RSV, Flu and COVID in Neonates and Infants

It is officially RSV, Flu, and COVID-19 season!

Last year, we saw a drastic reduction in flu cases because of mask wearing, quarantining, and social distancing due to COVID-19. However, this year, flu outbreaks are back, and can even be coupled with RSV and/or COVID-19 infections. For the very youngest members of our families, these illnesses can pose certain risks particularly those under 1 year of age.

What is a neonate and infant?

Let's discuss RSV, flu and COVID-19 in neonates and infants. A neonatal infant is one who is between 0-28 days of life. An infant is one who is 0 days to 1 year old. These young ages have increased vulnerability to these illnesses because they do not yet have a fully developed immune system.

Learn more from a neonatologist!

I sat down with neonatologist, Dr. Prem Fort @thenicudoc to discuss:

  • RSV, Flu and COVID-19: what is it, what are the symptoms, signs that your baby needs to be seen or go to ER, infants at risk for more severe disease
  • Vaccine recommendations for adults, infants, toddlers and other siblings
  • How to protect infants and children under 2 from infection
  • Having vaccinated and unvaccinated visitors


Respiratory syncytial virus, or RSV, is a common respiratory virus that usually causes mild, cold-like symptoms that might not be severe in the beginning. However, it can become more severe a few days into the illness.

Early symptoms of RSV may include:

  • Runny nose
  • Decrease in appetite
  • Cough, which may progress to wheezing

Most people recover in a week or two, but RSV can be serious, especially for infants and older adults. RSV is the most common cause of bronchiolitis (inflammation of the small airways in the lung) and pneumonia (infection of the lungs) in children younger than 1 year of age in the United States.

Those at greatest risk for severe illness from RSV include premature infants, very young infants (especially those 6 months and younger), children younger than 2 years old with chronic lung disease or congenital (present from birth) heart disease, children with weakened immune systems, children who have neuromuscular disorders, including those who have difficulty swallowing or clearing mucus secretions.

Severe RSV infection

Virtually all children get an RSV infection by the time they are 2 years old. Most of the time RSV will cause a mild, cold-like illness, but it can also cause severe illness such as bronchiolitis (inflammation of the small airways in the lung) and pneumonia (infection of the lungs).

Symptoms of RSV in infants

Infants who get an RSV infection almost always show symptoms. This is different from adults who can get RSV infections and not have symptoms. In very young infants (less than 6 months old), the only symptoms of RSV infection may be:

  • Irritability
  • Decreased activity
  • Decreased appetite
  • Apnea (pauses while breathing)
  • Fever may not always occur with RSV infections


Influenza (flu) is a very contagious viral infection that affects the air passages of the lungs. It is one of the most severe and common viral illnesses of the winter season. Most children are ill with the flu for less than a week, but others have a more serious illness and may need to be treated in the hospital. The flu may also lead to lung infection (pneumonia) or death. For this reason, knowing the symptoms and actively trying to prevent the spread of flu are important for your child’s health.

A flu virus is often passed from person to person through sneezing or coughing. The virus can also live for a short time on surfaces, including door knobs, toys, pens or pencils, keyboards, phones and tablets, and countertops. It can also be passed through shared eating utensils and drinking. Your child can get a flu virus by touching something that was touched by an infected person, and then touching his or her mouth, nose, or eyes. Routinely sanitizing commonly touched surfaces and regular, thorough hand-washing are some of the best defenses.

Symptoms of the flu

The flu is a respiratory disease, but it can affect the whole body. A child can become suddenly ill with any or all of these symptoms:

  • Fever, which may be as high as 103°F (39.4°C) to 105°F (40.5°C)
  • Body aches, which may be severe
  • Headache
  • Sore throat
  • Cough that gets worse
  • Tiredness
  • Runny or stuffy nose

In some cases, your child may also have symptoms such as:

  • Nausea
  • Vomiting
  • Diarrhea

At-risk individuals

Babies under the age of 2 years are more likely to get the flu because their immune systems have not fully developed. They may also have difficulty feeding due to congestion, which can lead to dehydration. Productive coughing can be difficult for babies and pneumonia can develop quickly.

Children younger than 6 months old have the highest risk for being hospitalized from flu compared to children of other ages because they are too young to get a flu vaccine. Because flu vaccines are not approved for use in children younger than 6 months old, protecting them from flu is especially important. As a result, flu vaccination in pregnancy or lactation, as well as having any adults around the baby vaccinated against the flu, is very important.


Babies under age 1 might be at higher risk of severe illness with COVID-19 than older children. This is likely due to their immature immune systems and smaller airways, which make them more likely to develop breathing issues with respiratory virus infections.


Among children age 0 through 9 years, symptoms can be as follows:

  • Fever, cough, or shortness of breath
  • Myalgia
  • Rhinorrhea
  • Sore throat
  • Headache
  • Nausea/vomiting
  • Abdominal pain
  • Diarrhea
  • Loss of smell or taste

Do babies have antibodies after COVID-19 or vaccination in pregnancy?

It’s not recommended for babies to get tested for antibodies, but preliminary studies show that pregnant parents who received the vaccine while pregnant likely passed antibodies on to their babies. However, we don't know how protective these antibodies are or for how long they are protective. For these reasons, experts don’t recommend relying on the probability of the baby having antibodies to make choices about precautions, but instead to take the precautions anyway.

How to protect infants from getting COVID

COVID-19 can spread when people breathe, talk, cough, or sneeze, even for people who feel fine and have no symptoms — they can still be infected and not know it. When someone wears a mask, it keeps the virus from reaching other people if they are infected, and also protects them from catching the virus from others.

Key steps to protecting infants from getting COVID-19 include:

  • getting a vaccine when possible
  • social distancing (also called physical distancing)
  • washing hands well and often
  • mask-wearing (children over age 2)

*Children under age 2 can’t wear masks or get a COVID-19 vaccine. Having those who are old enough wear a mask when around newborns and young infants can help reduce the spread of COVID-19.

Listen to my discussion with Dr. Prem Fort!

Frequently Asked Questions

What are your qualifications?

I am a double board certified ObGyn and Maternal-Fetal Medicine Specialist. I have worked at a large academic center in academic medicine as a clinician, educator and researcher since 2004.  I am currently a tenured Professor and actively manage patients with high-risk pregnancies.

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