CLEMSON — Optimal control of the spread of the seasonal flu and H1N1 is achieved by prioritizing vaccinations for schoolchildren and for adults aged 30 to 39 in the United States. Those are the findings of a new study by Clemson University mathematician Jan Medlock and colleague Alison Galvani of the Yale University School of Medicine.
The researchers have developed models that challenge the recommendations of the Centers of Disease Control and its Advisory Committee on Immunization Practices for which segment of the population should be vaccinated against the flu. In their findings, published Aug. 20 in Science Express http://www.sciencexpress.org, the researchers say the U.S. population can be best protected by stopping the high levels of transmission among schoolchildren and to their parents, despite the fact that other age groups may suffer more severe symptoms if they catch the flu.
“Current flu vaccination recommendations include children under age 5 and for seasonal flu, people over age 50,” said Medlock. “The vaccines would be better used to prevent transmission within schools and out to parents, who then spread the flu to the rest of the population. The CDC recommendations have been changing the last few years, particularly due to the new H1N1 strain, and have been moving in the right direction.”
The researchers studied mortality data from the United States and survey-based data on infectious contacts from the influenza pandemics of 1918 and 1957, taking into consideration multiple ways to quantify the impact of an influenza outbreak: deaths, infections and other measures that vary with the age of those infected. Strikingly, they found that all the measures led to the conclusion that schoolchildren and their parents are the best groups to vaccinate when even a modest amount of an effective vaccine is available.
The World Health Organization has announced the possibility of shortfalls in the production of H1N1 vaccines this year due to the slow growth of the swine-origin H1N1 in chicken eggs. The researchers concluded that when vaccine availability is limited or when vaccine efficacy is low, optimal allocation of vaccines is imperative to minimize the spread of the illness.
The research was funded with a $650,000 grant from the National Science Foundation.