Kids' vaccine slashes meningitis

[AlaskaDenise]

We've had posts about this vaccine before, but this is an update of the situation.
----------------------------------------------------------------------------
Meningitis cases have fallen sharply since the introduction of a vaccine for children in 2000, a new study shows.

Rates of pneumococcal meningitis, an inflammation of the membranes around the brain caused by bacteria, dropped 64% in children under age 2 from 1998-1999 to 2004-2005, according to a study in today's New England Journal of Medicine. The Centers for Disease Control and Prevention recommends the vaccine for children ages 2 months to 2 years, and for 2- to 5-year-olds who are at increased risk.

The vaccine hasn't just helped children, though.

With fewer contagious babies to spread germs, fewer older kids and adults are getting sick, says co-author Nancy Bennett, a professor at the University of Rochester School of Medicine and Dentistry. Episodes of pneumococcal meningitis dropped 30% in the overall population, falling from 1.13 cases per 100,000 people to 0.79 cases per 100,000 people.

Even more impressively, cases dropped 54% in people over 65, Bennett says.

This kind of "herd immunity" ? in which vaccines protect even unvaccinated people ? is especially important in the elderly, Bennett says, because youngsters can spread the bacteria that cause meningitis in their grandparents. And this kind of meningitis is even more lethal in adults than children. In her study, one in 12 children died from their meningitis, compared with one in five adults.

Doctors already had noticed that the vaccine has reduced other diseases caused by the pneumoccocal bacteria, such as blood infections, says Janet Englund, a member of the CDC's vaccine committee and a pediatrician at Seattle Children's Hospital, who was not involved in the study.

As with all vaccines, doctors don't yet know how long its immunity will last, Bennett says.

Englund says the paper also spotlights a troubling trend: The kinds of bacteria that cause meningitis are changing.

The shot, called Prevnar, protects against seven strains of pneumococcal bacteria. But other strains not included in the current vaccine ? including some that can't be killed by standard antibiotics ? are now increasing, the study shows. Englund says doctors today are already on guard for resistant bacteria, though, and often treat patients with two antibiotics.

The number of meningitis cases due to these resistant bacteria is very small compared with the large number of cases that the vaccine prevents, Bennett says. Researchers are already developing vaccines to protect against up to 13 strains of the bacteria.

http://www.usatoday.com/news/health/2009-01-14-prevnar-meningitis_N.htm

 

[AlaskaDenise]

Re: Kids' vaccine slashes meningitis

Meningitis Vaccine Seems to Work Like a Charm
Study finds it has led to a considerable reduction in infection rates

Posted January 14, 2009
By Amanda Gardner
HealthDay Reporter

WEDNESDAY, Jan. 14 (HealthDay News) -- Rates of pneumococcal meningitis, a potentially life-threatening infection, have declined substantially since a new vaccine was introduced in 2000, a new study shows.

The declines have been seen not only in children given the vaccine but also in adults, suggesting a herd immunity effect, the researchers noted. To assess the effect of the vaccine, researchers from several universities analyzed surveillance data from 1998 to 2005 in eight states.

Overall, the number of cases of the disease dropped 30 percent in that time, but the effect on the very youngest and oldest was even more pronounced: Incidence decreased by 64 percent in those younger than 2 and by 54 percent in those older than 65.

"This vaccine has really had a very profound effect on the incidence of pneumococcal disease," said study co-author Dr. Nancy Bennett, a professor of medicine at the University of Rochester Medical Center, in New York. The report appears in the Jan. 15 issue of the New England Journal of Medicine.

The study goes beyond previous research in terms of looking at population groups as well as different forms of Streptococcus pneumoniae, which causes pneumococcal meningitis, an inflammation of the meninges, or membranes, surrounding the brain and spinal cord.

"This is a pretty comprehensive study looking at a number of different serotypes [groupings of bacteria within a family] and all age groups. It gets a nice survey of the population," said Jeffrey Cirillo, an associate professor of microbial and molecular pathogenesis at Texas A&M Health Science Center College of Medicine, in College Station. "It is only in eight states so it's not throughout the entire country, but it's probably the most comprehensive analysis, and no one else had looked at it over that long of a period."

The vaccine, known as Prevnar and made by Wyeth Pharmaceuticals, is part of the standard vaccination recommendation for children in the United States ages 2 to 23 months, as well as for children 24 to 59 months old who are at high risk for pneumococcal disease.

Since the vaccine came out in 2000, there have been a number of studies reporting on its effect on meningitis and blood infections.

"This is the first to focus specifically on meningitis," Bennett said.

There was a 73.3 percent decrease in the incidence of PCV7 serotype (bacteria types covered by the vaccine) in all age groups. Researchers [/B]also found declines in antibiotic-resistant serotypes not specifically targeted by the vaccine[/B] ????.

"There were small increases in the rates of meningitis caused by serotypes that are not included in the vaccine," Bennett noted. The study reported a 60.5 percent increase in cases of meningitis types not protected by the vaccine, but Bennett said that "even a 60 percent increase in something that doesn't happen much has a small effect overall."

The increases were "outweighed by the overall decrease in disease," she said.

However, she continued, "it is something that we need to closely observe and that will be addressed with vaccines that cover more serotypes."

Prevnar was developed by researchers at the University of Rochester, who sold the technology to Wyeth, according to a university spokesman. Several authors of the study, including Bennett, have received funding from Wyeth and other pharmaceutical companies.

Cirillo described the study results as "very promising."

"This is a pretty significant finding, especially the large impacts the vaccine has on serotypes it covers," he said. "And within the serotypes that were covered, the efficacy was up to about 90 percent," referring to certain groups that showed the incidence of pneumococcal meningitis decreasing by almost 93 percent. That's amazing."

http://health.usnews.com/articles/h...gitis-vaccine-seems-to-work-like-a-charm.html

 

[AlaskaDenise]

Re: Kids' vaccine slashes meningitis

Germs Flourish When Not on Target for Wyeth?s Meningitis Shot


By Tom Randall

Jan. 15 (Bloomberg) -- Wyeth?s Prevnar vaccine has proven so effective against the meningitis-bacteria it targets that competing strains are flourishing in the throats of children, researchers found.

Prevnar is designed to prevent 7 of 90 strains of pneumococcal bacteria, a leading cause of pneumonia and meningitis, a rare and deadly brain infection. Strains of meningitis not targeted by the vaccine increased 61 percent since the shot was introduced almost a decade ago to 1 case in every 200,000 people, according to the study funded by the U.S. Centers for Disease Control and Prevention and published yesterday by the New England Journal of Medicine.

Overall cases of meningitis fell 30 percent, according to the study. Prevnar helped prevent more than 60,000 life- threatening bacterial infections in U.S. children younger than 5 since its approval in 2000, the Atlanta-based CDC said in February.

?This is a great vaccine and we should continue to use it to the max,? said Lee Harrison, senior author of the study and a professor of medicine and epidemiology at the University of Pittsburgh and adjunct professor of health at the Johns Hopkins Bloomberg School of Public Health in Baltimore. ?But if you immunize kids, they?re less likely to acquire the vaccine strains, and it basically creates a niche for non-vaccine strains to fill.?

$2.4 Billion

Prevnar is the Madison, New Jersey-based drugmaker?s second- biggest drug, with $2.4 billion in global sales in 2007. Wyeth plans to seek U.S. approval this year for a new vaccine that would cover six additional strains, including those responsible for half the infections reported in the study that Prevnar didn?t target.

Pneumococcal bacteria cause pneumonia when they get into the lungs and meningitis if they reach the brain. Diseases brought on by these bacteria are the world?s top vaccine-preventable killers of young children. Many strains that flourish in the absence of those targeted by Prevnar are harmless, while others can lead to infections and life-threatening meningitis, the study said.

Children help spread the bacteria to adults. Vaccination programs for the young also protect the elderly, who have lower vaccination rates. Meningitis cases among adults ages 65 and older fell by 54 percent according to the study, showing ?enormous benefit? of childhood vaccinations even in people who haven?t been inoculated, Harrison said in a telephone interview.

?If you go out to a shopping mall, and you do a throat swab of 100 kids, you?ll find about a third of them carry the organisms in the back of the throat,? Harrison said. ?Most of them cause no problem, but some of the strains are capable of causing serious disease.?

To contact the reporter on this story: Tom Randall in New York at trandall6@bloomberg.net.

Last Updated: January 15, 2009 00:01 EST
http://www.bloomberg.com/apps/news?pid=20601103&sid=aTtUUBxE9oQg&refer=us#