Economic evaluation of pneumococcal conjugate vaccination in The Gambia.
BACKGROUND
Gambia is the second GAVI support-eligible country to introduce the 7-valent pneumococcal conjugate vaccine (PCV7), but a country-specific cost-effectiveness analysis of the vaccine is not available. Our objective was to assess the potential impact of PCVs of different valences in The Gambia.


METHODS
We synthesized the best available epidemiological and cost data using a state-transition model to simulate the natural histories of various pneumococcal diseases. For the base-case, we estimated incremental cost (in 2005 US dollars) per disability-adjusted life year (DALY) averted under routine vaccination using PCV9 compared to no vaccination. We extended the base-case results for PCV9 to estimate the cost-effectiveness of PCV7, PCV10, and PCV13, each compared to no vaccination. To explore parameter uncertainty, we performed both deterministic and probabilistic sensitivity analyses. We also explored the impact of vaccine efficacy waning, herd immunity, and serotype replacement, as a part of the uncertainty analyses, by assuming alternative scenarios and extrapolating empirical results from different settings.


RESULTS
Assuming 90% coverage, a program using a 9-valent PCV (PCV9) would prevent approximately 630 hospitalizations, 40 deaths, and 1000 DALYs, over the first 5 years of life of a birth cohort. Under base-case assumptions ($3.5 per vaccine), compared to no intervention, a PCV9 vaccination program would cost $670 per DALY averted in The Gambia. The corresponding values for PCV7, PCV10, and PCV13 were $910, $670, and $570 per DALY averted, respectively. Sensitivity analyses that explored the implications of the uncertain key parameters showed that model outcomes were most sensitive to vaccine price per dose, discount rate, case-fatality rate of primary endpoint pneumonia, and vaccine efficacy against primary endpoint pneumonia.


CONCLUSIONS
Based on the information available now, infant PCV vaccination would be expected to reduce pneumococcal diseases caused by S. pneumoniae in The Gambia. Assuming a cost-effectiveness threshold of three times GDP per capita, all PCVs examined would be cost-effective at the tentative Advance Market Commitment (AMC) price of $3.5 per dose. Because the cost-effectiveness of a PCV program could be affected by potential serotype replacement or herd immunity effects that may not be known until after a large scale introduction, type-specific surveillance and iterative evaluation will be critical.
Kim
Sun-Young
SY
Department of Health Policy and Management, Harvard School of Public Health, Center for Health Decision Science, Boston, MA, USA. sykim@hsph.harvard.edu
Lee
Gene
G
Goldie
Sue J
SJ
D002675:Child, Preschool; D003362:Cost-Benefit Analysis; D005714:Gambia / Q000453:epidemiology; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D011008:Pneumococcal Infections / Q000191:economics* / Q000453:epidemiology / Q000517:prevention & control*; D022242:Pneumococcal Vaccines / Q000008:administration & dosage* / Q000191:economics* / Q000276:immunology; D014611:Vaccination / Q000191:economics*; D018074:Vaccines, Conjugate / Q000008:administration & dosage / Q000191:economics / Q000276:immunology
D022242:Pneumococcal Vaccines; D018074:Vaccines, Conjugate
Lancet. 2007 Feb 3;369(9559):389-96
17276779
Lancet. 2006 Oct 28;368(9546):1495-502
17071283
Educ Health (Abingdon). 2003 Jul;16(2):230
14741909
JAMA. 2007 Apr 25;297(16):1825-6
17456826
Lancet. 2007 Jul 21;370(9583):218-219
17658389
J Infect Chemother. 2008 Jun;14(3):180-7
18574652
Rev Panam Salud Publica. 2009 Mar;25(3):270-9
19454155
Bull World Health Organ. 2007 Nov;85(11):833-42
18038073
Lancet. 2005 Mar 26-Apr 1;365(9465):1139-46
15794968
N Engl J Med. 2003 Oct 2;349(14):1341-8
14523142
N Engl J Med. 2003 May 1;348(18):1737-46
12724479
MMWR Morb Mortal Wkly Rep. 2008 Oct 24;57(42):1148-51
18946462
BMC Infect Dis. 2008 Jun 11;8:81
18547404
Vaccine. 1995;13(8):707-14
7483785
Eur J Health Econ. 2009 Feb;10(1):25-38
18379830
BMC Med. 2009 Sep 14;7:47
19751516
Pediatr Infect Dis J. 1992 Jun;11(6):466-73
1608684
Cost Eff Resour Alloc. 2009 Jan 22;7:3
19161598
Expert Rev Vaccines. 2009 Nov;8(11):1479-500
19863240
Trop Med Int Health. 2006 Jul;11(7):1128-35
16827713
Health Econ. 2000 Jan;9(1):19-35
10694757
Vaccine. 2007 Mar 22;25(13):2398-405
17028081
Pediatr Infect Dis J. 2002 Nov;21(11):1004-7
12442020
Trop Med Int Health. 2000 Aug;5(8):528-33
10995093
Vaccine. 2007 Mar 22;25(13):2451-7
17023095
Wkly Epidemiol Rec. 2008 Oct 24;83(43):388-92
18949860
Lancet. 2005 Mar 26-Apr 1;365(9465):1113-4
15794951
Pediatr Infect Dis J. 1994 Feb;13(2):122-8
8190537
Pediatr Infect Dis J. 1991 Jan;10(1):33-41
1848364
Vaccine. 2009 Aug 21;27 Suppl 3:C3-5
19552985
J Trop Pediatr. 1999 Feb;45(1):51-3
10191594
Vaccine. 2008 Jul 4;26(29-30):3719-26
18514974
Trop Med Int Health. 2000 Mar;5(3):207-13
10747284
Vaccine. 2006 May 29;24(22):4727-36
16616973
Bull World Health Organ. 2005 May;83(5):353-9
15976876
Pediatr Infect Dis J. 1996 May;15(5):431-7
8724066
Pediatr Infect Dis J. 1998 Jan;17(1):23-8
9469390
Vaccine. 2004 Oct 22;22(31-32):4203-14
15474710
Trop Med Int Health. 2007 Nov;12(11):1377-85
18045264
Bull World Health Organ. 2007 Jul;85(7):511-8
17768499
Health Econ. 2002 Jan;11(1):23-31
11788979
Pediatr Infect Dis J. 2006 Aug;25(8):700-5
16874169
Pediatr Infect Dis J. 1991 Jan;10(1):42-7
2003054
Lancet. 2005 Jul 9-15;366(9480):144-50
16005337
Health Econ. 2001 Oct;10(7):675-80
11747050
MMWR Morb Mortal Wkly Rep. 2005 Sep 16;54(36):893-7
16163262
BMJ. 2010 Jun 02;340:c2509
20519267
Lancet. 2007 Jul 21;370(9583):285-289
17658399
Eur J Pediatr. 2010 Sep;169(9):1123-8
20383524