One in Three Adults "Hesitant About Vaccines"... TikTok and YouTube Algorithms Fuel "Vaccine Distrust"

Up to 35% of Adults in 149 Countries Hesitate to Get Vaccinated
Anti-vaccine Posts Shared 3.7 Times More Than Pro-vaccine Content

As trust in vaccines weakens worldwide, it has been found that in some countries, more than one in three adults are hesitant about vaccination. Analysts say that distrust in vaccines and the spread of online misinformation are leading to decreased vaccination rates, which in turn is contributing to the resurgence of vaccine-preventable diseases such as measles.

Recently, a team of Indonesian researchers published a paper in the international journal 'Reviews in Medical Virology,' stating that declining vaccine confidence and the spread of misinformation are resulting in lower vaccination rates and a resurgence of diseases that can be prevented by vaccines.

A citizen is receiving a vaccine at Bumin Hospital in Gangseo-gu, Seoul. The photo is not related to a specific part of the article.

The research team conducted a comprehensive analysis of papers published in academic databases such as PubMed, Scopus, and Cochrane from 2000 to 2024, as well as materials from international organizations including the World Health Organization (WHO), UNICEF, and the Global Alliance for Vaccines and Immunization (GAVI).

The researchers focused on terms such as 'vaccine hesitancy,' 'vaccine confidence,' 'misinformation,' and 'vaccine policy,' selecting relevant studies and reports to investigate changes in vaccination rates, the factors that determine whether people get vaccinated, and the patterns of disease outbreaks following declines in vaccination rates.

The analysis found that the DTP (Diphtheria, Tetanus, and Pertussis) third-dose vaccination rate—a key indicator for immunization—fell globally from 86% in 2019 to 81% in 2021. In 2023, it partially recovered to 84%.

Vaccination Rates Drop... Measles Cases Rise

The decline in vaccination rates has actually led to an increase in infectious diseases. In particular, measles, which is highly contagious, can spread rapidly even with a slight drop in herd immunity levels. This makes it a prime example of how reduced vaccine uptake can influence outbreaks.

According to WHO data, the first-dose measles vaccine (MCV1) coverage in Europe dropped from 95% in 2019 to 92% in 2022. In 2021, approximately 9 million measles cases were reported globally, with 128,000 deaths—a level of severity not seen since 2006.

Even in the United States, which declared measles eliminated in 2000, new cases have reemerged. In 2024, a total of 285 confirmed cases were reported, fueled by low community vaccination rates.

The research team identified 'vaccine hesitancy' as one of the main factors behind these trends. This term refers to delaying or refusing vaccination even when vaccines are available.

The researchers noted, "In a survey of 149 countries, between 10% and 35% of adults in these nations were hesitant about vaccination," adding, "This is a global phenomenon not limited to any particular vaccine or region."

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Anti-Vaccine Information Spreads Faster Than Fact-Checks

The spread of misinformation via social networking services (SNS) was also identified as a key factor undermining vaccine confidence. The research team pointed out that recommendation algorithms on platforms such as Facebook, YouTube, and TikTok can lead users increasingly toward extreme anti-vaccine content—what they referred to as the 'rabbit hole' effect.

Anti-vaccine content was found to spread faster and more widely than factual vaccine information. The researchers explained, "Online, anti-vaccine posts are shared 3.7 times more than pro-vaccine posts, and analysis of X (formerly Twitter) data showed that during major vaccine rollouts, misinformation about vaccines reached its peak influence six hours before proper fact-checks appeared."

The researchers concluded that advances in vaccine technology alone are not sufficient to solve the problem of declining vaccination rates. They stressed the importance of maintaining a stable immunization infrastructure while simultaneously boosting public trust in vaccines and enabling rapid responses to misinformation.

The research team emphasized, "To sustain and expand global immunization achievements in the future, not only should vaccine technology advance, but public confidence and the resilience of healthcare systems must improve as well. In particular, boosting trust in vaccines should be seen as a core component of immunization success, and this will be crucial for protecting global health security over the next decade."

This content was produced with the assistance of AI translation services.