What demographic groups were most likely to remain unvaccinated against COVID-19 through 2025?
Executive summary
Available reporting and studies through the provided sources show that vaccine hesitancy and lower COVID-19 vaccine uptake in the 2020s clustered by geography (notably parts of sub‑Saharan Africa), by political affiliation in the United States (Republican identifiers showed declining support for vaccine requirements), and by age/health status for vaccine recommendations — with older and immunocompromised people prioritized for additional doses while children under 2 continued to be a concern when unvaccinated [1] [2] [3] [4]. Sources do not provide a single, global list of “most likely to remain unvaccinated through 2025”; instead they document patterns (hesitancy ranges by country, shifting U.S. partisan attitudes, and groups singled out by health authorities) [1] [2] [3] [4].
1. Geography: pockets of persistent hesitancy, especially in parts of sub‑Saharan Africa
Academic scoping and synthesis work cited in the materials identifies vaccine hesitancy as a major hurdle in sub‑Saharan Africa, with reported hesitancy rates ranging from 14% in Ethiopia to as high as 65% in Tanzania — indicating that in some countries a sizeable share of the population remained reluctant or unvaccinated into the mid‑2020s [1]. Those studies link hesitancy to local demographics, cultural beliefs, access to accurate information and socioeconomic barriers rather than a single global cause [1]. Available sources do not quantify total unvaccinated populations worldwide through 2025, only these country‑level hesitancy ranges and contributing factors [1].
2. U.S. political and social divides tracked to lower uptake
Polling and analysis show that partisan attitudes shifted significantly after the pandemic’s first years: Republican support for school vaccine mandates fell from 79% in 2019 to 52% by 2025, while Democrats stayed steady — a political realignment that correlates with lower vaccination acceptance among some conservative communities and likely sustained pockets of unvaccinated people in the U.S. [2]. Reporting also notes a resurgence of vaccine‑preventable disease (measles) concentrated among the unvaccinated in 2025, which underscores that political and social fractures produced measurable public‑health consequences [2]. The sources document attitudes; they do not produce a definitive demographic count of unvaccinated Americans through 2025 [2].
3. Age and clinical risk groups: priority does not equal full uptake
Clinical guidance through 2025 emphasized older adults and immunocompromised people as groups to receive additional COVID doses because those doses reduced hospitalization and critical illness risk, but recommendations alone do not guarantee full uptake [3]. Pediatric guidance highlights that very young children (six months to two years) remain vulnerable when unvaccinated and were still being hospitalized and dying at higher rates among the unvaccinated in 2025, implying that some parents declined vaccination for their youngest children [4]. Sources describe who was recommended for vaccines and who was still at risk but do not give exact coverage percentages by age group for 2025 [3] [4].
4. Drivers behind remaining unvaccinated: access, beliefs, and information
The academic review and public‑opinion reporting converge on multi‑factorial causes: demographic attributes (age, gender, location), political views, safety concerns, cultural beliefs, socioeconomic barriers, and lack of accurate information — all are repeatedly cited as contributors to persistent hesitancy and lower uptake [1] [2]. The scoping review stresses heterogeneity across regions and study designs, signaling that local context determines which of these drivers dominate [1]. Sources do not authoritatively rank these drivers globally; they simply identify them and give country or subgroup examples [1] [2].
5. How experts and authorities framed the problem and solutions
Public‑health and clinical bodies continued to recommend updated vaccines for high‑risk groups in 2025–2026 and to emphasize timing and additional doses as ways to prevent hospitalizations and reduce severe outcomes; the Infectious Diseases Society of America, for example, recommended at least one 2025–2026 dose for immunocompromised patients and two doses for older adults in some guidance discussions [3]. Policymakers and clinicians framed the issue as one of both supply/access and demand/education, but the sources show changes in advisory processes and public debate that complicated consistent messaging [3] [5].
6. What the sources do not say — key limitations
The assembled sources do not provide a single, synthesized global count or a definitive demographic ranking of “most likely to remain unvaccinated through 2025.” They report country‑level hesitancy ranges (sub‑Saharan examples), partisan shifts and polling (U.S.), and clinical prioritization (age/immunocompromise) — but no source here supplies comprehensive coverage rates by every demographic through 2025 [1] [2] [3] [4]. Any claim beyond the documented patterns above is not found in current reporting.
Bottom line: available sources identify geography (certain sub‑Saharan countries), political affiliation (shifts among Republicans in the U.S.), and specific age/clinical groups (very young children, immunocompromised, older adults as priority groups) as central to understanding who remained under‑vaccinated, but they stop short of a single global ranking or full coverage counts through 2025 [1] [2] [3] [4].