| Experts confident vaccine is safe 04/09/2001 By Sherry Jacobson / The Dallas Morning News While Prevnar's safety remains controversial to some consumer groups, few medical experts are concerned.
In the year that the vaccine has been on the market, 13.2million doses have been distributed nationwide. And the federal government's vaccine surveillance system has found no major problems.
"There is no evidence that anything is going on with Prevnar that is either serious or unexpected," said Dr. Ben Schwartz, a vaccine surveillance expert with the National Immunization Program at the U.S. Centers for Disease Control and Prevention.
But the National Vaccine Awareness Information Center, a Virginia-based group advocating major changes in national vaccination practices, is unconvinced. "Our children are the guinea pigs, and we will see what happens in a few years," the center predicts. A "critical review" of Prevnar, posted on the center's Web site (www.access1.net/via), contends that the vaccine hasn't been adequately tested and that it may interfere with other vaccines. Without further research, the center argues, scientists cannot know whether it will cause chronic diseases in the future.
Prevnar, manufactured by the Lederle Laboratories Division of the American Cyanamid Co., has been shown to protect children against the most serious side effects of pneumococcal disease, a bacterial infection that causes more than 7million ear infections in American children each year. Clinical trials found that the vaccine nearly eradicated the risk of pneumococcal meningitis and reduced the number of cases of pneumonia and blood infections in children who received a four-dose regimen starting at 6 weeks old.
Dr. Jane Siegel, who served on a national advisory committee that last year recommended approval of Prevnar, said it was endorsed only after research showed conclusively that it was safe and effective.
"Even those children who received only one dose of Prevnar got some protection from the more serious complications of pneumococcal infection," said Dr. Siegel, a professor of pediatrics at the University of Texas Southwestern Medical Center at Dallas and a pediatric infectious-disease specialist.
If Prevnar were causing serious complications, it would be obvious by now, and the government would have responded, Dr. Schwartz said. As an example, he recalled how the federal government withdrew RotaShield, an anti-diarrhea vaccine, after reports two years ago of serious complications in 20 children.
"We knew after 1.5million doses [of RotaShield] that there might be something going on with bowel obstructions," he said. "We stopped the vaccine, did further studies and, indeed, found something."
So far with Prevnar, the government has received about 1,300 reports of "adverse events," stemming from the vaccination of more than 5million children, Dr. Schwartz said. Doctors and hospitals are required to report such incidents to the Vaccine Adverse Event Reporting System, which is run jointly by the CDC and the U.S. Food and Drug Administration. Congress established the system in 1986 to ensure the ongoing safety of mass immunization efforts.
Dr. Schwartz said that 85percent of these reports of adverse events – including slight fever, vomiting, diarrhea and rash or hives – were minor, brief and within the scope of the side effects seen in the clinical trials. About 15percent of the reports alleged more serious complications caused by the new vaccine. However, the government found no connection between those adverse events and Prevnar, Dr. Schwartz said.
"Events will occur after vaccination that are not caused by the vaccine," he noted. Children can have seizures, for instance, within days of vaccination without the two events being related.
"It's important to investigate each case, but it's also important to look for patterns. There is no pattern, no suggestion and no red flag that there is a problem with this vaccine." |
