In early 2026, health officials in the United States have sounded alarms over a resurgence of mumps infections, highlighting a broader and concerning trend: the return of vaccine-preventable diseases. Maryland, among at least 11 states reporting cases, has been particularly affected, with 26 confirmed infections by mid-February. This resurgence underscores the ongoing challenges posed by declining vaccination rates and the potential public health risks that follow.
Mumps is a contagious viral infection primarily affecting the salivary glands located near the ears, leading to the characteristic painful swelling of the jaw. The virus spreads easily through respiratory droplets and saliva, transmitted by coughing, sneezing, talking, or sharing utensils. After infection, symptoms typically take two to four weeks to appear. Besides the noticeable swelling, mumps can cause fever, headache, muscle pain, and other flu-like symptoms. While children often experience mild or even asymptomatic cases, teenagers and adults are more likely to endure severe illness. There is no targeted antiviral treatment for mumps; care focuses on symptom management through rest, hydration, and pain relief.
One of the most distressing complications of mumps is orchitis, an inflammation of the testicles that can negatively impact male fertility. Other possible complications include oophoritis and mastitis—inflammation of the ovaries and breasts, respectively. Although rare, mumps can also lead to meningitis or encephalitis, serious conditions involving inflammation of the brain or its protective lining. Additionally, permanent hearing loss is a documented risk. Importantly, individuals who have not been vaccinated against mumps face higher risks both of contracting the disease and suffering from its complications.
The mumps vaccine has a long history of success in controlling the disease. Since the introduction of the first vaccine in 1967, cases in the U.S. have dropped by approximately 99 percent. However, outbreaks still occur, particularly in environments where people are in close contact, such as schools, universities, and correctional facilities. This vulnerability is compounded by waning immunity over time and gaps in vaccine coverage.
To protect against mumps, public health guidelines recommend that children receive two doses of the combined measles, mumps, and rubella (MMR) vaccine—the first between 12 and 15 months of age and a booster between four and six years old. Two doses provide about 86 percent effectiveness in preventing mumps, while a single dose offers approximately 72 percent protection. Despite vaccination, some vaccinated individuals may still contract the virus, especially as immunity diminishes with age, but their symptoms are generally milder compared to those unvaccinated.
The recent spike in mumps cases is part of a larger pattern involving other vaccine-preventable diseases, such as measles, which has seen a significant increase in outbreaks over the past year. This trend has been linked in part to declining vaccination rates among children, a decline fueled by growing vaccine hesitancy and misinformation that escalated during and after the COVID-19 pandemic. The erosion of herd immunity poses risks not only to those who refuse vaccines but also to vulnerable populations who cannot be vaccinated for medical reasons.
Experts emphasize the critical role of vaccines in preventing these diseases and urge the public to adhere to recommended immunization schedules. Vaccination remains the most effective tool to curb the spread of mumps and its potentially serious health consequences. Public health officials continue to monitor the situation closely, issuing alerts and guidance to contain outbreaks and protect communities.
The resurgence of mumps serves as a stark reminder that the progress made against infectious diseases can be fragile. Sustained efforts in education, vaccination advocacy, and public health infrastructure are necessary to maintain control over these illnesses. As the nation confronts the challenges of vaccine hesitancy and misinformation, the medical community remains committed to promoting science-based interventions to safeguard public health.
Tanya Lewis, a senior health and medicine editor at Scientific American, highlights the importance of continued vigilance and support for vaccination programs. Her perspective underscores the broader mission of scientific communication: to inform, educate, and inspire confidence in evidence-based health measures. The ongoing outbreaks of mumps and other preventable diseases reaffirm the need for a collective commitment to science and public health.
In conclusion, the recent increase in mumps infections across multiple states, including Maryland, signals a troubling resurgence of diseases once well-controlled through vaccination. The decline in immunization rates has reopened the door for outbreaks, threatening individual health and community safety. Maintaining high vaccine coverage and public awareness are essential to