Company Is Investigating Possible Vaccine Problems in Brazil
Company Is Investigating Possible Vaccine Problems in Brazil
By LAWRENCE K. ALTMAN
Published: August 28, 2004
Source: New York Times
A day after the Chiron Corporation said it was delaying release of its influenza vaccine in this country because some lots were contaminated, the company confirmed that it was investigating possible problems with use of a different vaccine in Brazil.
Brazilian health officials stopped the use of Chiron's triple vaccine against measles, mumps and rubella, often referred to as MMR, after an unexpectedly high number of children who received it experienced serious allergic reactions in an immunization program last week. The reactions included rashes and anaphylactic shock, a potentially fatal allergic condition. There were no deaths reported.
Chiron and Brazilian health officials are investigating the cases of at least 125 children who experienced the reactions.
The vaccine problems raise concern because Chiron, the world's fifth-largest vaccine manufacturer, is under contract with the United States government to produce pilot supplies of human vaccines against two strains of avian influenza, which has spread widely in Asia. The pilot vaccines are needed because health officials around the world have expressed fears that in a worst-case scenario, the avian strains could mutate to cause a human pandemic.
The rates of adverse reactions were significantly higher among the children receiving the Chiron vaccine, which is made in Italy, than among children who received a vaccine made by another company, the Brazilian representative of the Pan American Health Organization said. The organization, part of the World Health Organization, supplies the vaccine.
"But the situation remains unclear," said a spokeswoman for Chiron, Alison Marquiss, because full information was not available to determine whether the reactions were due to the vaccine, to monitoring or to other issues.
Chiron's vaccine against the three childhood diseases is sold in Italy, Asia and South America, but not in the United States, said Ms. Marquiss. She said the episode in Brazil was the first time any problems had been reported from Chiron's MMR vaccine.
Although a link between Chiron's vaccine and the reactions has not been proved, Ms. Marquiss said that "generally speaking, when a vaccine is quarantined in this fashion it is unlikely to return to the Brazilian market."
In recent years, health officials in the United States and elsewhere have had to deal with delays in distributing influenza vaccines and shortages in the amount that could be manufactured because of production problems.
Safety tests of the pilot human avian flu vaccines are expected to begin in this country next winter, said Dr. Anthony S. Fauci, the director of the National Institute of Allergy and Infectious Diseases, the federal agency in Bethesda, Md. It has contracted with Chiron, which is based in Emeryville, Calif., and another company, Aventis, for the pilot vaccines.
Making vaccines "is a very tenuous field and these kinds of things come up all the time," Dr. Fauci said.
How the company involved responds in such situations is crucial, Dr. Fauci said, adding that he believes Chiron "is one of the groups that can respond" because they are forthcoming and have the technological and scientific skills to overcome such obstacles.