Are old diseases coming back from antivaxxers

1. What claim do people make — “Old diseases are coming back because of antivaxxers”?

The core claim is that the anti‑vaccine movement has caused formerly rare childhood diseases to resurface. Multiple analyses assert that measles, mumps, pertussis and varicella have resurged in the U.S. and elsewhere, with outbreaks explicitly tied to unvaccinated populations and clusters of vaccine refusal ^{[1] [4] [5]}. U.S. Centers for Disease Control case counts in 2025 document large increases in measles — over 1,600 cases and dozens of outbreaks — and attribute most cases to unvaccinated individuals and outbreak clusters, indicating transmission is concentrated where vaccination coverage has fallen ^{[2] [6]}. Historical context shows vaccine skepticism is not new, but contemporary networks and misinformation amplify reach ^[3].

2. Recent surveillance data shows tangible resurgence in measles and outbreaks this year

Federal surveillance through November 4, 2025, recorded 1,681 confirmed measles cases and 44 outbreaks in the U.S., a sharp rise from recent years, with 87% of cases associated with outbreaks and a substantial share occurring in unvaccinated people. Declines in kindergarten vaccination coverage from 95.2% in 2019–20 to 92.7% in 2023–24 correlate with the spread, demonstrating how even small drops below herd‑immunity thresholds permit outbreaks to seed and expand ^[2]. Earlier reports and reporting from 2023–2024 also show localized resurgences; those patterns cohere with the 2025 data and indicate a trend rather than isolated blips ^{[5] [2]}.

3. Why experts link outbreaks to vaccine hesitancy and access — evidence and limits

Analyses tie outbreaks chiefly to vaccine refusal and under‑vaccinated pockets, noting that the majority of cases are in unvaccinated or undervaccinated individuals and communities ^{[1] [6]}. The anti‑vaccine movement’s influence is framed as eroding public confidence and policy, contributing to reduced uptake. However, the data also point to mixed drivers: complacency after decades of low disease, variable state policies on mandates and exemptions, and access barriers can all reduce coverage. Historical and sociological studies show anti‑vaccine activism predates modern social media; contemporary networks, though, have accelerated message spread and politicized vaccination debates ^[3].

4. Global picture: not just a U.S. story — polio and international trends matter

Beyond measles in the U.S., public analyses warn of polio increases in countries like Pakistan and flag global complacency risks that could enable re‑emergence where immunization weakens. The anti‑vax movement and geopolitical disruptions have interfered with eradication efforts, and rising hesitancy in affluent countries can undermine global herd protection by enabling importations and local transmission ^[7]. International surveillance and outbreak responses remain essential because pockets of low coverage anywhere can seed wider spread; the U.S. 2025 measles outbreaks and overseas polio cases together illustrate the interconnected nature of vaccine‑preventable disease control ^{[2] [7]}.

5. Alternative explanations and where attribution becomes uncertain — separating correlation from sole causation

While analyses commonly attribute resurgence to vaccine hesitancy, some pieces note that attribution is multifactorial: declines in coverage, policy changes on school entry, access inequities, and waning immunity for certain vaccines all contribute. Outbreak investigations frequently identify unvaccinated clusters as amplification points, but national declines in coverage are uneven and not wholly explained by organized anti‑vax activism alone ^{[4] [3]}. Media framing can overemphasize the “antivaxxer” label as a single cause; credible surveillance stresses combined effects and the role of public health funding and outreach failures in sustaining protective coverage ^{[2] [3]}.

6. What’s missing from public discussion and what this means for policy and public health

Analyses emphasize the need to address not only misinformation but structural factors: restore high vaccination coverage through policy, school‑entry enforcement, targeted outreach in undervaccinated communities, and global eradication efforts. Data through 2024–2025 show that modest declines in coverage produced measurable public‑health consequences; reversing trends requires surveillance, communication, and access improvements. Recognizing the anti‑vaccine movement’s role is important, but effective responses must combine counter‑misinformation with practical measures to increase uptake and close coverage gaps identified in the surveillance reports ^{[2] [3]}.