University researchers say the current Centers for Disease Control requirement for pediatric vaccine stockpiles is insufficient to cover average production interruptions.

The findings, published in Vaccine Journal, explain the current goal for stockpiles is to store six-months supply of pediatric vaccines. However, the research found that production interruptions are often longer.

The study investigated shortages of eight vaccines stockpiled in order to provide children with protection for infectious diseases. These range from hepatitis to mumps and measles.

From November 2000 to February 2004 there were six shortages of pediatric vaccines. Not one of those shortages was six months or less. The shortest was seven months, and the longest was 20.

The current $1 billion budget for stockpiles would provide about a six-month supply of the eight vaccines. The study instead recommends $1.5 billion, which would cover at least eight months to nine months, said Sheldon Jacobson, author of the study and professor in the mechanical and industrial engineering department.

“The key is that it would be a lot more protection for, considering what’s at risk, very little money,” Jacobson said.

Although the stockpiles were discussed some time ago, only recently have policymakers become concerned about them.

“The pediatric stockpiles were first thought of in 1983 so that if, for any reason, there was an interruption in production no child would go unvaccinated,” Jacobson said.

However, it was not until 2002, when a number of vaccine manufacturers had production problems that groups of nonimmunized children experienced small outbreaks, that stockpiles were given more thought, he said.

“Many of vaccines are for diseases that we just don’t see anymore,” Jacobson said, “But they are still dangerous to children.”

In the 1980s there were 20 major producers of the vaccines, said Ruben Proano, a study co-author and graduate student. That number has now shrunk to four producers. The reduced number of manufacturers plays a role in shortages, he said.

“Every part of production now is dependent on so many little things going well, that our findings are really not that surprising,” Proano said.

There have been no changes in policy since the study’s results were released, but Jacobson was happy just to have distributed the research to the public.

“The CDC has not responded to our findings, but there has been a tremendous amount of information promulgated from our Web site,” Jacobson said. “We just do the analysis and put out the information. The policymakers can make what they will of it.”

The Centers for Disease Control declined to comment.

The research grew out of interactions with the centers and was funded by the National Science Foundation.