NurseWeek: Vaccines put to test before approval (Part III of a three-part series)

Vaccines put to test before approval
Part III of a three-part series

By Heidi Renner
Special to Health24News
September 11, 2000


	You've read the article. Now tell us what you think. Click here to see Part I of the series Click here to see Part II of the series Related sites National Vaccine Injury Compensation Program National Vaccine Information Center United States Public Health Service Advisory Committee on Immunization Practices Infectious Diseases Society of America American Academy of Pediatrics

Washington (H24N). While some parents are growing skeptical about the safety of childhood immunizations, they may not know how much testing a vaccine undergoes before being approved for use.

Years of testing and studies are conducted before a vaccine passes all the hurdles necessary to be approved. The latest example is the pneumococcal conjugate vaccine, which has been approved for all children 23 months of age and younger and for children 24 to 59 months of age who are at high risk of serious pneumococcal disease. Bruce Gellin, MD, executive director of the National Network for Immunization Information, said there are many ideas for vaccines, including vaccines for infectious diseases, cancer and auto-immune deficiencies. Not all the ideas are good, he says. Some don't work, and some are shown not to be viable in early studies. Most ideas don't get far.

Those that do show promise end up at the Food and Drug Administration (FDA). The FDA becomes involved when the testing starts to involve humans. If the testing shows progress, bigger tests are done. Before testing is done on children, it is done on adults. Then, if the vaccine is intended for infants, a small group of infants will be tested. This number increases as testing continues. Prevnar, the brand name for the pneumococcal vaccine, was given to 40,000 children in the process of testing, Gellin said.

Gellin said it's important to remember that all vaccines tested are automatically tested with all other vaccines. Any person receiving the new vaccine has already received the other approved vaccines. For example, Prevnar was not tested on any children who did not already have all of the other approved vaccines. Then comparisons can be made between two groups, those who have had the new vaccine plus all of the other vaccines and those who have had only the other vaccines and not the new one.

All of the information goes finally to an FDA advisory committee that decides two things: Is the vaccine safe, and does it work? After the advisory committee makes its recommendation, the FDA staff makes the final decision whether the vaccine may be marketed.

Once a vaccine is licensed, any physician may use it, but the next step is usually for groups such as the Centers for Disease Control and Prevention (CDC) and the American Academy of Pediatrics (AAP) to decide how it should be used in the general public.

Committees for the CDC and the AAP work independently but do usually iron out any difference before going public, Gellin said, to avoid confusion.

Barbara Fisher was a member of the FDA advisory committee that looked at the pneumococcal vaccine. She was the sole dissenting vote in the approval of the vaccine. She said the safety data were "questionable."

Fisher is also a co-founder of the National Vaccine Information Center, which encourages parents to make independent informed decisions about immunizations.

"It's one thing to make [the vaccine] available; it's another thing to require it for all children," Fisher said.

Fisher also points out that it is the FDA's responsibly to make sure each batch of a vaccine is safe.

Both the CDC advisory committee and the AAP have approved the pneumococcal vaccine.

Pneumococcal infections cause about 700 cases of meningitis, 17,000 cases of bloodstream infections and 200 deaths each year in children under the age of 5 in the United States.

Both committees voted that the vaccine should be given to infants at 2, 4, and 6 months, with a booster dose at 12-15 months old. Children who are unvaccinated and are 7 to 11 months old should be given a total of three doses, and children who are unvaccinated and are 12 to 23 months old should be given two doses, the committees decided.

Such recommendations come only after the committees weigh the immunization's health benefits against the risk it might cause a dangerous reaction. As promising as such newly approved vaccines may be to the professionals, Gellin realizes that perhaps the medical community is not getting the best information out to skeptical parents.