Interview with RSV Expert Dr. Natalie Mazur

Dr. Natalie Mazur on strategies for preventing RSV

Dr. Natalie Mazur has been involved in RSV research for 8 years. Under the supervision of prof. Louis Bont she obtained her PhD, which was focused on, among others, global mortality due to RSV, and the development of vaccines against this virus. Currently she is working as postdoctoral researcher, and drawing attention to the importance of making vaccines accessible in the developing world. In addition, she is a paediatric resident in training. She has a passion for global health and the movement of scientific discoveries into clinical applications. We spoke with Natalie about the spreading of RSV and preventive measures that can help to prevent a child from getting a (severe) RSV infection.

Hands are the most important culprit
“RSV is spread through contact with droplets, either through direct contact when there is physical contact with an infected person, for example by kissing someone on the mouth, or indirectly by transmission of infected droplets and snot from your hands to your eyes, nose or mouth. Therefore, hands play a very important role in the transmission of RSV. It depends on the type of surface how long RSV survives: RSV can survive for approximately 7 hours on hard surfaces such as light switches, tables, door knobs and toys. On soft surfaces, such as skin, clothes and tissues, it typically lives for a shorter time, approximately one hour. RSV is spread from person to person. There is a virus that is closely related to RSV, the so-called bovine RSV which can be found in young cows, but as far as we know, this virus cannot infect humans like COVID-19, which can be transferred from minks to people.”

Handwashing and cleaning
​“Washing your hands correctly and regularly is the key in RSV prevention. If you are not able to wash your hands, it is important to avoid touching your eyes, nose or mouth. Furthermore, it is best to avoid cuddles and kisses between your baby and people who are having a cold. It can be helpful to regularly disinfect toys and throw away used nose wipes as soon as possible. How often you should clean toys depends on how many strangers touch them, or on if there is snot on them. Toys that are touched by a lot of different children should be cleaned more regularly than those that are only used by your own child.

The most important places to disinfect are, in addition to your hands, hard surfaces that are touched often. RSV lives longest on these surfaces. Hard surfaces that are frequently touched by adults are light switches, pens and door knobs. For children, you should think of toys, bed frames and highchairs.”

Receiving visitors and nurseries
Almost every child will be infected with RSV before the age of 2. After the first infection, you can recurrently get infected. The first 6 months after birth, the risk of developing pneumonia or need for hospital admission is highest. After this age, symptoms of infection are more often less severe, for instance a cold or ear infection. There is no clear cut-off age after which visitors safely hold and touch your baby. Rather, it is most important to ask visitors to wash their hands before touching your baby, and to keep people who are having a cold away until they are not sick anymore.

Certain groups of children are at higher risk of severe disease when they get infected with RSV. These are for instance premature babies or babies with Down’s Syndrome. Nevertheless, the measures to prevent these children from getting RSV are the same as for other children, although it is more important to avoid children in these risk groups from getting RSV.

Parents should decide for their own when they want to take their child to nursery. The risk of getting RSV will be higher, because your child will be in contact with many other children and will therefore more often meet children who have a cold. However, nowadays this risk may be lower, as a lot of children must stay at home when they have a cold. In the first 6 months after birth, the risk of severe RSV infection is highest. A lot of children will go to nursery when they are 3-4 months old, so a risk for severe RSV infection remains between 4-6 months of age. It is up to the parents whether they feel it’s best to keep their child at home for a longer period of time. A nursery is important for the development of a child and the ability to combine work with a family.

Siblings
“Children with siblings are at higher risk of getting RSV, because siblings can be exposed to RSV in school or child-care centers and transmit the virus to other members of the family. The most important measure to prevent siblings from transmitting the virus to you baby is by letting them wash their hands well. Furthermore, it can be helpful to avoid siblings from touching each other’s toys  when they have a cold.”

Is exposure to viruses beneficial?
“By being exposed to viruses, children build up their immune system. However, children aged younger than 6 months are most vulnerable for severe RSV infection. Ideally, a child is exposed to the virus after this age, so they can build up immunity against the virus. This would change when a vaccine will become available to protect young children from RSV.

RSV infection is harmless for pregnant women and their unborn babies. Rather, when women in the second or third trimester of their pregnancy are infected with RSV, antibodies will pass through to the unborn baby, which provides protection during the first couple of weeks after birth. It is extremely rare for a pregnant woman to become severely ill after RSV infection. Therefore, you could say that infection during pregnancy has more pros than cons.

Breastfeeding protects children against severe airway infections, including RSV. It has been shown that children who are on formula are at higher risk of getting severe airway infections. Especially in the critical period of the first 6 months after birth breastfeeding is important. However, this is a recommendation, and of course dependent of the feasibility to breastfeed.”
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Smoking
“Research has shown that if someone smokes in a child’s environment , the risk of hospital admission due to RSV infection increases, and that there is a higher risk of a severe illness. The exact mechanism is unclear, but it could be due to inflammation of the airways, that could make the lungs more susceptible for RSV infection. Mothers who smoke during pregnancy are at increased risk of having a child with a severe RSV infection, because smoking affects development of the lungs.”

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