Lauri A. Hicks talks with
ScienceWatch.com and answers a few questions about
this month's New Hot Paper in the field of
Immunology.
Article Title: Incidence of pneumococcal disease
due to non-pneumococcal conjugate vaccine (PCV7) serotypes
in the united states during the era of widespread PCV7
vaccination, 1998-2004
Authors: Hicks,
LA;Harrison, LH;Flannery, B;Hadler, JL;Schaffner,
W;Craig, AS;Jackson, D;Thomas, A;Beall, B;Lynfield,
R;Reingold, A;Farley, MM;Whitney, CG;Active Bacterial Core
Surveillance
Journal: J INFEC DIS, Volume: 196, Issue: 9, Page:
1346-1354
Year: NOV 1 2007
* 1600 Clifton Rd,Mailstop C-23, Atlanta, GA 30333
USA.
* Ctr Dis Control & Prevent, Resp Dis Branch, Atlanta,
GA USA.
(addresses have been truncated)
Why do you think your paper is highly
cited?
Streptococcus pneumoniae is a leading infectious cause of
morbidity and mortality worldwide. In 2000, the 7-valent pneumococcal
conjugate vaccine PCV7 (Prevnar™, Wyeth-Ayerst, Canada), a conjugated
pneumococcal polysaccharide which targets the seven serotypes (strains) of
pneumococcus that cause more than 80% of serious pneumococcal disease in
North American children, was introduced into the infant immunization
schedule in the US, and during the next few years we observed profound
reductions in the frequency of invasive pneumococcal disease (e.g.,
bacteremia and meningitis).
"This research can be used to inform
vaccine policy decisions in the U.S. and
other developed countries, but also in
developing countries where the disease burden
is much higher."
This occurred not only among vaccinated children, but also among young
children and adults who hadn't received the vaccine. PCV7 protects against
disease due to the seven serotypes that are covered by the vaccine.
However, there are approximately 90 different serotypes, so it is important
to describe changes in the frequency of disease due to the serotypes that
aren't covered by the vaccine.
Does it describe a new discovery, methodology, or
synthesis of knowledge?
This research confirmed that there has been a small increase in
pneumococcal disease due to serotypes that are not included in PCV7.
Would you summarize the significance of your paper
in layman's terms?
The bacterium, S. pneumoniae, is a leading cause of death
worldwide; it's a common cause of pneumonia, meningitis, and bloodstream
infections. PCV7, a vaccine for children that targets S.
pneumoniae, has resulted in a dramatic reduction in disease. There has
been a modest increase in disease due to types not covered by the vaccine.
These small increases should not overshadow the fact that PCV7 has
prevented serious illness and deaths in places where it is in use.
How did you become involved in this research, and
were there any problems along the way?
I became involved with this research when I joined the Epidemic
Intelligence Service with the Centers for Disease Control and Prevention
(CDC) in 2003. The Respiratory Diseases Branch at CDC tracks disease caused
by S. pneumoniae with the Active Bacterial Core surveillance
(ABCs) system. We analyzed data from ABCs to evaluate changes in the
serotypes causing invasive pneumococcal disease (e.g., meningitis and
bacteremia).
Where do you see your research leading in the
future?
The Respiratory Diseases Branch at CDC will continue to conduct
surveillance in order to identify changes in pneumococcal disease rates. We
anticipate that there may be further reductions in disease with the
introduction of newer vaccines that target more pneumococcal serotypes. We
are facing a crisis in clinical practice and public health due to an
increase in antibiotic resistant infections. I am currently conducting
research to determine how antibiotic use influences S. pneumoniae
resistance to antibiotics.
Do you foresee any social or political implications
for your research?
This research can be used to inform vaccine policy decisions in the US and
other developed countries, but also in developing countries where the
disease burden is much greater.
Lauri A. Hicks, D.O.
Medical Epidemiologist
Respiratory Diseases Branch
Centers for Disease Control and Prevention
Atlanta, GA, USA