New Flu Vaccine Recommendations From AAP

All children aged 6 months and older should receive an injectable influenza vaccine as soon as the vaccines become available, by the end of October, the American Academy of Pediatrics (AAP) says in a new policy statement.

The recommendations for the 2018-2019 influenza season follow a particularly severe season last year during which 179 children died from influenza-associated illness and thousands of children were hospitalized in the United States. Approximately 80% of the children who died were unvaccinated, according to the US Centers for Disease Control and Prevention (CDC).

The AAP published the recommendations online September 3 in Pediatrics.

"I can't emphasize enough the importance of everyone receiving the flu vaccine each and every year because it remains the best available preventive measure to protect against influenza," Henry Bernstein, DO, a member of the CDC Advisory Committee on Immunization Practices and an ex-officio member of the AAP Committee on Infectious Diseases, told Medscape Medical News.

"We really hope that people get vaccinated by the end of October, but if they don't, they can get the flu vaccine at any point throughout the season. It would be best to get it as soon as it's available in the community, because influenza virus is so unpredictable we never know whether the virus is going to be causing problems early on in the season — let's say in November before Thanksgiving — or whether it's going to be later on in the season in March or April. Although 80% of peak flu season comes in January, February, and March, that means 20% comes before and after those months," Bernstein explained.

New This Year

The AAP's first choice for immunization is an injectable form of the vaccine (inactivated influenza vaccine; IIV), which has consistently protected against all influenza virus strains in recent seasons. By contrast, the nasal spray vaccine, or live attenuated influenza vaccine (LAIV4), was less effective during the 2013-2014 and 2015-2016 seasons; therefore, it has not been recommended for the past two influenza seasons.

This season, the AAP says clinicians should offer the nasal spray vaccine to children who would otherwise not receive any influenza vaccine. These include children and parents who refuse an injectable flu vaccine or when a physician's office runs out of the injectable vaccines. It is not known how effective the latest nasal spray vaccine will be against the influenza A/H1N1 strain this season.

"The CDC has recommended it be offered like any of the inactivated flu shots; the AAP recommends the flu shot as the primary vaccine choice for all children," Bernstein said. "The AAP would rather children receive the nasal spray vaccine, as opposed to not receiving any vaccine at all."

The trivalent and quadrivalent injectable vaccines contain three and four influenza virus strains, respectively. The AAP does not recommend one injectable formulation over another.

For the 2018-2019 influenza season, the IIVs contain one new strain of influenza A (H3N2) and one new strain of influenza B (Victoria lineage). Seasonal influenza vaccine virus strains are selected each season based upon which viruses are circulating, the extent to which they are spreading and making people ill, and the effectiveness of the previous season's vaccine against those viruses.

"This is the first flu season during which we have several vaccine products and those are all flu shots that are licensed for children 6 months through 35 months of age. We used to only have one product and now there are two more on the market, so now we have three. There hopefully will be an adequate supply of vaccine available for children between 6 and 35 months of age," Bernstein said.

Additional Recommendations

A child's age and vaccine history determine the number of doses of influenza vaccine they require. Children aged 6 months through 8 years being vaccinated against influenza for the first time should receive two doses 4 weeks apart. Those aged 9 years and older need only one dose, regardless of their vaccination history.

The influenza vaccine may be administered to all children with an egg allergy of any severity, with no further precautions beyond those recommended for all immunizations. "That's important because in the past people had thought if you had egg allergy you couldn't receive the flu vaccine because it's made in egg, and the science does not support that," said Bernstein. "This should be emphasized because the recommendations have been evolving over the years; there have been a number of studies over the last 2 or 3 years that support this approach."

Vaccination of pregnant and postpartum women can protect infants who are too young to receive the influenza vaccine themselves. It is safe for mothers and infants when administered to pregnant, postpartum, and breastfeeding women. The influenza vaccine (IIV only) may be administered at any time during pregnancy.

"Pregnant women should receive the flu vaccine during pregnancy so that they protect themselves and pass their antibodies on to their newborn infant...The antibodies mom passes on to her newborn can help protect her young infant before he or she can receive his or her own flu vaccines beginning at 6 months," Bernstein explained.

Clinicians should encourage postpartum women not vaccinated during pregnancy to receive an influenza vaccine before they are discharged from the hospital.

The AAP recommends vaccination of all healthcare workers because they frequently care for individuals at high risk for influenza-associated complications. Household contacts and out-of-home childcare providers of children younger than 5 years and children of all ages who are at risk, as well as close contacts of those with immunosuppression, should also receive the influenza vaccine.

Moreover, the AAP recommends that clinicians should try to quickly identify suspected influenza in their patients so antiviral treatment can be given when appropriate, after shared decision-making between clinician and child caregiver. Antiviral treatment is most effective when administered within 48 hours of symptom onset; however, clinicians should still consider giving it after that time in severely ill children or those at high risk for complications. Antiviral treatment is not a substitute for vaccination, the AAP warns.

“Staying healthy is the goal for all of us. As a pediatrician and mom, I see too often how quickly the flu spreads,” Wendy Sue Swanson, MD, a pediatrician in Seattle and an AAP spokesperson, said in a news release. “Unfortunately, you can spread influenza without realizing it because some infected people begin to spread the virus a day or two before they have symptoms. Get the shot. It just makes sense.”

The authors and Bernstein have disclosed no relevant financial relationships.

Pediatrics. Published online September 3, 2018. Abstract

For more news, join us on Facebook and Twitter