Wyeth Vaccine Significantly Reduces Meningitis Rates

Vaccinations, while somewhat controversial, have proven to save lives and now we can add one more to the ever-growing list of injections. The pneumococcal meningitis vaccine, introduced in 2000, has show to have significant protection against the life-threatening inflammation of the membranes surrounding the brain and spinal cord.

According to a recent study, a standard childhood vaccine administered for the prevention of a number of common infections has proven beneficial in reducing the rate of infection for this deadly form of meningitis. The number of infections has declined by 30 percent in children and adults. The fact that adults have indirectly benefited from the vaccine suggests the occurrence of an effect known herd immunity, in which vaccines protect even unvaccinated people.

Researchers analyzed observation data from eights states, covering the period from 1998 to 2005. Although the overall decline of the disease was shown at a rate of 30 percent, a decrease of 64 percent was seen in children younger than two years along with a 54 percent decrease in the elderly beyond age 65.

The study is the most comprehensive analysis to date, covering a seven-year span of time. The report was published in the New England Journal of Medicine. According to study co-author Dr. Nancy Bennett, a professor of medicine at the University of Rochester Medical Center in New York, “This vaccine has really had a very profound effect on the incidence of pneumococcal disease.”

The vaccine, known as Prevnar, is made by Wyeth Pharmaceuticals. The Centers For Disease Control (CDC) recommend Prevnar as a standard vaccination for children between the ages of two to 23 months, as well as for those children between the ages of 24 to 59 months having a high risk for contracting pneumococcal disease. The vaccine provides protection against seven common strains of Streptococcus pneumoniae, also called pneumococcal bacteria that account for over 80 percent of pneumococcal disease in children. These bacteria cause conditions such as ear infections, meningitis and pneumonia as well as blood infections.

Other results showed an overall 73.3 percent decrease in bacteria types covered by the vaccine (serotypes) as well as in antibiotic-resistant serotypes not targeted by the vaccine. However, it must be noted that the study also revealed an increase of pneumococcal meningitis in strains not covered by the vaccine and as well as those resistant to antibiotics. The non-PCV7 strains of meningitis were shown to have increased by 60.5 percent from 1998-99 to 2004-2005 and strains not sensitive to penicillin have risen to 30.1 percent in 2005 compared to 19.4 percent in 2003.

According to Bennett, the increases were “outweighed by the overall decrease in disease.” Yet, she also noted, “It is something that we need to closely observe and that will be addressed with vaccines that cover more serotypes.”

According to a university spokesperson, Prevnar was originally developed by researchers at the University of Rochester, who later sold the technology to Wyeth. Wyeth is now testing an extended version of the vaccine that will cover 13 strains of pneumococcal bacteria with plans to request U.S. regulatory approval within the first quarter of this year.