Live Attenuated Influenza Vaccine: Looking Forward

Although live attenuated influenza vaccine (LAIV) was not recommended in the United States during the 2016-2017 season, interest in this product is very high because of its needle-free, easy administration. Pharmacists should note that public health officials in Canada and the European Union continue to recommend LAIV and did not take steps similar to those taken by the CDC.

The United States differs from other countries with regard to LAIV. In this country, LAIV's labeling includes a precaution about using this immunization in children younger than 5 years old who have asthma and concurrent recurrent wheezing. The precaution is based on pre-licensure clinical trials that suggested that this particular group might be at increased risk of wheezing after LAIV.

Researchers from the CDC have great interest in LAIV use in all patients, and expanding its use to children who have asthma. They continue to investigate this administration vehicle, and have published a study in the Annals of Allergy, Asthma, and Immunology indicating that children in the specific group do not seem to have an elevated risk for respiratory adverse events.

When children with asthma develop influenza, they are at higher risk for adverse events than other people. Any action that can increase influenza vaccine uptake in this group is warranted and welcome.

The research group followed people diagnosed with asthma in a population of 6.3 million using diagnosis codes and medical records. It included more than 12,000 people over 3 years (2008-2011) who received LAIV, three quarters of whom were children aged 2 to 17.

Patients who had asthma did not experience more respiratory adverse events than others. The researchers expanded the study to look at children aged 2 to 4 years old who had histories of recurrent wheezing, but no official asthma diagnosis. These children did not experience an increased rate of respiratory adverse events either.

The most commonly reported adverse events were rhinorrhea and nasal congestion. Vaccinated children with asthma were no more likely to develop upper respiratory tract infections or urticaria than others.

The researchers noted that in this particular study, uptake of influenza virus vaccine was higher than the national average. However, it was suboptimal. This is an area where pharmacists need to focus their attention and promote immunization.

Reference

Duffy J, Lewis M, Harrington T, et al; Vaccine Safety Datalink. Live attenuated influenza vaccine use and safety in children and adults with asthma. Ann Allergy Asthma Immunol. 2017;118(4):439-444.