Measles Cases are Rising—How Do Mortality and Vaccination Rates Compare?

Measles cases in the United States have reached a 30-year high, prompting concern over the virus's contagiousness and the relationship between mortality and vaccination rates. Measles, declared eradicated in the U.S. in 2000 after a vaccine was developed, has seen occasional annual spikes since then. However, vaccination rates have recently fallen below the 95 percent threshold needed to maintain herd immunity.

Dr. Geetika Sood, a faculty member at Johns Hopkins School of Medicine, emphasized the high contagiousness of the virus, explaining that unvaccinated individuals exposed to measles have a 90 percent chance of developing the illness. At least three people have died this year from measles complications, while the Centers for Disease Control and Prevention (CDC) has confirmed over 3,400 cases across 45 states and Washington, D.C.

Sood anticipates the actual number of cases to be higher, as many unvaccinated individuals might not seek medical attention upon symptom onset. Measles symptoms include high fever, cough, runny nose, and a distinctive rash. Severe complications such as pneumonia and encephalitis, or inflammation of the brain, can also occur. Despite a nationwide vaccination rate of around 93 percent, rates vary significantly between communities, with some regions experiencing lower vaccination levels.

The rise in cases and decline in vaccination rates have raised concerns among experts, who warn that the U.S. measles elimination status, maintained since 2000, could be at risk if transmission continues within the country. Both Dr. Steven Goldberg, chief medical officer at HealthTrack, and Dr. Sood express worry about increased deaths from measles due to falling vaccination rates, noting that even with a low mortality rate, severe complications can arise if the disease spreads widely.