Measles is a disease which usually produces fever, cough , conjunctivitis ("pink eye", but not quite the same as the "pink eye" seen with colds and earaches), a red, bumpy rash, and a rash ("Koplik's spots") inside the cheeks. It can be complicated by secondary ear infections, diarrhea, croup, and mild pneumonia. In some cases (about 1 out of 1,000) patients with measles develop inflammation of the brain tissue, or "encephalitis". Very rarely, a persistent rubeola infection can produce SSPE, a disease in which nerves and brain tissue degenerate (sometimes many years after the original case of measles); now that we vaccinate most children against measles, SSPE is almost never seen.
Before the vaccine came along, measles epidemics occurred about every 2 years, usually in winter and early spring when unimmune children were together in school, and most measles patients were preschoolers and young elementary-school kids. Nowadays most cases are seen in unvaccinated children (kids younger than 15 months who haven't had the vaccine yet, and preschool kids who should have had the vaccine but haven't) and older children -- some in college -- who received one dose of vaccine but did not become immune as a result. Up to 5% of children who get a single dose of vaccine will not become immune: because of this we now give a second dose of vaccine to all children, usually when they start kindergarten. Measles immune globulin is available and can prevent measles, or at least make it milder than it otherwise would be, if it is given to someone who isn't yet immune within 6 days of exposure.
There are no antibiotics available for treatment of measles. Children who are deficient in vitamin A seem to be more likely to have severe measles (and more likely to die from the infection) than are children with enough vitamin A; therefore the World Health Organization and UNICEF recommend giving 1 to 3 doses of vitamin A to children older than 6 months who have measles and are hospitalized because of measles or its complications or who are malnourished, have immune system problems, or who are proven to have a vitamin A deficiency. Since vitamin A can be toxic in excessive doses, the supplement should only be given on the advice of the child's doctor.
Rubella is a pretty benign disease as viral diseases go: your symptoms usually include a red, bumpy rash, swollen lymph nodes (most often around the ears and neck), and a mild fever; some people also feel achy for a little while. Adolescents and adults, especially women, are much more likely than children to have muscle and joint aches with rubella, but these go away fairly quickly. (It is also possible to have rubella encephalitis, but this is rare.) It takes around 2 to 3-1/2 weeks after exposure to develop rubella.
Unfortunately, if a woman has rubella during the first 3-4 months of her pregnancy, the virus can induce many different birth defects, some of which are quite severe. Among the defects doctors have seen in "congenital rubella" are eye defects (cataracts, glaucoma, and "microphthalmia" (small non-functional eyes) ), heart problems (defects of the wall between the two sides of the heart, narrowing of the arteries to the lungs, and an open duct bypassing the lungs), ear problems (deafness caused by defects in the nerves and sound sensing organs), and neurologic problems (including mental retardation) -- among others. For that reason, obstetricians test every pregnant woman to make sure that she is immune to rubella, and we try to immunize every child to the virus. A single dose of the vaccine usually gives lifelong protection; we usually give two doses (as the combined measles-mumps-rubella, or "MMR", vaccine) to be sure that every child is immune. This helps protect non-immune pregnant women too, by reducing the chances of their being exposed to rubella by sick children. Rubella immune globulin is available and can help decrease the symptoms of rubella, but does not necessarily prevent infection and birth defects in the developing baby: there have been babies born with congenital rubella to mothers who received rubella immune globulin shortly after being exposed to rubella.
We now have a single vaccine that protects against measles, mumps, rubella, and chickenpox. This vaccine, known as "MMRV", is given at the same time as the MMR vaccine is usually given (at age 12-18 months and at age 4-5 years). It appears in trials to work just as well as the separate MMR and chickenpox vaccines, and means fewer needle pokes for a child (which I certainly would have been in favour of when I was that age...). For more information, ask your child's doctor.