Fifteen Years of Pneumococcal Carriage Studies among Navajo and White Mountain Apache Communities
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Transcript of Fifteen Years of Pneumococcal Carriage Studies among Navajo and White Mountain Apache Communities
•A double-blinded, controlled study of the efficacy, immunogenicity, safety and tolerability, and effectiveness of a pneumococcal conjugate vaccine containing seven serotypes (6B, 14, 19F, 23F, 18C, 4 and 9V) compared to a control meningococcal c vaccine in Navajo and Apache Indian infants. (NNR.97.18)• Long term impact of the pneumococcal conjugate vaccine on pneumococcal nasopharyngeal colonization and immune correlates for disease protection. (NNR.05.165)• Impact of 13-valent pneumococcal conjugate vaccine (PCV-13) on pneumococcal disease and colonization among Native American communities. (NNR.09.253)
Fifteen Years of Pneumococcal Carriage Studies among Navajo and White Mountain Apache
Communities
Background
What are pneumococcal carriage studies?
• Pneumococcus lives in the back of the nose and throat (nasopharynx or NP) this is called carriage
• Carriage always comes before disease
Why do we study “carriage” of pneumococcus?
• Identify the types of pneumococcus present in the population
• Describe patterns of disease transmission• Identify antibiotic resistant pneumococcus
strainsThis information can tell us…
…the types of pneumococcus are most likely to cause disease.
Carriage Studies
How do we sample pneumococcus from the nasopharynx?
• A swab is inserted through the nose into the back of the nose/throat (nasopharynx or NP)
• This procedure does not hurt, but can tickle and make the eyes water.
• It is done quickly and in a continuous motion to minimize discomfort and avoid injury.
What carriage studies have been done?
Original NP Family NP Long-term NP PCV13 Impact
Years conducted 1997-2000 2001-2002 2006-2008 2010-present
Number participants 844 5507 1072 4989
Number households 511 1112 300 1333
NP swab collection
One per person
One per person
Seven per person
One per person
Number NP swabs collected
5157 5215 6545 4989
Conduct of Carriage Studies
Who supports and approves our studies?
• Local community members• Indian Health Service• Navajo Nation IRB
Where do we enroll participants?
Visit families at their home
We may also enroll participants in the clinic
How do we enroll participants?
Participants consent to enroll into the study
What happens to the NP swabs?
They are processed in the laboratory
How is pneumococcus isolated?1. Pneumococcus from NP swab is grown on a blood-agar plate
Colony of pneumococcus
2. Then, tests are run to determine the type of pneumococcus
Results of Carriage Studies
0 - <2 yr 2 - 7 yr 8 - 17 yr 18 - 49 yr 50+ yr0%
20%
40%
60%
80%
100%
55% 53%
32%
11% 11%Perc
ent p
neum
ococ
cus p
ositi
veWhat can carriage studies tell us?
Take Home Message #1: Carriage is most common among young children
*Data from the Long-term NP study
0-11 months 12-23 months 2-<5 years 5-<8 years0%
10%
20%
30%
40%
50%
43%
36%33% 33%
3% 3% 2% 2%
Pre-PCV7 Introduction (1998-2000)Post-PCV7 Introduction (2006-2008)
Perc
ent v
acci
ne-ty
pe c
arria
ge
*Data from the Original NP study and Long-term NP study
Take Home Message #2: PCV7 reduces carriage of vaccine-type pneumococcus
*Data from the Family NP study
<5 years >=18 years0.0%
5.0%
10.0%
15.0%
20.0%
25.0%
19.0%
4.1%
12.0%
2.4%
families without a vaccinated childfamilies with a vaccinated child
Perc
ent v
acci
ne-ty
pe ca
rria
geTake Home Message #3: Vaccinating
children can reduce vaccine-type carriage in unvaccinated family members
What can multiple carriage studies over time tell us?
Percent of individuals with any type of pneumococcal carriage is unchanged over time
<2 yr 2 - 7 yr 8 - 17 yr 18 - 49 yr 50+ yr0%
20%
40%
60%
80%
100%
55% 53%
32%
11% 11%
55% 55%
32%
13% 16%
2006-2008 (LTNP study)2010-present (PCV13 study)
Perc
ent p
neum
ococ
cus p
ositi
ve
Future carriage study on Navajo Nation
• New type of vaccine on the horizon• Targets all types of pneumococcus (not only 7
types or 13 types)• May help to further reduce pneumococcal
disease and carriage
Acknowledgements
• Participants from the Navajo and White Mountain Apache tribes
• Community members who supported these studies
• Nurses and research program assistants • IRBs of the Navajo Nation, Phoenix Area IHS,
and Johns Hopkins School of Public Health• Indian Health Service providers, staff and
facilities
Thank you!