Four child deaths in three days has forced Japan’s health ministry to suspend pediatric vaccines made by Pfizer after reports of four deaths following immunizations using the brand name Prevenar. The deaths of the children occurred from March 2 to March 4, the ministry said. Prevenar was approved by the U.S. Food and Drug Administration for immediate release to the public on February 24, 2010.

ActHIB was given to three of the four children, who were simultaneously vaccinated with at least one other vaccine from a different manufacturer. Haemophilus influenzae type b (Hib) caused 2 million to 3 million cases of serious disease, notably pneumonia and meningitis, and 386,000 deaths in young children in 2000, according to the Geneva-based World Health Organization.

The use of Pfizer’s Prevenar is used against common types of Streptococcus pneumoniae bacteria. These bacteria are responsible for causing invasive diseases such as pneumonia, blood poisoning and meningitis. The vaccine works by provoking the body’s immune response to the bacteria, without causing the diseases.

When the body is exposed to foreign organisms, such as bacteria and viruses, the immune system produces antibodies against them. Antibodies help the body recognize and kill the foreign organisms. They then remain in the body to help protect the body against future infections with the same organism. This is known as active immunity.

Prevenar contains inactivated extracts from thirteen of the most common types of Streptococcus pneumoniae bacteria. It stimulates the immune system to produce antibodies against these bacteria and is given to prevent the diseases that they can cause.

In a statement, Pfizer said:

“Pfizer thoroughly reviews and continually monitors all of its medicines and vaccines as safety is our top priority. The company thoroughly evaluates all reported cases and works closely with health authorities to determine if there is any association with use of our medicines and vaccines.”

A Japanese safety panel will meet March 8th to discuss the cause of the deaths. About 1.5 million Japanese children have received ActHIB since it was approved in Japan in 2007, 15 years after it was first licensed in Europe. In the early 1980s, an estimated 20,000 HIB cases occurred each year in the United States, mostly among children under 5 years of age. With the introduction of Hib vaccine in 1987, the number of Hib cases began to drop and has declined by more than 99% compared with the pre-vaccine era.

Victor Carey, the Sydney-based Asia Pacific medical director for Sanofi’s vaccines unit adds:

“No causal relationship has been established between immunization and these fatalities, but an investigation is under way, which we’re fully cooperating with.”

The vaccine that protects against 13 serotypes generated $2.42 billion last year and a shot that fights seven serotypes had $1.25 billion in 2010 sales. More than 200 million doses of ActHIB have been given to children in more than 120 countries, according to Paris-based Sanofi.

In 2001, the Centers for Disease Control (CDC), upon advice from its Advisory Committee on Immunization Practices, recommended the vaccine be administered to every infant and young child in the US. The resulting demand outstripped production, creating shortages not resolved until 2004. All children, according to current US vaccination schedules, should receive four doses, at two months, four months, six months, and again between one year and fifteen months of age.

Source: HKSAR Government News Release

Written by Sy Kraft, B.A.