By KRISTA CONGER

Despite last winter’s seemingly severe flu season, the influenza vaccine is regarded by many parents as an unnecessary and inconvenient intrusion.

In order to get full protection, children younger than age 9 need two doses, a month apart, for the first year they receive the vaccine. As for the newly available inhaled version of the vaccine, it’s not approved for use in children under 5.

During pediatric grand rounds Friday, David Lewis, MD, associate professor of pediatrics, and Kathleen Gutierrez, MD, assistant professor of pediatrics at Packard Children’s Hospital, covered key issues around recent influenza outbreaks, including the immunological basics of influenza infection and vaccination, the human cases of avian flu that have recently occurred in Vietnam and Thailand and the potential benefits of universal vaccination.

Gutierrez recommended that pediatricians remain alert to the possibility of human cases of avian flu occurring in children or adults who have recently traveled from Southeast Asia and urged them to remember to ask about potential contact with poultry or poultry droppings.

She also discussed the unusual features of this year’s human influenza A viral epidemic, which began, peaked and ended earlier than is typical.

Unfortunately, one of the influenza A strains used for both the injected and inhaled trivalent influenza vaccines was not well matched with the primary disease-causing strain and neither of these vaccines provided optimal protection.

Lewis discussed how the immune system normally eliminates influenza A from the body and reviewed the potential benefits of universal vaccination against influenza: Limiting dangerous medical complications in children and reducing the likelihood that infected children – who shed the virus at higher levels and for longer than adults – will spread the disease to other vulnerable people, such as the elderly.

It is possible that repeated priming of the immune system with known strains of influenza – as well as the development of new, more potent influenza vaccines – may at least partially protect against subsequently arising pandemic, or global epidemic, strains.

Finally, recent research by Lewis’s laboratory using a mouse model suggests that infection with influenza A may create risk factors to the later development of asthma and allergic disease.