Immunization against viral respiratory disease: a review

Healthy and at risk children are susceptible to the morbidity and mortality associated with viral-induced respiratory diseases, including respiratory syncytial virus (RSV) and influenza. The World Health Organization is attempting to develop and distribute effective vaccines to prevent/reduce key viral respiratory diseases.

The goals of a vaccination program for viral respiratory infections include the prevention of lower respiratory tract infections and prevention of infection-associated morbidities, hospitalization and mortality. This article explores influenza and RSV vaccine developments.

There are 2 influenza vaccines, trivalent inactivated and live, cold-adapted, attenuated. Trivalent inactivated vaccine is indicated for persons older than 6 months of age. Currently <10%, <30% and <30% of healthy children, healthy adults and high risk children, respectively, are vaccinated. Efficacy is from 70 to 90% in healthy adults younger than 65 years of age and 30-90% in children, with lower efficacy in younger children. Live, cold-adapted, attenuated vaccine is indicated for healthy persons 5-49 years of age and usually is 70-90% effective. Various RSV vaccine formulations are being investigated. The Advisory Committee on Immunization Practices (ACIP) recommends influenza vaccination for children 6-23 months old. Studies support immunization of all children, not only those at high risk. Current ACIP recommendations focus on high risk persons and do not include school age children. A universal immunization program for all children could benefit the entire community.

Effective vaccines are available for some viral respiratory pathogens (eg, influenza virus), but not for most mucosally restricted respiratory viral pathogens. Research should continue into safe and effective vaccines for all childhood viral illnesses.