Groups of people who shouldn’t get the vaccine include: people who have severe allergies to eggs, chicken proteins, or gelatin infants younger than 6 months old people who have HIV, AIDS, or other conditions that compromise the immune system If you’re older than 60 and you’re considering traveling to an area that may have the virus, you should discuss vaccination with your doctor. If you’re traveling with an infant who is 6 to 8 months old or you’re a nursing mother, you should either postpone travel to these areas if possible or talk to your doctor about vaccination. The vaccine is considered extremely safe. A single dose provides protection for at least 10 years. The side effects may include: a mild headache muscle pain fatigue a low-grade fever Other methods of prevention include using insect repellant, wearing clothing to reduce the amount of mosquito bites, and staying inside during peak times when insects bite.