Vaccine with University of Rochester roots saves thousands
from illness
A vaccine that had its start in basic research two decades ago at the
University of Rochester Medical Center has shown remarkable success, causing
rates of infection by a persistent microbe to plummet by 69 percent nationwide
in the span of just three years.
The success of the Prevnar vaccine, produced by Wyeth after the company
licensed basic technology from the university, is covered in the May 1 issue of
the New England Journal of Medicine. The numbers translate to roughly 20,000
fewer cases of infection each year in the United States, with the greatest
prevention among the youngest children.
Prevnar was introduced in 2000 to prevent invasive infections by pneumococcal
bacteria, which cause meningitis, ear infections, pneumonia, and other maladies
researchers say that in the developing world, about 1 million people die each
year of infections caused by the bacteria. The new study shows that the rate of
infection among children less than two years of age in seven cities around the
nation, including Rochester, fell 69 percent from 1998 to 2001. Surprisingly,
the rate of infection in unimmunized adults dropped as well, probably because
the vaccine eliminated or reduced the number of germs in children who normally
serve as reservoirs of Pneumococcus.
In Rochester, the effects were even more noteworthy: The vaccine slashed
infection in children under age 2 by 83 percent. Nancy Bennett, M.D., clinical
associate professor and deputy director of the Monroe County Health Department,
helped analyze the rates of infection in the Rochester area, along with project
coordinator Christine Long.
"The vaccine's real-world performance is remarkable," says Richard Insel,
M.D., the University of Rochester scientist who had a hand in creating the
technology more than two decades ago. The technology was created at what is now
the university's children's hospital, Golisano Children's Hospital at Strong.
"Of course the vaccine looked very good in the laboratory and in efficacy
field trials, but this is very, very good news under real-world conditions,"
says Insel, who notes the effectiveness of the vaccine despite periodic
shortages. "The data on decline in rates of invasive disease in adults, who were
not immunized, is fascinating as well. The vaccine seems to impose a type of
'herd immunity,' where the adults around these children are protected as well.
This is quite heartening."
Physicians at the university are currently conducting a study to see if
Prevnar is also effective in preventing pneumonia in elderly patients.
It was a team comprised of Insel, David Smith, M.D., and Porter Anderson,
Ph.D., that was one of the first to develop and test the concept of a
"conjugate" vaccine, a method to make a vaccine more effective by linking it to
a protein that would spur an infant's immune system to fight an infection
especially vigorously.
Insel, who is currently director of the university's Center for Human
Genetics and Molecular Pediatric Disease, and his colleagues showed that the
coupling of a protein to an existing polysaccharide vaccine evoked an immune
response in infants that could not be elicited with the plain polysaccharide
vaccine alone. The new Prevnar vaccine includes a mutant form of diphtheria
toxin that spurs the immune system to fight the Pneumococcus microbe
effectively.
Pneumococcus is the second microbe to be targeted by a "conjugate" vaccine
based on the Rochester technology. A decade earlier the team first used the
technology to take aim at a bacteria known as Haemophilus influenza type b
(Hib). After successful initial tests in the early 1980s, the team tried to
persuade a pharmaceutical firm to license the technology.
Vaccine research wasn't especially popular in the industry at the time, and
the offer was declined. So the group headed by Smith went into business together
and created a company, Praxis, to make the vaccine. The HIB vaccine was approved
by the Food and Drug Administration in 1990 at that time the first vaccine in
20 years to be recommended by FDA for universal use in children and has
virtually wiped out infection by the microbe, which was a leading cause of
meningitis in preschoolers. Illnesses caused by this disease in the United
States have fallen from 20,000 each year to about 200 cases since the
introduction of the HIB vaccine.
"The Haemophilus influenzae pathogen was the most common cause of meningitis
in children, as well as the most common cause of acquired mental retardation and
acquired deafness in children," says Insel. "During my training in the 1970s,
you could walk into any pediatric ward anytime and guarantee that there would be
at least one child with invasive Haemophilus influenzae. Now, there are so few
cases, a doctor will go years without ever seeing a case."
A third conjugate vaccine based on the technology, targeted against the
microbe meningococcus, is available in some parts of the world, including the
United Kingdom. This is the bacteria that causes spinal meningitis and
bloodstream infections that are extremely contagious and sometimes kill
previously healthy people very quickly.
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"A foolish faith in authority is the worst enemy of truth."
-- Albert Einstein, letter to a friend, 1901
"I know of no safe depository of the ultimate powers of the society but the people themselves, and if we think them not enlightened enough to exercise control with a wholesome discretion, the remedy is not to take it from them, but to inform their discretion by education."
-- Thomas Jefferson, letter to William C. Jarvis, September 28, 1820
"What's the point of vaccination if it doesn't protect you from the unvaccinated?"
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