Using age-stratified incidence data to examine the transmission consequences of pertussis vaccination.
Pertussis is a highly infectious respiratory disease that has been on the rise in many countries worldwide over the past several years. The drivers of this increase in pertussis incidence remain hotly debated, with a central and long-standing hypothesis that questions the ability of vaccines to eliminate pertussis transmission rather than simply modulate the severity of disease. In this paper, we present age-structured case notification data from all provinces of Thailand between 1981 and 2014, a period during which vaccine uptake rose substantially, permitting an evaluation of the transmission impacts of vaccination. Our analyses demonstrate decreases in incidence across all ages with increased vaccine uptake - an observation that is at odds with pertussis case notification data in a number of other countries. To explore whether these observations are consistent with a rise in herd immunity and a reduction in bacterial transmission, we analyze an age-structured model that incorporates contrasting hypotheses concerning the immunological and transmission consequences of vaccines. Our results lead us to conclude that the most parsimonious explanation for the combined reduction in incidence and the shift to older age groups in the Thailand data is vaccine-induced herd immunity.
Department of Mathematics and Statistics, Williams College, Williamstown, MA 01267, USA. Electronic address: jcb5@williams.edu.
J C
JC
Blackwood
Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA.
D A T
DA
Cummings
Bureau of Epidemiology, Ministry of Public Health, Nonthaburi, Thailand.
S
S
Iamsirithaworn
Odum School of Ecology, University of Georgia, Athens, GA 30606, USA; Department of Infectious Diseases, School of Veterinary Medicine, University of Georgia, Athens, GA 30606, USA; Fogarty International Center, National Institutes of Health, Bethesda, MD 20892, USA.
P
P
Rohani
D006801:Humans; D032521:Immunity, Herd; D015994:Incidence; D010567:Pertussis Vaccine; D014611:Vaccination; D014917:Whooping Cough / Q000453:epidemiology*
D010567:Pertussis Vaccine
Disease transmission; Epidemiology; Immunity; Mathematical model; Pertussis
Epidemics. 2011 Sep;3(3-4):183-8
22094341
J Pediatr. 1985 Aug;107(2):180-3
3874941
Lancet Infect Dis. 2006 Feb;6(2):112-7
16439331
Proc Natl Acad Sci U S A. 2011 Apr 26;108(17):7259-64
21422281
Am J Epidemiol. 2015 Jun 15;181(12):921-31
26022662
Lancet. 2000 Apr 29;355(9214):1553-4
10801196
Br Med J (Clin Res Ed). 1988 Jun 4;296(6636):1570-2
3135011
PLoS Comput Biol. 2015 Apr 23;11(4):e1004138
25906150
Epidemiol Infect. 2014 Apr;142(4):672-84
23324361
Proc Natl Acad Sci U S A. 2014 Jan 14;111(2):575-6
24381159
PLoS Med. 2010 Jun 22;7(6):e1000291
20585374
mBio. 2014 Jun 10;5(3):e01339-14
24917600
Science. 2010 Nov 12;330(6006):982-5
21071671
PLoS One. 2016 Feb 02;11(2):e0148338
26837004
Proc Natl Acad Sci U S A. 2014 Jan 14;111(2):787-92
24277828
J Infect Dis. 2014 Jun 15;209(12):1981-8
24443545
Epidemiol Infect. 1988 Jun;100(3):419-42
3378585
Proc Biol Sci. 2016 Jan 13;283(1822):
26763701
J Infect Dis. 2014 Apr 1;209(7):978-81
24626532
Br Med J. 1972 Aug 19;3(5824):448-51
4341645
J Infect Dis. 2002 May 15;185(10):1448-53
11992280
Lancet. 1982 Mar 20;1(8273):666-9
6121976
SIAM J Appl Math. 2014;74(6):1810-1830
25878365
Clin Infect Dis. 1999 Jun;28(6):1230-7
10451158
Proc Natl Acad Sci U S A. 2015 Feb 3;112(5):E472-7
25605878
Proc Natl Acad Sci U S A. 2014 Feb 18;111(7):E716-7
24516173
Br Med J. 1965 Jul 3;2(5452):11-3
14305343
Pediatr Infect Dis J. 1987 Feb;6(2):141-4
3562135
BMC Med. 2015 Jun 24;13:146
26103968
Lancet. 2006 Jun 10;367(9526):1926-36
16765762
Rev Infect Dis. 1989 May-Jun;11 Suppl 3:S514-7
2762697
Vaccine. 2013 Dec 2;31(49):5903-8
24139837
Proc Natl Acad Sci U S A. 2013 Jun 4;110(23):9595-600
23690587
Paediatr Respir Rev. 2008 Sep;9(3):201-11; quiz 211-2
18694712
PLoS Med. 2008 Mar 25;5(3):e74
18366252