 In the UK, the vaccine is only recommended in people who are particularly vulnerable to chickenpox.As there is an increased risk of shingles in adults due to possible lack of contact with chickenpox-infected children providing a natural boosting to immunity, and the fact that chickenpox is usually a mild illness, the National Health Service cites concerns about unvaccinated children catching chickenpox as adults when it is more dangerous.The varicella vaccine is not recommended for seriously ill people, pregnant women, people who have tuberculosis, people who have experienced a serious allergic reaction to the varicella vaccine in the past, people who are allergic to gelatin, people allergic to neomycin, people receiving high doses of steroids, people receiving treatment for cancer with x-rays or chemotherapy, as well as people who have received blood products or transfusions during the past five months.