Diseases beginning with R
U.S.-focused summaries with current official guidance links. For a diagnosis, personal vaccine schedule, pregnancy advice, or urgent symptoms, speak with a qualified clinician.
Rabies
Exposure/travel vaccineDisease
A virus transmitted through saliva from infected mammals, usually through a bite or scratch.
Symptoms
Early fever, headache, and tingling at the bite may progress to anxiety, confusion, difficulty swallowing, hydrophobia, paralysis, or coma.
Typical duration
Incubation is often weeks to months. Once neurologic symptoms start, disease progresses rapidly.
How serious is it?
Almost always fatal after symptoms begin, but prompt prevention after exposure is highly effective.
Treatment & management
Wash the wound immediately and seek urgent care/public-health advice. Post-exposure prophylaxis depends on prior vaccination and includes vaccine, sometimes with immune globulin.
Vaccine: who and when?
Products: Imovax Rabies and RabAvert. Pre-exposure vaccination for eligible risks uses two doses on days 0 and 7, with titer or booster options for continued risk. An unvaccinated person who is exposed generally needs wound care, rabies immune globulin, and vaccine on days 0, 3, 7, and 14; immunocompromised people may need an additional dose.
Rotavirus
Routine childhood vaccineDisease
A highly contagious virus that causes gastroenteritis, especially in infants and young children.
Symptoms
Severe watery diarrhea, vomiting, fever, stomach pain, and dehydration.
Typical duration
Symptoms usually last three to eight days.
How serious is it?
Dehydration can require emergency or hospital treatment, especially in babies.
Treatment & management
Oral fluids are central; severe dehydration may require intravenous fluids. Antibiotics do not treat rotavirus.
Vaccine: who and when?
Products: RotaTeq, a three-dose oral series, and Rotarix, a two-dose oral series. Doses start at about 2 months; the first must be given before 15 weeks of age and all doses completed by 8 months.
RSV
Age/risk-based preventionDisease
Respiratory syncytial virus, a common cause of cold-like illness that can affect the small airways and lungs.
Symptoms
Runny nose, reduced appetite, cough, sneezing, fever, wheezing, or breathing difficulty; very young infants may show irritability or pauses in breathing.
Typical duration
Most improve in one to two weeks, though cough can last longer.
How serious is it?
Can cause bronchiolitis and pneumonia; infants, older adults, and people with certain conditions face higher risk.
Treatment & management
Most care is supportive. Breathing difficulty, dehydration, bluish color, or worsening illness needs urgent assessment.
Vaccine: who and when?
Adult vaccine products include Abrysvo, Arexvy, and mRESVIA, generally given as one dose to people eligible under current age- and risk-based guidance. Only Abrysvo is used during pregnancy, at 32-36 weeks during the recommended season. Infant protection may instead use the monoclonal antibodies Beyfortus or Enflonsia; most infants do not need both maternal vaccination and an antibody.
Rubella
Routine vaccineDisease
A contagious viral infection that is often mild but is dangerous during pregnancy.
Symptoms
Low fever, sore throat, rash, red eyes, swollen lymph nodes, headache, or joint pain; many have few symptoms.
Typical duration
The rash usually lasts about three days.
How serious is it?
In pregnancy it can cause miscarriage, stillbirth, or severe congenital rubella syndrome.
Treatment & management
No specific antiviral; care is supportive. Exposure during pregnancy requires prompt medical/public-health advice.
Vaccine: who and when?
Products: M-M-R II and Priorix, both MMR vaccines. Children routinely receive two doses. MMR is a live vaccine and is not given during pregnancy; immunity should be addressed before pregnancy or after delivery with clinician guidance.
Last reviewed against official U.S. sources: September 5, 2026. This page provides general education, not medical advice.