Countries with established influenza vaccination programs reached significantly higher COVID-19 vaccine coverage than those without such systems, according to new research from the Partnership for International Vaccine Initiatives (PIVI) and the U.S. Centers for Disease Control and Prevention (CDC). PIVI told Charity Journal that routine immunization infrastructure proved critical in determining how quickly countries could scale pandemic response.
Routine vaccine systems shaped pandemic performance
The study, published in the peer-reviewed journal Vaccines, analyzed data from 60 low- and middle-income countries alongside field evaluations across 16 CDC-supported regions. Researchers found that countries with mature influenza vaccination programs achieved 46% COVID-19 vaccination coverage after one year, compared with 25% in countries without comparable systems.
The study also revealed timing gaps in rollout speed. One-quarter of countries with established flu vaccination programs began COVID-19 vaccinations by January 2021, compared with just 8% of countries without those systems. In upper-middle-income countries, some with influenza programs launched as early as December 2020, while none without such systems did.
Dr. Joseph Bresee, PIVI Director at the Task Force for Global Health, said the findings reinforce the role of foundational public health systems rather than disease-specific response planning.
“These findings underscore the role of mature seasonal health worker influenza vaccination programs in support of effective and timely vaccination during a pandemic,” he said. “They enable countries to implement vaccination programs more quickly and reach targeted populations faster.”
Earlier coverage by Charity Journal on global health infrastructure financing trends highlighted similar arguments from donors shifting toward systems-based investments rather than isolated program funding.
Infrastructure, not just vaccines, drove delivery speed
The research points to operational infrastructure as the key differentiator in pandemic performance. Countries with influenza vaccination programs were more likely to already maintain cold-chain equipment such as storage boxes in frontline health facilities, enabling faster vaccine distribution once COVID-19 doses became available.
These systems also supported flexible delivery models, including workplace vaccination sites and mobile clinics, which expanded reach beyond traditional health facilities. Researchers noted that influenza programs effectively created rehearsal systems for adult vaccination delivery, something many countries lacked before the pandemic.
The study also linked workforce familiarity with vaccination processes to higher uptake, noting that health workers with annual flu vaccination exposure were more likely to accept and deliver COVID-19 vaccines efficiently.
Dr. Bresee said these systems reflect broader preparedness benefits that extend beyond any single disease.
“Investing in foundational infrastructure such as vaccination delivery and surveillance systems ensures countries can respond effectively when new threats emerge,” he told Charity Journal in an interview.
The findings align with broader global health arguments, with donors increasingly prioritizing system resilience over vertical disease programs.
PIVI pushes shift toward integrated immunization systems
PIVI said the results strengthen its advocacy for long-term investment in integrated vaccination systems rather than disease-specific silos.
The organization emphasized that routine immunization programs for health workers build operational capacity, strengthen delivery systems, and create the logistical experience needed to respond during public health emergencies.
It also pointed to broader benefits of influenza vaccination programs, including reduced preventable illness among high-risk groups such as health workers, pregnant women, and people with chronic conditions. When integrated into national health systems, PIVI said, these programs become both sustainable and cost-effective.
The study’s release during World Immunization Week adds urgency to ongoing debates over global health financing, particularly in low- and middle-income countries where infrastructure gaps continue to shape vaccine equity outcomes.
PIVI said the findings support a long-term shift toward strengthening routine adult vaccination systems as a core component of pandemic preparedness planning.