Introduction Vaccines have revolutionized public health by drastically reducing the spread of once-deadly diseases. Among the most important is the MMR vaccine, which protects against measles, mumps, and rubella—three highly contagious viral infections. With recent outbreaks of measles in parts of the world, there has been renewed attention on the MMR vaccine. This article explores how the MMR vaccine works, its safety and effectiveness, and why widespread immunization is critical for herd immunity. What Is the MMR Vaccine? The MMR vaccine is a combination vaccine that protects against: The vaccine contains live, weakened forms of the viruses that trigger the…