Are you missing cases of measles, mumps, rubella, or varicella in your clinical practice without even knowing it? With declining vaccine rates, it is more important than ever to spot vaccine-preventable illnesses, diseases you may have only ever seen on board questions! Dr. Walter Dehority, a pediatric infectious disease physician at the Monroe Carell Jr. Children's Hospital at Vanderbilt and an expert in vaccines, walks us through need-to-know pearls about the MMR-V suite, including how to spot measles before your colleagues do and which complications should make you think mumps, even without the stereotypical swelling.