What should you know about MMR, Tdap and varicella?

MMR helps protect against measles, mumps and rubella; Tdap helps protect against tetanus, diphtheria and pertussis; varicella vaccination helps prevent Chickenpox. Soreness at the injection site, tiredness or a low fever may occur as the immune system responds. A delayed mild rash can occur after some live vaccines, but a new rash is not automatically caused by vaccination. Fever with widespread blisters can also fit an infection, including chickenpox, so the full pattern matters.

Shingles is a separate condition caused by reactivation of varicella-zoster virus, not simply the same rash seen after every vaccine.

Rest, drink fluids and wear comfortable clothing. Keep the injection area clean and avoid rubbing it. If fever or soreness develops, use only medicines suitable for the person’s age, health and other medicines; a pharmacist or clinician can help choose. Photograph a changing rash and record which vaccine was given, the timing, temperature, and symptoms such as itch or blisters. Avoid close contact with people who may be medically vulnerable until a clinician has clarified an unexplained blistering rash.

Call emergency services for wheezing, difficulty breathing, facial or throat swelling, collapse, or rapidly worsening weakness. Obtain urgent medical advice for widespread blistering, skin peeling, a rash involving the eyes or mouth, persistent vomiting, severe headache, confusion, or a child who is unusually sleepy. A fever with new blisters should be assessed, especially when the person is pregnant, very young, immunocompromised, or has a serious long-term condition.

Ask which vaccine best explains the timing, how to distinguish a normal injection reaction from infection, and whether the person should avoid school or close contact. Clarify what to use for fever or itch, when to arrange a GP Consultation, and whether a previous reaction changes the plan for future doses.