For the first time in history, adults over 65 outnumber children under five. By 2030, nearly 1 billion people will be in this age group. Yet while childhood immunization has saved millions of lives, adult vaccination remains neglected, especially in low- and middle-income countries.
A new World Health Organization (WHO) study, published in Vaccines, highlights the urgent need to expand adult immunization. Doing so could promote healthy aging, reduce healthcare costs, and combat antimicrobial resistance.
Inequitable Access Leaves Millions Unprotected
WHO recommends vaccines for adults against influenza, COVID-19, pneumococcal disease, tetanus, and RSV. However, many low- and middle-income countries still exclude these from national schedules, leaving millions vulnerable.
“With outbreaks of preventable diseases rising, people need every recommended vaccine—at every life stage,” said Dr. Alba Vilajeliu, lead author and WHO immunization expert. “This isn’t just about survival—it’s about quality of life, productivity, and easing pressure on health systems.”
Under Immunization Agenda 2030, countries aim to ensure lifelong vaccine access. Strengthening adult immunization could also boost healthcare infrastructure, workforce skills, and public trust in vaccines.
COVID-19 Proves Adult Vaccination Can Scale—But Other Vaccines Lag
The pandemic pushed adult vaccination into the spotlight. By 2023, 89% of health workers and 84% of older adults had received COVID-19 shots. Yet this success hasn’t extended to other critical vaccines.
For example:
Seasonal flu causes 3-5 million severe cases and up to 650,000 deaths yearly, yet only 4% of low-income countries vaccinate pregnant women, and 8% protect older adults.
In contrast, 87-89% of high-income countries include flu shots in their programs.
Tetanus vaccines for pregnant women show progress—73% of low-income and 80% of lower-middle-income countries now offer them. These efforts could pave the way for new maternal vaccines, like RSV shots for infants or future malaria and Group B strep vaccines.
Vaccines Offer Huge Economic Returns
A 2023 Office of Health Economics (OHE) report found that scaling up adult vaccines for flu, RSV, shingles, and pneumococcal disease in just 10 high-income nations returned up to 19 times the initial investment—worth $4,637 per full vaccination course. The returns could be even greater in lower-income countries.
New Vaccines and Technologies Expand Possibilities
Beyond scaling existing shots, next-generation vaccines—like TB and combo respiratory virus vaccines—are being developed for adults. Advances like mRNA technology are speeding up safe, effective vaccine production.
To succeed, countries must:
- Strengthen primary healthcare systems for adult immunization.
- Train health workers to promote lifelong vaccination.
- Engage community leaders to build trust and demand.
“Now is the time to build a strong foundation,” said Dr. Kate O’Brien, WHO’s immunization director. “Prevention must be prioritized—shifting from treating disease to sustaining lifelong health. Adult vaccination is critical to that change.”
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