Influenza Vaccination: Special Considerations in Pediatric Patients
Younger children are generally more susceptible to influenza than are older children and young adults. Vaccinating children offers them protection against influenza and may also benefit other at-risk populations through the phenomenon of herd immunity. Our featured experts discuss these and other special pediatric considerations surrounding influenza vaccination.
Q: What are some of the distinctly pediatric considerations in influenza vaccination?
Professor, Department of Pediatrics
“All of the influenza vaccines are safe and effective when used in accordance with the product labeling and recommendations. Vaccination remains the best way to prevent influenza and related illness in children and in the general public.”
Influenza vaccination in accordance with the yearly guidance is important for every patient. Since influenza is a highly communicable disease, appropriate vaccination of all age groups is the best approach to prevention. Immunization is especially important in pediatrics because younger children have a much higher risk of hospitalization and complications from influenza than do older children and young adults. It is important to note the distinct pediatric age groups when vaccinating. For infants under 6 months of age (ie, too young to receive the influenza vaccine) the vaccination of household contacts is an important strategy to help prevent this age group from getting influenza and possibly suffering associated complications. Moreover, matching the type of vaccine with the particular child and the appropriate age group is important. Some vaccines are intended for use in children as young as 6 months old, while others may be used starting at 2 years old or can only be used in older age groups. Inactivated influenza vaccines are available for infants as young as 6 months old. The live attenuated influenza vaccine (LAIV), which is a nasal spray vaccine, is approved by the US Food and Drug Administration for use in people aged 2 to 49 years and is an option for generally healthy, nonpregnant people in this age group. Although the nasal spray influenza vaccine can be given to people with mild illnesses, people with certain medical conditions should not receive the nasal spray influenza vaccine. It is a live attenuated vaccine that works by replicating in the nasopharynx to induce immunity. Precautions include that it should not be administered to children under 2 years old or to children aged 2 to 4 years who have asthma. All of the influenza vaccines are safe and effective when used in accordance with the product labeling and recommendations. Vaccination remains the best way to prevent influenza and related illness in children and in the general public.
Professor of Clinical Pediatrics
“Influenza vaccination can not only reduce the risk of contracting influenza, but also the risk of influenza-associated hospitalization, and this is true for children, working-age adults, and older adults.”
We are learning that there is some cross-protection, and even long-term protection, that occurs as you experience either vaccination or natural influenza infection, and young children have not lived long enough to experience the variation in strains that older children and adults have. Thus, they are immunologically naïve and more susceptible to influenza. Our approach to pediatric immunization should begin even before babies are born. Expectant mothers can be immunized with the inactivated influenza vaccine (not the LAIV), which can also help to protect a baby after birth, as maternal antibodies are passed on to the developing baby during the pregnancy. I would add that it is important to realize that children are good vectors for the spread of disease and that herd immunity from immunizing these children can result in a public health benefit that may extend to older adults (eg, those aged ≥65 years, those with chronic health issues) who are also at higher risk for influenza and its complications. Influenza vaccination can not only reduce the risk of contracting influenza, but also the risk of influenza-associated hospitalization, and this is true for children, working-age adults, and older adults.
Associate Professor of Pediatrics and Infectious Diseases
“It is important that children under 8 years of age receive 2 doses of the influenza vaccine in the same season if it is the first time they are being vaccinated.”
I would add that young babies also can be protected through breastfeeding because maternal antibodies can pass through the breast milk. In addition, other children in the home, fathers, grandparents, caretakers, and anyone else who is going to be around young children should be vaccinated to protect them. This also applies to any child with an underlying medical condition that results in a weakened immune system. Additionally, young children, especially those under 8 years of age, do not have as robust of an immune response to the influenza vaccine compared with older children and adults. For this reason, it is important that children under 8 years of age receive 2 doses of the influenza vaccine in the same season if it is the first time they are being vaccinated. It is also important to note in conversations with parents that influenza vaccines today are safer and less reactogenic than in years past. Children under 3 years of age traditionally have been given half the dose that is given to older children because the previous vaccines were more reactogenic (ie, children could develop fevers and local reactions with the full dose). However, these reactions are rarely seen with the vaccines we use today, and full doses can be given to all children, including those under 3 years old. It is also worth noting that using the LAIV is an option, per the most recent Centers for Disease Control and Prevention’s Advisory Committee on Immunization Practices recommendations. The LAIV is approved for use in children aged 2 years and older. Because it is a live attenuated vaccine, it is not appropriate for every child, but it is good to have options such as the LAIV for healthy patients who fall within the recommended profile. Providers should be current with annual updates in vaccine recommendations and knowledgeable about the different available vaccines for younger and older children.
Centers for Disease Control and Prevention. Children & influenza (flu). https://www.cdc.gov/flu/protect/children.htm. Accessed October 22, 2019.
Centers for Disease Control and Prevention. Live attenuated influenza vaccine [LAIV] (the nasal spray flu vaccine). https://www.cdc.gov/flu/prevent/nasalspray.htm. Accessed October 22, 2019.
Grohskopf LA, Alyanak E, Broder KR, Walter EB, Fry AM, Jernigan DB. Prevention and control of seasonal influenza with vaccines: recommendations of the Advisory Committee on Immunization Practices - United States, 2019-20 influenza season. MMWR Recomm Rep. 2019;68(3):1-21.
Mullooly JP, Bridges CB, Thompson WW, et al; Vaccine Safety Datalink Adult Working Group. Influenza- and RSV-associated hospitalizations among adults. Vaccine. 2007;25(5):846-855.