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Is Your Newborn Baby’s Immune System Strong Enough?

How to protect your little one from bacteria and viruses

Seated mother holds small baby facing toward her as they smile at one another

You soothe your newborn baby’s cries, and you revel in their first smile. They need you for everything — and you want to protect them from everything — but how do you safeguard their still-developing immune system from sickness and flu?

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“It’s important to consider, especially in the early weeks of a baby’s life,” says pediatrician Camille Sabella, MD.

“An infant’s immune system doesn’t mature until they’re about two to three months old,” Dr. Sabella says.

“In those first few months, the immune system — especially cell-mediated immunity — becomes more developed. This is very important in helping a child fight off viruses.”

This means that a 2-week-old baby’s immune system can’t fight viruses or bacteria nearly as well as a 3-month-old’s can.

On the bright side, the mother’s immune system does continue to protect her infant with antibodies that were shared through the placenta immediately after birth. “Those antibodies stay active for the first few weeks of a baby’s life,” Dr. Sabella says.

This offers some protection from bacteria and viruses. Breastfeeding also boosts this early immunity.

Know when to call a doctor about your baby’s sickness

There are plenty of ways to help cut down your baby’s risk of sickness.

For starters, know when you absolutely should call a doctor. This includes any of the following signs:

  • Difficult breathing.
  • Bluish skin or lip color.
  • Dehydration.
  • Fever.
  • Lethargy or failure to wake up.

Your baby’s vulnerability to viruses

Keep in mind that new babies are vulnerable to viruses. Here are some of the most common to watch out for:

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  • Stomach virus. “Gastrointestinal viruses can present significant problems for infants,” Dr. Sabella says. They can cause dehydration resulting from diarrhea. These bugs also can quickly spread to the bloodstream if they strike during a baby’s first month of life. That kind of infection can cause liver damage, meningitis, encephalitis and heart inflammation.
  • Respiratory syncytial virus (RSV)Infants under six months of age who get this virus are often hospitalized. It can cause bronchiolitis, a condition where the small airways in the lungs swell block air flow and fill with mucus. RSV also causes pneumonia.
  • Flu. Infants get sicker with the flu than older children and adults do. “Although there is potential treatment of the flu virus, it often can turn into pneumonia or apnea,” Dr. Sabella says.

3 ways to reduce your baby’s risk of sickness

“There are things you can do to protect your baby during the first few months of life,” Dr. Sabella says.

1. Limit outside exposures

You can’t keep your baby in a bubble until they reach the six-month mark. But you can limit contact with other people. And ask visitors to wash their hands before touching the child.

“The first two months of life, we really regard as a sacred time to try to limit exposures as much as possible because babies can get viruses from people who don’t even know they’re contagious yet,” he says.

2. Watch for fever

In babies under 3 months, a rectal temperature of 100.4°F (38°C) or higher needs prompt medical evaluation. Depending on their age and exam findings, your clinician may recommend tests and sometimes antibiotics while results return.

3. Keep up with vaccines

Many pediatricians recommend starting routine infant vaccines at the 2-month visit to reduce the risk of serious infections. In particular, DTaP (protects against pertussis/whooping cough), Hib, and pneumococcal (PCV) help lower the risk of severe illness like meningitis and bloodstream infections in young infants.

If you’re expecting, ask your OB about Tdap during pregnancy (often in the third trimester), which can help protect your newborn from pertussis before they’re old enough for their own shots.

If you’re weighing timing or have questions, talk with your pediatrician about your baby’s health history and the plan that fits your family.

Bottom line

Stay aware, use common-sense precautions and reach out to your pediatrician when you’re unsure. That partnership goes a long way in the first months.

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