433-460 No. 35 Weekly epidemiological record …

1 Weekly epidemiological recordRelev pid miologique hebdomadaire 28 AUGUST 2015, 90th YEAR / 28 AO T 2015, 90e ANN ENo. 35, 2015, 90, 433 460 , 90, 433-460No. 35 Annual subscription / Abonnement annuelSw. fr. / Fr. s. 346. 0049-8114 Printed in SwitzerlandWORLD HEALTH ORGANIZATIONG enevaORGANISATION MONDIALE DE LA SANT Gen veContents433 Pertussis vaccines: WHO position paper August 2015 Sommaire433 Note de synth se: Position de l OMS concernant les vaccins anticoquelucheux ao t 2015433 Pertussis vaccines: WHO position paper August 2015 Introduction In accordance with its mandate to provide guidance to Member States on health policy matters, WHO issues a series of regularly updated position papers on vaccines and combinations of vaccines against diseases that have an international public health impact. These papers are concerned primarily with the use of vaccines in large-scale immunization programmes; they summarize essential background information on diseases and vaccines, and conclude with the current WHO position on the use of vaccines in the global context.

2 The papers are reviewed by external experts and WHO staff, and reviewed and endorsed by the WHO Strategic Advisory Group of Experts on immunization (SAGE) ( ). The GRADE methodology is used to systematically assess the quality of avail-able evidence. A description of the process followed for the development of vaccine position papers is available at: position papers are intended for use mainly by national public health officials and managers of immunization programmes. They may also be of interest to international funding agencies, vaccine advisory groups, vaccine manufacturers, the medical community, scientific media and the public. This document incorpo-rates the most recent developments in the field of pertussis disease and its preven-tion by vaccination; it replaces the posi-tion paper published in October 20101 and Note de synth se: Position de l OMS concernant les vaccins anticoquelucheux ao t 2015 Introduction Conform ment son mandat, qui est de conseiller les tats Membres sur les questions de politique sanitaire, l OMS publie une s rie de notes de synth se r guli rement actualis es sur les vaccins et les associations vaccinales contre les maladies ayant des r percussions sur la sant publique l chelon international.

3 Ces notes portent principalement sur l utilisa-tion des vaccins dans le cadre de programmes de vaccination grande chelle; elles r su-ment les informations g n rales essentielles sur les maladies et les vaccins et pr sentent en conclusion la position actuelle de l OMS concernant l utilisation de ces derniers dans le contexte notes de synth se sont examin es par un certain nombre d experts appartenant ou non au personnel de l OMS, puis elles sont soumises l examen et l approbation du Groupe stra-t gique consultatif d experts sur les vaccins et la vaccination (SAGE) ( ). Il est fait appel la m thodologie GRADE pour valuer de mani re syst matique la qualit des l ments dispo-nibles. On trouvera une description du proces-sus suivi pour laborer les notes de synth se sur les vaccins l adresse: notes s adressent avant tout aux autorit s de la sant publique et aux administrateurs des programmes de vaccination nationaux, mais elles peuvent aussi int resser des orga-nismes internationaux de financement, les fabricants de vaccins, le corps m dical, la presse scientifique et le grand public.

4 Le pr sent document int gre les avanc es les plus r centes concernant la coqueluche en tant que maladie et sa pr vention par vacci-nation. Il remplace la note de synth se publi e en octobre 20101 et les Recommanda-1 See No. 40, 2010, pp. 385 Voir No 40, 2010, pp. Weekly epidemiological record , NO. 35, 28 AUGUST 2015includes the revised guidance on the choice of pertussis vaccines published in July Recommendations on the use of pertussis vaccines were discussed by SAGE in April 20143 and in April 2015;4 the evidence presented at these meetings can be accessed at: and at respectively. The main revisions in this position paper concern the guidance on the choice of pertussis vaccine whole cell pertussis (wP) or acellular pertussis (aP) vaccine reflecting the updated guidance published in 2014, and incorporating recent evidence on the use of additional strategies, particularly vaccination during pregnancy, for prevention of early infant distribution and burdenPertussis (whooping cough) is an important cause of morbidity and mortality in infants worldwide, and continues to be a public health concern despite high vaccination coverage.

5 The disease, caused by the bacte-rium Bordetella pertussis, is endemic in all countries. Epidemic cycles have been occurring every 2 to 5 years (typically 3 to 4 years), even after the introduction of effective vaccination programmes and the achievement of high vaccination vaccines became widely available in the 1950s, pertussis was one of the most common childhood diseases worldwide. Limited early data indicated that most individuals were infected in childhood, of whom >50% developed clinical disease. According to pre-vaccine data from the United States of America (USA), approximately 80% of cases occurred in children <5 years of age and less than 3% of cases in persons aged 15 years. Similar patterns were reported in pre-vaccine studies from developing countries, including in Africa and southern Asia.

6 Case fatality rates (CFR) were and remain highest in Historic early data were likely biased towards the more severe presentation of pertussis disease and may not reflect the full burden of milder disease across all age introduction of effective infant vaccination programmes was associated with a steep decline in the number of pertussis cases and deaths in children. Pertussis vaccine (combined with diphtheria and teta-nus toxoids) has been used in the Expanded Programme tions r vis es concernant le choix des vaccins anticoquelucheux: juillet Les recommandations relatives l utilisation des vaccins anticoquelucheux ont t discut es par le SAGE en avril 20143 et en avril 2015;4 les l ments pr sent s lors de ces r unions peuvent tre consult s l adresse: et l adresse: respectivement. Les principales modifications introduites dans cette note de synth se portent sur les recommandations concernant le choix des vaccins anticoquelucheux germes entiers ou acellulaires et refl tent la mise jour diffus e en 2014 ainsi que l incor-poration de donn es r centes sur le recours des strat gies compl mentaires, notamment la vaccination pendant la gros-sesse, pour pr venir la mortalit infantile pr coce.

7 Consid rations g n rales pid miologie Distribution de la maladie et charge de morbidit La coqueluche est une cause importante de morbidit et de mortalit infantile dans le monde et demeure un probl me de sant publique malgr des niveaux lev s de couverture vacci-nale. La maladie, caus e par la bact rie Bordetella pertussis, est end mique dans tous les pays. Des cycles pid miques, sont enregistr s tous les 2 5 ans (typiquement tous les 3 4 ans), m me depuis l introduction de programmes de vaccination effi-caces et l obtention d une forte couverture que les vaccins ne deviennent largement disponibles dans les ann es 1950, la coqueluche faisait partie des maladies de l enfant les plus courantes partout dans le monde. Des donn es anciennes limit es indiquaient que la plupart des individus taient infect s pendant l enfance, avec apparition de la maladie clinique chez plus de la moiti d entre eux.

8 D apr s les donn es de l poque pr -vaccinale provenant des tats-Unis d Am rique (USA), 80% environ des cas apparaissaient chez des enfants de <5 ans et <3% de cas concernaient des individus de 15 ans. Des tendances similaires ont t rapport s par des tudes men es avant la vaccination dans des pays en d veloppement, et notamment en Afrique et dans le sud de l Asie. C est parmi les nourrissons, que les taux de l talit (TL) taient et demeurent les plus lev Les donn es historiques anciennes taient probablement biais es, donnant une image plus s v re de la coqueluche qu elle ne l avait t en r alit , et pourraient ne pas refl ter la charge de maladie plus b nigne dans l ensemble des tranches d introduction de programmes de vaccination infantile efficace a t associ e une diminution brutale du nombre de cas de coqueluche et de d c s chez les enfants.

9 Le vaccin anticoquelu-cheux (associ aux anatoxines dipht rique et t tanique) a t utilis dans le cadre du Programme largi de vaccination (PEV) 2 See No. 30 , 2014, pp. 337 See , 2014, pp. 221 See No. 22 , 2015, pp. 261 280. 5 Edwards KM, Decker MD. Pertussis vaccines. In: Plotkin S, Orenstein W, Offit P, eds. Vaccines, 6th ed. Philadelphia, Saunders, 2013:447 Report from the SAGE Working Group on Pertussis vaccines, 26 27 August 2014 meeting, Geneva, Switzerland. Available at ; accessed July Voir No 30 , 2014, pp. Voir No 21, 2014, pp. Voir No 22, 2015, pp. 261-280. 5 Edwards KM, Decker MD. Pertussis vaccines. In: Plotkin S, Orenstein W, Offit P, eds. Vaccines, 6th ed. Philadelphia, Saunders, 2013:447 Report from the SAGE Working Group on Pertussis vaccines, 26 27 August 2014 meeting, Ge-neva, Switzerland. Disponible sur ; consult en juillet EPIDEMIOLOGIQUE HEBDOMADAIRE, No 35, 28 AO T 2015 435on Immunization (EPI) since its inception in 1974.

10 It was estimated that that without vaccination there would have been > million pertussis related deaths globally in In 2013, according to WHO estimates, pertus-sis was still causing around 63 000 deaths in children aged <5 years,8 although there is considerable uncer-tainty over these estimates in view of the paucity of reliable surveillance data, particularly from developing countries. In 2014 global vaccination coverage with 3 doses of a pertussis-containing vaccine was esti-mated at 86%.9A shift in the age distribution of pertussis towards older age groups (adolescents and young adults) has been reported in recent years in some high income countries, in particular where aP vaccines have replaced wP vaccines for primary vaccination series. The age shifts may be explained in part by an increasing recognition of the less typical disease manifestations in older subjects, more sensitive laboratory testing, and more sensitive surveillance extended to cover the entire life span.