Analysis
A misleading numerical comparison is circulating to suggest that polio vaccination is substantially more dangerous than contracting polio. Posts claim that the probability of a child dying from polio is approximately “one in a trillion,” while presenting the probability of death following vaccination as approximately “one in 215,000.” The calculation is frequently shared in screenshots or simple graphics, giving it the appearance of an independent statistical assessment.
The comparison combines measures that cannot validly be placed side by side. It estimates the risk from polio using the current number of cases in highly vaccinated populations, without accounting for the protection created by vaccination or the risk that would return if immunity declined. At the same time, it treats health events reported after vaccination as confirmed deaths caused by the vaccine, without evidence of causality.
Current disease incidence, historical infection risk, reports of events following vaccination and vaccine-attributable deaths are therefore presented as though they were equivalent measures. The apparently precise figures make the narrative more persuasive than an overt conspiracy theory because audiences may believe they are independently evaluating the evidence.
The claim could be particularly harmful in endemic and outbreak-affected countries, where parents may already question why children require repeated doses or why vaccination continues when few cases are visible. It may also be adapted to other vaccines or translated into local languages, allowing the same misleading calculation to spread across different immunisation contexts.
Recommendations
Avoid repeating the false figures prominently in headlines, graphics or social media captions. Begin communications by explaining that vaccination is the reason polio has become rare in many countries, briefly clarify why the calculation compares incompatible information, and close by reinforcing the consequences of declining population immunity.
Develop a short carousel or animation explaining four questions audiences should ask when seeing vaccine-risk calculations: whether the populations are comparable, whether the same time period is being used, whether the figures represent events occurring after vaccination or events caused by vaccination, and whether low disease incidence is itself the result of vaccination.
Use paediatricians, epidemiologists and local health workers alongside polio survivors or rehabilitation specialists. In Pakistan, Afghanistan and outbreak settings, equip frontline workers and trusted community figures with a short response explaining why repeated vaccination remains necessary even when cases are not visible.