Q: I am a 36 years old married woman. I have a mild form of chicken pox as a result of the chicken pox vaccine I took 2 weeks back. I am taking rest and taking Tylenol. I would like to know if I need to take the second vaccine now? Will I be at risk for shingles later? My 2 children aged 4 and 2 have also had the vaccine with me. Will they contract it too?

A:Chickenpox (varicella) is an infectious disease caused by the varicella-zoster virus of the herpes family. The disease results in a blister-like rash, itching, tiredness and fever. It is a highly infectious disease that spreads from person to person by direct contact or through the air from an infected person’s coughing or sneezing. A patient with chickenpox is contagious 1-2 days before the rash appears and until all blisters have formed scabs. It takes from 10-21 days after contact with an infected person for someone to develop chickenpox. Shingles, or herpes zoster, is caused by reactivation the chickenpox virus that remains in the nerve roots of all persons who had chickenpox and can flare up later in life to cause illness. It is associated with normal aging and with anything that weakens the immune system such as certain medications, cancers, infections or inborn disorders. Studies suggest that shingles is less common in vaccinated healthy persons compared with persons who have had natural chickenpox. The varicella vaccine is 85 percent effective in preventing disease. If a vaccinated person gets varicella, it is usually a very mild disease. The recommended strategy is to vaccinate children routinely at age 12 to 18 months and to provide catch-up vaccinations for older children, adolescents, and adults who have not been vaccinated. Studies show that immunity persists for more than 20 years after vaccination. All children between 12 and 18 months of age should have one dose of chickenpox vaccine. Children who have had chickenpox do not need the vaccine. Children between 19 months and their 13th birthday who have not had chickenpox should be vaccinated with a single dose. Individuals 13 years and older who have not had chickenpox should get two doses of the vaccine 4 to 8 weeks apart. About 20% individuals get soreness, redness, or swelling at the vaccination site while less than 5% people may get a very mild rash. It has been documented that very rarely a vaccine recipient who develops a rash following vaccination may transmit the vaccine strain chickenpox to another person. If you have developed a rash after vaccination please take extra precautions to avoid contact with individuals with low immunity. Despite vaccination about 10% individuals do not develop enough protection to completely prevent them from developing chickenpox. When they come into close contact with a person with chickenpox, they may develop a mild case of disease but compared with a case of chickenpox in an unvaccinated individual, they will show very little sign of illness.