Universal vaccination associated with decreased Canadian cases of most deadly strain of meningitis

[Guest guest]

http://www.eurekalert.org/pub_releases/2009-03/cfr-uva030209.php

Universal vaccination associated with decreased Canadian cases of most

deadly strain of meningitis

Canadian infants now routinely immunized with meningococcal C vaccine

Universal childhood vaccination against meningococcal C appears to reduce

Canadian incidence of the most deadly strain of bacterial meningitis,

reports new research published in the March issue of The Pediatric

Infectious Disease Journal.

The Men C vaccine was introduced as part of universal immunization programs

for children in Quebec and Alberta in 2002 and in British Columbia and

Prince Island in 2003.

By 2005, all Canadian provinces included Men C vaccine as part of routine

childhood vaccinations. Staggered implementation across Canada offered

researchers the opportunity to evaluate the universal vaccination program.

" There was a dramatic decline in provinces with the early immunization

program, suggesting the program works, " says Dr. Bettinger, the study

s lead author.

Dr. Bettinger is a scientist in the Vaccine Evaluation Centre at the Child &

Family Research Institute and assistant professor in the Department of

Pediatrics at the University of British Columbia.

Prior to Men C universal vaccination, BC, Alberta, and Quebec had rates of

meningococcal C disease that were nearly 4.5 times higher than the rest of

Canada. The study reports that today these provinces have the lowest rates

in Canada, from 0.41 cases per 100,000 people in 2002 down to 0.07 per 100

000 in 2006. The provinces with later introduction of universal Men C

vaccination showed no major changes in the one year of follow up study, with

annual rates of meningococcal C at 0.08 per 100,000 people in 2006.

" The numbers may seem small, but even one case of the disease is one too

many, " says Dr. Bettinger. " It can strike without warning and cause death or

permanent physical or neurological disability. Because meningococcal

infection is spread by saliva through coughing, sneezing, and kissing, it

has the potential to become an epidemic. Universal vaccination is critical

to control disease and prevent epidemics. "

Meningitis is an infection of the lining that covers the brain and spinal

cord. It can be caused by viruses and bacteria. The viral causes of

meningitis are rarely life-threatening whereas the bacterial types are more

deadly. There are five strains of meningitis caused by the meningococcal

bacteria (called serogroups A, B, C, Y, and W135). Meningococcal vaccines

protect against A, C, Y, W135 with the Men C public vaccination programs

targeting the meningococcal C bacteria. The researchers did not observe

significant changes in the rates of other strains causing meningitis

following introduction of the meningococcal C vaccination program.

Infection with the meningococcal bacteria develops suddenly into a medical

emergency that must be treated in hospital with IV antibiotics. Initial

symptoms include fever, headache, stiff neck, vomiting, and drowsiness while

in infants it may show as irritability and lethargy. It can cause gangrene

leading to amputation of limbs, blindness, deafness, brain damage, and

cognitive and neurological disability. Children, adolescents, and

immuno-compromised individuals are most vulnerable to infection.

Meningococcal C is the most fatal strain of bacterial meningitis. It infects

approximately 250 Canadian children and adults each year, according to the

BC Centre for Disease Control. For every 100 children who get sick, up to 15

will die. Those who survive may face life-long disability.

The Men C vaccine is provided free to all children in BC along with the

regular childhood vaccinations. Infants need two doses: one needle at two

months of age and then another at 12 months. The vaccine is also provided to

people who may be vulnerable because they are missing a spleen, they have a

weak immune system, are transplant recipients, or they have a cochlear

(inner ear) implant.

The Men C vaccine is the first product suitable for infants offering

long-term immunity against meningococcal C and it became commercially

available in 2001. Previously, adolescents or adults received a different

vaccine which provided protection for about three years.

For the study, the 12 pediatric centres involved with the Canadian

Immunization Monitoring Program, Active (IMPACT), carried out surveillance

in collaboration with local public health officials. IMPACT meningococcal

surveillance is administered by the Canadian Paediatric Society and funded

by Sanofi Pasteur. Its surveillance centres are located in Newfoundland,

Nova Scotia, Quebec, Ontario, Manitoba, Saskatchewan, Alberta, and BC.

" What's needed next is a vaccine against meningococcal B, " says Dr. Bettinger.

" This is the Holy Grail of vaccine research. "