A statement released by US Food and Drug Administration (FDA) staff yesterday says that the new version of the nasal spray influenza vaccine, FluMist, appears to be effective for kids under 5 but is still under review by the advisory panel. The panel meets tomorrow to make its recommendations to the FDA.

FluMist is made by the American drug maker MedImmune Inc, which is being bought by AstraZeneca plc, a British company. MedImmune has submitted the vaccine for FDA approval for use in children under 5 who do not have a history of asthma or wheezing. The live attenuated flu vaccine is already approved for use with healthy 5 to 49 year olds.

MedImmune has conducted four clinical trials to assess the safety and efficacy of FluMist in children under the age of 5, including a large trial comparing FluMist with a trivalent inactivated vaccine (TIV). These studies concluded that FluMist is highly effective compared to TIV, and is also effective against Type A and B influenza.

Influenza is an important cause of illness and death in infants and young children. Children get the flu twice as often as adults. Reducing the infection rate in kids is not just beneficial for them, but also for the adults who catch it from them. In other words reducing childhood influenza has beneficial public health outcomes for all age groups.

In the United States immunization against flu is recommended for all children aged 6 months to 5 years, currently using injectable TIV. However, the level of protection offered by TIV is debatable, hence the search for more effective alternatives.

One result that is being considered by the safety panel, from trials not conducted by the manufacturer, is that the nasal spray caused more wheezing in children compared to those who only had the TIV version. However, the difference between the two groups was said to be small.

According to the FDA, the safety data includes evidence of other side effects, including pneumonia. In one study it reviewed, 3 per cent of the children between 6 and 12 months old who took the vaccine had to be taken into hospital with respiratory problems compared to only 1 per cent who had the TIV version.

Other side effects of FluMist include nasal congestion, runny nose, cough and sore throat.

MedImmune said, in their briefing paper submitted to the FDA last month that:

“The safety and efficacy of FluMist have been established for children 24 months through 59 months of age without a history of wheeze or asthma, and that the risk-benefit profile for children 12-23 months of age without a history of wheeze or asthma warrants use of FluMist in this population as well.”

A previous version of FluMist had to be kept in the freezer, but the newer version can be refrigerated.

Click here to view the 124 page briefing paper submitted to the FDA on FluMist (PDF reader required).

Click here for more information on Children and the Flu Vaccine from the US Centers for Disease Control and Prevention (CDC).

Written by: Catharine Paddock
Writer: Medical News Today