Originally published 2017-11-28.
For several years the Council on Foreign Relations (CFR), a US foreign-policy think tank, ran an interactive world map that plotted outbreaks of five diseases that vaccines can prevent: measles, mumps, rubella, polio and whooping cough (pertussis). Each dot marked a reported outbreak, and the picture it painted was uncomfortable. Diseases that cheap, well-tested vaccines can stop were still appearing on every continent, including in rich countries where vaccines are easy to get.
The map did not prove that every case came from a family refusing vaccines. It showed where outbreaks were reported, and reporting varies a lot from country to country. But it made one point very clear: when vaccination rates fall, these infections come back quickly. Here is what the map showed, how the modern anti-vaccine movement grew, and what the latest global figures say.
What the CFR outbreak map tracked
CFR's Global Health Program launched the map in October 2011 after about three years of work, with funding from the Bill & Melinda Gates Foundation. Laurie Garrett, then CFR's senior fellow for global health, led the project. Her team gathered reports from news media, governments and international health bodies, and users could filter the results by region, year and disease. An embeddable copy was also offered to media outlets, which is how many readers came across it on sites such as Vaccines Work.
By 2014 CFR said new reports were added to the map weekly and had drawn nearly a million visits. That year it also began showing attacks on vaccinators and other health workers alongside the outbreaks, because such violence had been rising since the tool first appeared. Garrett said at the time that polio's resurgence in Pakistan was strongly correlated with those attacks.
When the map was widely shared in 2017, its data ran from 2008 onward.
The patterns it revealed
Several trends stood out to anyone who explored it:
- Africa had the largest outbreaks, mainly because of weak health systems and supply problems, not because of vaccine refusal.
- Measles and whooping cough were rising in wealthier countries, especially the United States and the United Kingdom, where vaccine hesitancy and gaps in booster coverage played a role.
- Polio held on where vaccination campaigns were disrupted, notably in Pakistan and Afghanistan, the last countries where wild poliovirus has never been interrupted.
In other words, two very different problems produced similar dots on the map. In poorer regions people often could not get vaccines. In richer regions some people could get them but chose not to.
How deadly these diseases are
It is easy to forget how dangerous these infections were before mass vaccination. Measles is among the most contagious diseases known: according to the World Health Organization (WHO), one infected person can pass it to as many as 18 others, and the virus can linger in the air or on surfaces for up to two hours. It can cause pneumonia, brain swelling (encephalitis), blindness and severe dehydration, and it is most dangerous for children under five.
Estimates of measles deaths have changed over time. When CFR launched the map in 2011 it cited about 164,000 deaths a year. A few years later the US Centers for Disease Control and Prevention (CDC) put the global toll at roughly 146,000. WHO now estimates about 95,000 measles deaths in 2024, most of them young children. The decline reflects real progress: WHO says measles vaccination averted nearly 59 million deaths between 2000 and 2024.
Whooping cough is a particular danger to babies too young to be fully vaccinated. An older global estimate used by the CDC put pertussis deaths at about 195,000 a year, overwhelmingly in low-income countries. Even in wealthy countries, infants still die from it each year, which is why many health services now offer a pertussis vaccine during pregnancy to protect newborns.
Where the MMR scare began
Much of today's distrust of the measles, mumps and rubella (MMR) vaccine traces back to a single paper. On 28 February 1998 The Lancet published a study by Andrew Wakefield and 12 co-authors describing 12 children with developmental and bowel problems and suggesting a link with MMR. Even the paper admitted that it had not proven an association.
The claim fell apart step by step:
- Later studies could not reproduce the findings, and a Medical Research Council expert panel quickly found no evidence of a link.
- In 2004 journalist Brian Deer revealed that Wakefield had been paid by a lawyer preparing legal action against vaccine makers, a conflict he had not disclosed. Ten of the co-authors withdrew the paper's interpretation.
- In January 2010 the UK General Medical Council found that Wakefield had acted dishonestly and irresponsibly. The Lancet fully retracted the paper on 2 February 2010, and he was struck off the medical register that May.
- In January 2011 the BMJ published Deer's evidence that details of all 12 children had been altered, and the journal called the study fraudulent.
The damage was already done. MMR uptake dropped sharply in the UK and Ireland after 1998, and measles and mumps returned, causing serious illness and deaths. Large studies involving hundreds of thousands of children have since found no link between MMR and autism.
Herd immunity and the people it protects
Vaccines protect the person who receives them, but they also protect others. When enough people in a community are immune, a disease struggles to spread, so even those who cannot be vaccinated are shielded. This is called community or herd immunity.
Some people genuinely cannot have certain vaccines: very young babies, people having chemotherapy, and those with particular immune conditions or severe allergies. They rely on everyone around them. For measles, which spreads so easily, public health agencies commonly aim for about 95 per cent of children to receive two doses. Small drops below that level can lead to large outbreaks, a point Garrett made when the map launched.
Like any medicine, vaccines can have side effects. Most are mild, such as a sore arm or a short fever, and serious reactions are very rare. Anyone with questions about their own or their child's vaccinations should talk to a doctor or nurse.
Common myths, briefly answered
- "These diseases are gone, so vaccines are not needed." They are rare in many places because of vaccination. Travel brings them back within hours, and outbreaks follow wherever coverage slips.
- "Natural infection is better." Catching measles does give immunity, but at the risk of pneumonia, brain damage or death, and it can weaken the immune system's memory of other infections for months or years.
- "MMR causes autism." The study behind this claim was retracted as fraudulent, and many large studies have found no link.
Measles today
Since the map was widely shared, global progress has stalled. WHO reports that 84 per cent of children received a first dose of measles vaccine in 2025, slightly below the 86 per cent of 2019, and only 77 per cent received both doses. WHO and UNICEF estimate that about 29 million infants were under-protected against measles in 2025.
The CFR map is no longer the best place to follow outbreaks, but its message holds up. Every gap in vaccination, whether caused by conflict, poverty or misinformation, eventually shows up as a cluster of cases somewhere on a map.
Sources: CFR, 24 October 2011: CFR launches interactive map tracking vaccine-preventable disease outbreaks; CFR, October 2014: Vaccine-preventable outbreaks map shows attacks on vaccinators drive polio; WHO fact sheet: Measles; Wikipedia: Lancet MMR autism fraud; BMJ, 2011: How the case against the MMR vaccine was fixed; CDC: Measles data and statistics; earlier coverage by IFLScience.
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