A. The greatest risk to your daughter comes from respiratory syncytial (sin-SISH-al) virus, also known as RSV, which usually manifests as a cold, but can sometimes progress to a serious illness. More than half of all babies will catch RSV their first winter, and by 2 years of age, 95 percent of children will have had the virus.
RSV is spread by close contact with someone who is infected or with contaminated surfaces and objects (the virus can live for half an hour or more on hands and even longer on used tissues or countertops). So the best thing you can do for your baby this season is to wash your hands frequently and avoid crowds and people with colds. Other risk factors include attendance at daycare, school-age siblings, or exposure to tobacco smoke. Breastfeeding offers some protection against severe illness.
While most infected infants, as well as older children and adults, experience only a cold, an estimated 90,000 children (most of whom are between 6 weeks and 6 months of age) are admitted to the hospital each year for severe RSV disease like pneumonia or bronchiolitis. Infants with certain medical problems (prematurity, chronic lung disease, congenital heart disease, and impaired immunity) are especially susceptible to developing severe illness with RSV, which is linked to chronic respiratory symptoms, including asthma, later in life.
To protect your child, you need to know how to distinguish a minor cold from symptoms of something more serious. If your child has a cold as well as any of the following, call your doctor, since your child may need further treatment.
Infants with RSV pneumonia or bronchiolitis may need to be hospitalized and given supplemental oxygen or intravenous fluids.
Influenza is another serious respiratory illness that peaks each winter. It's highly contagious and is spread from person to person mainly by coughing and sneezing as well as direct contact. Flu viruses infect people of all ages, but very young children, the elderly, and anyone with certain medical conditions (talk to your doctor about which ones) are at greatest risk for complications leading to hospitalization and, in some cases, death.
Older children may have a mix of fever, muscle aches, a dry cough, fatigue, and a headache, but in babies, the main indicator of flu is fever along with respiratory symptoms like a cough. While RSV and influenza can look similar in infants, diagnostic tests are available to distinguish the two, so call your doctor if your baby becomes ill.
The major strategy for preventing the flu has been the use of an annual vaccine, recommended for those at high risk. This year, the Advisory Committee on Immunization Practices of the Centers for Disease Control and Prevention has identified a new group of potential vaccine recipients: Healthy children aged 6 to 23 months are "encouraged" to receive the vaccine, as are their caregivers. (A formal recommendation for this age group is expected to follow within a few years.) Have your baby immunized right away -- this month, if possible. (Babies being immunized for the first time require two doses, given one month apart.) You'll need to have your child revaccinated each year to maintain immunity.
The most common side effect of the vaccine is soreness at the site of the injection, although fever, irritability, and other symptoms may occur. Because the vaccine is produced from viruses grown in eggs, it may contain a small amount of egg protein that could cause an allergic reaction in anyone with a severe egg allergy; check with your doctor.