Study Shows Kids Vaccine Reaction Similar

WASHINGTON -- Thousands of children immunized with a new vaccine to prevent pneumococcal infections such as meningitis and pneumonia suffered fever, fussiness, rashes, seizures and 117 died -- but the bulk of the reactions likely had nothing to do with the vaccine Prevnar, researchers reported Tuesday.

The research team said the reactions were similar to those seen with other vaccines.

The rashes, crying and fussiness, breathing difficulties, and stomach upset reported are "common childhood symptoms apart fromimmunizations," the researchers wrote in the Journal of the American Medical Association.

Serious events, including seizures, allergic reactions and abnormally low counts of platelets, a kind of blood cell, were rare, the researchers said.

"We know that Prevnar is a very safe and very effective vaccine," Dr. Robert P. Wise, acting head of the Food and Drug Administration's therapeutic and blood safety branch, and lead author of the report, said in an interview.

The team looked for red flags in a database that would have revealed worrisome safety trends with Prevnar, but found none.

"It's not pointing to anything," agreed Dr. Paul A. Offit, chief of Infectious Diseases at the Children's Hospital of Philadelphia and an expert on vaccine safety who was not involved in the research. "That's good. It makes biological sense."

The vaccine is a complex sugar hitched to a harmless protein and should be safe, Offit said.

The FDA cleared the seven-valent pneumococcal conjugate vaccine for use on Feb. 17, 2000. It has rapidly become a routine shot that pediatricians give in tandem with other childhood vaccinations. An earlier study in JAMA attributed to the vaccine's use a drop in childhood pneumonia and meningitis, more common among blacks than whites.

In the first two years after the vaccine was used widely, researchers found 4,154 adverse events -- among 31.5 million vaccine doses -- had been reported to a national database. That amounts to 13.2 reports for every 100,000 doses of vaccine distributed. The majority of the time, children received multiple vaccine shots in a single setting.

Most complaints were minor -- fever, swelling at the injection site, fussiness and rashes -- and had been seen in earlier clinical trials. The 608 more serious events included 117 deaths and 34 instances in which children suffered invasive pneumococcal infections, hinting at vaccine failure.

The FDA was concerned about seizures, since clinical trials before the drug was approved for use suggested a higher risk for such neurological symptoms.

In the first two years of use, 393 seizures were reported. The research team followed up on the first 98 seizure reports.

The vast majority were fever-related seizures or events in children with a previous history of seizures, the authors wrote. Vaccination may have played a role "in at least some" seizures. "Like other vaccines, (Prevnar) can provoke fever, which could trigger a febrile seizure," they wrote.

Wise said the single most important finding for parents was 14 cases of serious allergic reaction days after Prevnar vaccination. Medical attention was speedy and no child died. Such severe allergies can occur with any vaccine, Wise said. In the Prevnar reports, one ultimately was tied to infant formula.

"Many of the adverse events that get reported after vaccinations are probably due to causes other than the vaccine," he said. "You have to be quite cautious in interpreting data from these spontaneous reports."

He said the agency's continued monitoring will keep close tabs on adverse events that follow repeated vaccination. Children receive multiple doses of Prevnar with catch-up doses suggested through age 9.

Having lowered platelet counts and severe allergic reactions after repeat vaccinations heightens suspicion that the vaccine is responsible, said Dr. Martin Myers, director of the National Network for Immunization Information. "That adds more emphasis it might be cause and effect."

The research team pointed to other limitations in the national database, since many ailments are underreported and, in the face of unexplained deaths, people are more apt to blame a new medication.

Still, the Vaccine Adverse Event Reporting System raised an early red flag associating a different vaccine to a condition in which the lining of the bowel folds, causing a blockage. The early warning triggered follow-up studies that confirmed the vaccine link.

The vaccine manufacturer is completing a lengthy study that tracks 155,000 children in California. The group includes children immunized as early as 1995. So far, no serious safety concerns have cropped up among that larger group either, said Peter Paradiso, Wyeth vice president of scientific affairs.

Knowing Prevnar -- like other vaccines -- can lead to fever gives parents a chance to be pro-active, said Dr. Sharon G. Humiston, an associate professor of emergency medicine and pediatrics at the University of Rochester Medical Center.

Parents of children known to suffer febrile seizures should consider ibuprofen with the vaccine. "Unlike the timing of fever from illness, which is unpredictable, fever from vaccination is predictable," Humiston said.