Doctors around the world are witnessing a spike in the number of measles cases, despite widespread access to an effective vaccine that prevents infection and has been available since the early 1960s.
Measles can and does kill. It is especially dangerous in children. In 2017, the most recent year for which official statistics are available, it caused close to 110,000 deaths, according to data from the World Health Organization (WHO).
But a growing belief among some sections of the public that vaccinations can pose a serious risk to health has meant fewer children are being vaccinated - and the number of cases globally is soaring.
Provisional WHO data published in August 2019 shows that reported measles cases rose by 300% in the first three months of this year, compared to the same period in 2018. The WHO directly links the rise in cases to a fall in the number of children receiving vaccinations.
Widening mistrust
While opposition to vaccination is not new, social media has helped to spread anti-vaccine messages in recent years.
Research from the Wellcome Trust, based on a survey of 140,000 people in 140 countries. shows the level of trust in vaccines by country and region.
The study found that worldwide, 79% of people agree that vaccines are safe and 84% agree that they are effective.
Bangladesh and Rwanda have the strongest confidence in vaccines – with almost all people in both countries agreeing that vaccines are safe, effective and that it is important for children to be vaccinated.
In low-income regions, the “proportion of people who agree 'strongly' or 'somewhat' that vaccines are safe tends to be much higher at 80% or above, with highs of 95% of people in South Asia and 92% in Eastern Africa," according to the study.
But as the chart above shows, a lack of trust in vaccines is most common across Europe, including the former Soviet bloc. In France, one in three people don't think vaccines are safe – the highest rate of vaccine mistrust in the world.
Overall, the study found that “in high-income regions, there is less certainty about the safety of vaccines, with 72% of people in Northern America and 73% in Northern Europe agreeing that vaccines are safe. In Western Europe, this figure is even lower, at 59%, and in Eastern Europe it stands at only 40%.”
Mapping measles outbreaks
The consequences of the anti-vaccination movement are now being seen in the growing number of measles cases in almost every region of the world.
There is a correlation between regions with a low level of trust in the safety of vaccines and the number of reported measles cases, according to the WHO. Trust in vaccines in Ukraine is low and it has the second highest number of reported cases in the six months to August 2019. While in Western Europe, France has low faith in vaccines and a high number of cases.
The picture however is not a simple one. The United States has suffered a high number of measles cases, despite relatively solid confidence in vaccines. The WHO reports that “over recent months, spikes in case numbers have also occurred in countries with high overall vaccination coverage, including the United States of America as well as Israel, Thailand, and Tunisia, as the disease has spread fast among clusters of unvaccinated people.”
Achieving herd immunity
To protect the global population against the spread of measles requires a critical level of vaccination. To achieve what is known as herd immunity, research shows that between 93% and 95% of the population must be vaccinated.
With many countries falling short of that figure because of a lack of trust in vaccinations, the spread of measles is likely to continue.