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!