treated with fluids and rest: Among the 49 million Americans who came down with the flu during the 2017-2018 season, as many as 959,000 required hospitalization and 79,400 died.

Vaccines can also prevent other diseases common among adults. The University of Washington’s Institute for Health Metrics and Evaluation estimates that in 2017 alone, lower respiratory infections (including pneumonia and influenza) led to more than 1.5 million deaths in those aged 50 and over globally, most notably in low-income countries, and accounted for 23 million years of life lost. Herpes zoster (the virus that causes shingles) causes few deaths, but it is a major cause of reduced productivity and affects independent daily living.

This ongoing burden of preventable disease flourishes in the absence of a comprehensive global policy on adult immunization. The World Health Organization took an important step by issuing a global influenza strategy, a strategy I hope will provide a pathway toward stronger country-to-country capacity to handle and detect disease, including emerging infections beyond influenza.

In addition to causing personal suffering, bypassing adult vaccination has economic consequences. In 2015, influenza, pneumonia, and shingles cost the U.S. more than $8.4 billion through expenses for treatment and lost productivity.

The problem of low vaccination rates among adults isn’t limited to the U.S. It’s a worldwide phenomenon. Less than half of countries publicly recommend that older adults be vaccinated against influenza, and influenza vaccination rates in adults over 65 in countries that are part of the Organization for Economic Cooperation and Development range from as low as 2.8 percent in Estonia to as high as 84 percent in Korea.

Middle- and low-income countries are even less likely to include adult vaccination than high-income countries. With limited resources and weaker health systems, these countries focus on other priorities. In addition, individuals don’t always see the value of vaccines or lack access to them.

Enter life-course vaccination. It is an embodiment of the simple fact that the risk of infectious disease continues long past childhood and into old age. Yet only a few countries, such as the United States, the United Kingdom, and Australia, have embraced life-course vaccination and many have held few if any conversations about it.

Common barriers to adult vaccination range from concerns about financing and competing health priorities to the lack of broad evidence and a coordinated global program to ensure that vaccines are delivered to adults. A forthcoming analysis of low- and middle-income countries from the International Vaccine Access Center, the organization I work with, shows that few of them have influenza or pneumonia vaccine programs for adults. Even clinicians and other health care professionals may be reluctant to recommend vaccines to adults, perhaps due to lack of incentives and concerns about cost, effectiveness, and safety.

Life-course vaccination is urgently needed, given the rapid growth in the number of older adults worldwide. The United Nations reports that the global over-60 population is set to more than double between 2017 and 2050, growing to more than 2 billion people. Among adults over age 70, vaccine-preventable lower-respiratory infections such as influenza and pneumococcal pneumonia were the fifth leading cause of death in 2017. And that may be an underestimate since global surveillance to measure the extent of vaccine-preventable deaths in adults is severely lacking.

As people live longer and stay in the workforce longer, the contribution of vaccines to sustaining productivity increases. In addition, many older adults outside the workforce care for grandchildren, enabling working-age parents to keep working.

Immunization programs that cover the life span create an infrastructure for responding effectively and quickly to emergencies, pandemics, and outbreaks. These programs also have another welcome byproduct: connecting people with the health care system makes it possible to diagnose and treat other health problems and lend advice about healthy lifestyles.

Despite the acknowledgment of the value of life-course immunization, many countries are slow to recommend and fund vaccines for adults even when policy recommendations exist. Many high-income countries and some middle-income countries recommend adult vaccination against pneumonia, for example, but coverage has been suboptimal.

The emphasis on childhood immunization over the last decade, although much needed, is somewhat out of focus given current demographic shifts. The technical community, including partners such as the WHO, infectious disease experts, economists, researchers, and the healthy aging community, has yet to present advice on life-course vaccination to countries that is either consistent or comprehensive. The lack of global recommendations for countries at different stages of development sends the message, no doubt unintentional, that adult vaccines lack importance. Even in low-resource settings, there is much work to be done to look at the evidence, establish platforms for delivery of both immunization and preventive health care, and plan for integration into other investments in the health system.

The world’s health leaders can no longer ignore this issue. Adopting adult immunization and life-course vaccination as a preventive measure must become a political priority and emerge front and center for global health policy makers who are now working on a new vision and strategy for vaccines and immunization for the decade ahead. Just as a global movement has led to global support and funding for childhood vaccination, a similar one is needed to create momentum for adult and life-course vaccination.

Recognition of these demographic shifts and the importance of preventing infectious diseases in older adults is growing. The International Council on Adult Immunization, composed of experts in the fields of healthy aging, infectious disease, economics, and social science, hosted at Johns Hopkins Bloomberg School of Public Health, is synthesizing available data on these trends and the medical, economic, and social consequences of adult vaccines. Based on this work, the group will call for global recommendations from the WHO and healthy aging organizations on the actions countries need to implement to integrate immunization planning into broader health strategies. These recommendations should aim to increase the adoption of vaccines for adults, especially in countries where older age groups already exceed the population of younger age groups and in the many countries where that is soon to happen.

The scope of this work must extend beyond influenza, pneumonia, and shingles to encompass potential vaccines against HIV, tuberculosis, malaria, Ebola, respiratory syncytial virus, and cytomegalovirus. Attention must also be paid to vaccines for infections that commonly occur in health care settings, such as Clostridium difficile and Staphylococcus.

The WHO has declared 2021 to 2030 to be a decade of healthy aging. Getting serious about life-course vaccination in countries around the world will help make that a reality. And with a growing adult population in most parts of the world, it is a necessity.

Lois Privor-Dumm is director of policy, advocacy, and communications for the International Vaccine Access Center at Johns Hopkins Bloomberg School of Public Health and author of a white paper on the need for life-course vaccination as part of a thought leadership series initiated by the International Federation of Pharmaceutical Manufacturers & Associations to advance global thinking on the future of immunization.