​Measles is a highly contagious viral infection caused by the measles virus. It primarily spreads through respiratory droplets and affects the respiratory system. Measles can lead to severe complications, especially in vulnerable populations such as young children and immunocompromised individuals, and may result in pneumonia, encephalitis, or even death. In 2021, there were an estimated 128,000 measles deaths worldwide, mostly among under-vaccinated or unvaccinated children under five.​