Adult immunization as a smart investment

An aging population compounded by the threat of vaccine-preventable diseases and their link to chronic diseases are compelling reasons to maximize efforts to vaccinate the adult population.

Speaking during the Health Connect media forum, the Adult Immunization Committee of the Philippine Society for Microbiology and Infectious Diseases (PSMID) co-chair Dr. Faith Villanueva revealed that adults comprise nearly 70% of the country’s total population, a large proportion of whom are in the workforce, providing for their families and essentially driving the economy.

However, Dr. Villanueva explained, the protection provided by childhood and adolescent vaccines and natural immunity derived from getting sick with infections weaken with age, making adults susceptible to various infectious diseases, including vaccine-preventable diseases. She noted that the link between infectious diseases and chronic diseases is well-established.

Individuals with chronic diseases such as diabetes, heart and lung conditions, chronic kidney failure, and other chronic conditions that weaken the immune system are at increased risk for infectious diseases. The misuse and overuse of antibiotics have also contributed to the problem of antimicrobial resistance in the country, she added.

Of the top 11 leading causes of sickness and death in the country in 2021 and 2022, four are infectious diseases, namely pneumonia, chronic lower respiratory diseases, pulmonary tuberculosis, and COVID-19, citing data from the Philippine Statistics Authority (PSA). She also pointed out that the top causes of death in the country — ischemic heart diseases, cancers, cerebrovascular diseases, and hypertensive diseases — are almost always associated with infections.

A new study by the UK-based Office of Health Economics (OHE) shows that investing in adult immunization can pay huge dividends in terms of health and socioeconomic benefits.

Commissioned by the International Federation of Pharmaceutical Manufacturers & Associations (IFPMA), the study reviewed published evidence on the burden of influenza, pneumococcal disease, herpes zoster, and respiratory syncytial virus (RSV) in adults, the health, and healthcare systems of Australia, Brazil, France, Germany, Italy, Japan, Poland, South Africa, Thailand, and the United States. It then utilized health economic modelling to estimate the benefit-cost ratios and net monetary benefits associated with adult immunization programs in the 10 countries.

The study found that adult vaccines against the four aforementioned infectious diseases can return up to 19 times their initial investment to society, when their significant benefits beyond the healthcare system are monetized. This is the equivalent of billions of dollars in net monetary benefits to society, or more concretely, up to $4,637 (P265,378) for one individual’s full vaccination course. The study pointed out that these results are based on mostly conservative estimation methods and inputs are proportionate with returns observed in childhood immunization programs, which are widely recognized as some of the most cost-effective interventions available to healthcare systems.

The study also uncovered significant evidence for the value of adult immunization across the three overarching domains of vaccine value. In terms of value for population health, evidence shows that adult immunization is highly effective in preventing diseases, their sequelae (complications or aftereffects), and mortality, particularly in older adults and those with chronic health conditions.

In terms of value for healthcare systems, the study found that adult immunization programs are highly cost-effective and can result in net cost savings for healthcare systems. It noted that recent studies have highlighted that these programs not only offer health benefits but also yield financial gains by averting hospital inpatient and emergency care.

In terms of value for society, the study found that expanding adult immunization programs and coverage can lead to substantial productivity gains by individuals and their caregivers and economic benefits for society. Additionally, adult immunization programs can contribute to health and economic equity within countries, particularly benefiting vulnerable populations and underserved communities.

The study also showed that many broader elements, for example societal-economic elements such as productivity value, are currently underrepresented in academic literature.

The study made three key recommendations. First, adopt a prevention-first mindset and provide robust funding for adult vaccination programs. It urged healthcare systems to invest in strategies to cope with unprecedented and growing demand. Prevention must be at the heart of such strategies, and robust adult immunization programs are a fundamental component of effective prevention, the study stated.

Second, implement and optimize adult immunization programs as part of a life course immunization approach to address the projected rise in the burden of vaccine-preventable diseases. The study stressed that expanding access to a broader adult population can generate more value and higher net cost savings for healthcare systems and society. Adult immunization programs also present a great opportunity to help our societies age well and sustainably long into the future — and deliver an excellent return on investment in the process.

Third, expand and develop the evidence base for the value of adult immunization programs to address significant gaps in evidence regarding the broader elements of the value of these programs. Further research is needed to close these knowledge gaps, particularly in middle- and lower-income countries. Doing so is vital for informed decision-making and targeted policy interventions that aim to optimize the value of adult immunization programs.

 

Teodoro B. Padilla is the executive director of Pharmaceutical and Healthcare Association of the Philippines (PHAP). PHAP represents the biopharmaceutical medicines and vaccines industry in the country. Its members are in the forefront of research and development efforts for COVID-19 and other diseases that affect Filipinos.

Adult immunization as a smart investment
Philippines Pandemic