UB researchers, led by Timothy Murphy, MD, could have a vaccine
against Moraxella catarrhalis ready for human testing in three to
five years.
University at Buffalo researchers will use a $1.6 million grant
from the National Institutes of
Health to develop the first vaccine against an understudied
bacterium that causes at least 10 percent of middle ear infections
in children.
Already, the scientists are testing several promising antigens
against Moraxella catarrhalis. A new vaccine could be ready for
human testing in three to five years, they say.
The UB scientists, who received the grant from the NIH’s
National
Institute on Deafness and Other Communication Disorders, are
among only a handful of researchers worldwide studying M.
catarrhalis.
To combat the organism, they’re identifying similar
antigens among all strains so a vaccine based on a single antigen
will protect against as many strains of the bacterium as
possible.
“Based on our results thus far, it looks like we will be
able to identify antigens that are identical or very similar among
all strains and genetic lineages,” says principal
investigator Timothy
F. Murphy, MD, SUNY Distinguished Professor of Medicine
and Microbiology and
Immunology.
The researchers are using bioinformatics to identify genes
predicted to encode proteins on the organism’s surface,
construct a gene chip to test which of the 300-plus possible genes
on the surface are identical or similar, and then clone genes for
some of the predicted proteins for testing in mouse models and in
vivo.
Originally considered a harmless bacterium, M. catarrhalis
causes milder cases of middle ear infections—or otitis
media—than other bacteria.
However, these infections are becoming more prevalent, perhaps
because existing vaccines against ear infections caused by other
bacteria are changing colonization patterns among otitis media
pathogens.
Of the 15 to 20 million annual cases of otitis media in the
U.S., about 10 percent are recurring.
“When a child has the infection, the middle ear fills with
fluid, a condition that can last for a month or longer,”
explains Murphy, senior associate dean for clinical and
translational research.
“During that time, the child’s hearing is muffled,
which disrupts the normal development of language and speech
skills, potentially resulting in long-term delays and learning
problems in school.”
Recurrent ear infections also require repeated courses of
antibiotics, which contribute to antibiotic resistance. Some
children must undergo insertion of drainage tubes under general
anesthesia.
A vaccine against M. catarrhalis may have implications beyond
middle ear infections, the researchers note: They hope it also can
be used to prevent infections in Chronic Obstructive Pulmonary
Disorder (COPD).
For more than a decade, Murphy, who directs UB’s Clinical and Translational
Research Center, has studied how M. catarrhalis causes both
type of infections.
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