Company Is Investigating Possible Vaccine Problems in Brazil


Published: August 28, 2004

Aday 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.