A new study has raised concerns that measles could become endemic in the United States once again. In 2000, health experts celebrated the elimination of measles in the U.S. due to a successful measles-mumps-rubella (MMR) vaccination campaign. However, a troubling decline in vaccination rates in recent years has led to a resurgence of the disease, with nearly 900 cases reported in 29 states so far in 2025. Researchers at Stanford University have now conducted a study suggesting that measles could return as an endemic disease in the U.S. if current vaccination trends continue.
The study, published in late April 2025, used epidemiological modeling to predict the spread of infectious diseases, including measles, under various vaccination scenarios. The results indicate that if the MMR vaccination rate drops significantly, the U.S. could face a major resurgence of measles, with the potential for the disease to become endemic once again. Endemic status refers to a situation where a disease is consistently present in a region, but not at the scale of a full-blown pandemic. According to the study’s findings, even a modest decrease in vaccination rates could result in millions of cases, hospitalizations, and deaths over the next few decades.
Currently, the MMR vaccination rate in the U.S. stands at about 93%. However, the study predicts that if vaccination rates were to be reduced by just half, the U.S. could experience 51.2 million cases of measles over the next 25 years. This could lead to 159,200 deaths and over 10 million hospitalizations. In addition, the study estimates that 51,200 children could suffer from long-term nerve-related complications as a result of the disease. Given that measles is one of the most contagious diseases in the world one infected person can spread the virus to 12 to 18 others the potential for widespread transmission is considerable.
The study highlights that even a small reduction in vaccination rates could have a devastating impact. A decrease of just 10% in vaccination coverage could still lead to 11.1 million cases of measles over the same period, with similar consequences in terms of hospitalizations and deaths. This underscores the importance of maintaining high vaccination coverage to protect public health.
On a more optimistic note, the study also suggests that a small increase in vaccination rates could dramatically reduce the risk of a measles resurgence. If the number of people receiving the MMR vaccine increased by just 5%, the number of measles cases over the next 25 years would drop to a mere 5,800. This finding reinforces the idea that every vaccinated person plays a crucial role in preventing the spread of infectious diseases.
The authors of the study emphasize that it is not too late to take action. Vaccination remains the most effective way to prevent measles and protect vulnerable populations. Children are recommended to receive two doses of the MMR vaccine: the first at 12 to 15 months of age and the second between ages 4 and 6. In some cases, if a child is exposed to an outbreak, vaccination may be given as early as 6 months. Adults who have not been vaccinated or are unsure of their vaccination status should consult with a healthcare provider to ensure they are fully protected.
For parents unsure about the safety and importance of vaccinations, the study encourages open discussions with pediatricians to make informed decisions. The research provides important data for policymakers, healthcare officials, and public health advocates to understand the potential consequences of declining vaccination rates and take steps to prevent a resurgence of measles. By making vaccination a priority, it is possible to protect the health of individuals and the broader community from a dangerous and preventable disease.
