August 12, 2021/Children's Health

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 fragile 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:

  • 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. It’s difficult for doctors to determine whether a virus or bacteria is causing an infant’s illness. So, they err on the side of caution. “Any fever — 100.4 degrees F or higher — will likely land your baby in the hospital for IV antibiotic treatment,” Dr. Sabella says. In some cases, doctors will order a spinal tap to rule out meningitis.

“Our ability to distinguish between a virus and a bacterial infection right up front is limited,” he says. “We often have to do everything and treat it to rule out worst-case scenarios.”

3. Keep up with vaccines. “Keeping your infant up-to-date with vaccines is critical to their health,” Dr. Sabella says, “Especially during the COVID-19 pandemic.”

The whooping cough (pertussis) vaccine is particularly important. The illness is life-threatening for a child under six months of age. “Babies should receive the vaccine first at two months,” he says.

Hib and Prevnar vaccines protect against bloodstream infections and meningitis.

If you’re reading this before having your child, consider getting the flu vaccine. It isn’t given to infants. But vaccination for the mother during pregnancy protects the baby as well.

Being aware, taking common-sense precautions and connecting with a doctor as needed all can help protect your newborn baby. It’s better to be safe than sorry.


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