656. Invasive Pneumococcal Disease in Alaska:  Impact of the 13-valent Pneumococcal Conjugate Vaccine
Session: Poster Abstract Session: Pneumococcal Vaccines
Friday, October 21, 2011
Room: Poster Hall B1
Background: 

Alaska Native children experienced some of the highest rates of invasive pneumococcal disease (IPD) in the world. After statewide introduction of the 7-valent pneumococcal conjugate vaccine (PCV7) in 2001, rates of IPD declined; however, non-PCV7 vaccine type IPD started increasing in 2004.  In 2010, the 13-valent pneumococcal conjugate vaccine (PCV13) was introduced statewide in Alaska.  We evaluated the impact of PCV13 on IPD one year after introduction.

Methods: 

Pneumococci isolated from sterile sites, reported through Alaska-wide laboratory based surveillance, were serotyped using standard methods.     Vaccine coverage was evaluated from electronic medical records at Alaska Native (AN) medical facilities and the National Immunization Survey. We defined a pre-vaccine time period April 2006-March 2009 and post-vaccine time period April 2010-March 2011. April 2009–March 2010 was excluded because PCV13 was introduced prelicensure in one high-risk region in 2009.

Results: 

PCV13 vaccine serotypes comprised 48% of IPD in the pre-vaccine time period. 

IPD in Alaska – Pre-PCV13 Introduction Versus Post-Introduction

Age,

Ethnic group

Serotype

Pre-introduction

April 2006-March 2009

Post-introduction

April 2010-March 2011

 

 

 

# Cases

Rate/100,000

# Cases

Rate/100,000

p-value

<5

All

98

59.4

11

19

<0.001

 

PCV13

63

38.2

4

6.9

<0.001

 

Non-PCV13

30

18.2

5

8.6

0.1

<5, AN

All

67

141

8

48.3

0.003

 

PCV13

40

84.2

4

24.1

0.01

 

Non-PCV13

22

46.3

2

12.1

0.05

<5, Non-AN

All

31

26.4

3

7.3

0.02

 

PCV13

23

19.6

0

0

0.004

 

Non-PCV13

8

6.8

3

7.3

0.9

≥5, AN

PCV13

43

12

12

9.8

0.5

 

Non-PCV13

105

29.4

27

22.2

0.2

≥5, Non-AN

PCV13

88

5.8

33

6.4

0.6

 

Non-PCV13

78

5.2

33

6.4

0.3

Conclusion: 

Within one year of introduction of PCV13 vaccine, PCV13-serotype IPD decreased 100% in non-AN and 71% in AN children <5 years of age. A decrease was noted in non-PCV13 disease among AN children, similar to patterns seen after introduction of PCV7.  A herd effect among older persons was not observed.  The potential development of herd immunity or replacement disease will be evaluated through continued surveillance.


Subject Category: I. Adult and Pediatric Vaccines

Michael Bruce, MD, MPH1, Jay Wenger, MD1, Tammy Zulz, MPH1, Rosalyn Singleton, MD2, Lisa Bulkow, MS3, Karen Rudolph, PhD1, Debby Hurlburt, RN BSN1 and Thomas Hennessy, MD MPH1, (1)Arctic Investigations Program, Centers for Disease Control and Prevention, Anchorage, AK, (2)Arctic Investigations Program - CDC, Anchorage, AK, (3)Arctic Investigations Program, CDC, Anchorage, AK

Disclosures:

M. Bruce, None

J. Wenger, Pfizer, Inc: Investigator, Research support

T. Zulz, None

R. Singleton, Pfizer, Inc: Investigator, Research support

L. Bulkow, None

K. Rudolph, None

D. Hurlburt, None

T. Hennessy, None

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