Page ContentFlu Vaccine and PregnancyFirst Trimester | Second Trimester | Third Trimester | Postpartum Influenza (the flu) comes on suddenly with headaches, fever, fatigue, muscle aches, coughing, and sore throat. It can lead to complications such as pneumonia. Some complications can be life threatening. Certain people have an increased risk of developing flu complications:Adults over 65 years oldChildren younger than 5 yearsPeople who have illnesses or conditions like asthma, heart disease, or cancerPregnant women Normal changes in the immune system that occur during pregnancy may increase your risk of flu complications such as preterm labor and delivery, hospitalization, and pneumonia. Some of these complications can be life threatening. The Centers for Disease Control and Prevention (CDC) and Kelsey-Seybold Clinic recommend that everyone 6 months of age and older, including pregnant women and women breastfeeding, get the flu vaccine annually. The flu shot contains a form of the flu virus that is inactivated. It can't cause disease. The shot can be given to pregnant women at any time during pregnancy. The vaccine triggers your immune system to make antibodies against the flu virus. Antibodies circulate in the bloodstream. It takes two weeks for the body to build up protective antibodies after you get the flu shot. The flu shot protects both you and your baby as you transfer antibodies that fight infection to your baby. These will help your baby until he or she can get the vaccine at 6 months. If you think you have the flu call your doctor at 713-442-0000 during normal business hours or 713-442-BABY after hours – don't wait!