CSU 49/2009: READER COMMENT/ EFFICACY OF PNEUMOCOCCAL VACCINATION IN CHILDREN YOUNGER THAN 24 MONTHS

Wednesday, 2nd of September 2009 Print

CSU 49/2009: READER COMMENT/ EFFICACY OF PNEUMOCOCCAL VACCINATION
 IN CHILDREN YOUNGER THAN 24 MONTHS
 
 READER COMMENT
 
 
 From reader Alan Brooks, PATH
 
 I am pleased to share with you the news that the Phase 3 trial of the RTS,S
 malaria vaccine candidate has begun in Bagamoyo, Tanzania, on May 26. This
 is the first of a several centers across Africa to initiate the Phase 3
 study, which will also include centers in Kenya, Malawi, Mozambique, Gabon,
 Ghana and Burkina Faso.
 
  The trial represents an important milestone – for both MVI and GSK, as
 well as for the African research centers and their Northern partners. We
 also would like to acknowledge the trial participants and their families
 without whom this study would not be possible.
  RTS,S is the first malaria vaccine candidate to demonstrate significant
 efficacy with a clinically acceptable safety following 10 years of clinical
 research in Africa. Recent Phase II studies showed that the candidate
 vaccine reduced the risk of episodes of clinical malaria in children 5-17
 months of age by 53 percent and can be administered together with standard
 infant vaccines in national immunization programs on the continent.
 
  Developing a vaccine against malaria, a scientific challenge for decades,
 is critical to defeating the disease. A vaccine will complement existing
 interventions, such as bed nets and effective drug therapies. Malaria kills
 approximately 900,000 people a year worldwide and sickens tens of millions
 more, most of them children living in Sub-Saharan Africa. A safe and
 effective vaccine is an important component of a comprehensive malaria
 control program.
 
  While the start of Phase 3 is a key step forward, many challenges remain.
 We must continue to work in collaboration with many partners to ensure this
 vaccine, if proven effective, reaches those who need it most. We’re
 grateful to the many organizations that have worked with us or supported us
 during this process and that will play a crucial role in the years to come.
 
  In addition to our partners at GSK and African study centers, we
 acknowledge with appreciation the support for the clinical trials from the
 Malaria Clinical Trials Alliance and the tremendous generosity and vision
 of the Bill & Melinda Gates Foundation that have helped bring us to where
 we are today.
 
  Kind regards,
  Alan
  Alan Brooks
 Director, Policy and Access
 The PATH Malaria Vaccine Initiative
 Bâtiment Avant Centre; 13 chemin du Levant
 01210 Ferney-Voltaire  France
 
 EFFICACY OF PNEUMOCOCCAL VACCINATION IN CHILDREN YOUNGER THAN 24 MONTHS
 
 The last Cochrane review of pneumoccal vaccination efficacy
 against invasive pneumococcal disease (IPD) dates from 2004. In this
 meta-analysis from Pediatrics, Pavia and colleagues review the published
 articles on pneumococcal vaccination from 2000 to 2008 and conclude that it
 is associated with 89 percent efficacy against vaccine serotypes, or 63 to
 74 percent against all serotypes.
 
 The gap between vaccine serotypes and all serotypes will narrow as the
 widely available
 7-valent vaccine of today,  studied in most of the publications analyzed
 here, is succeeded, for example, by 10- and 13-valent vaccines. Because the
 distribution of serotypes varies  between countries, so, too, will the
 impact of pneumococcal vaccines.
 
 Summary is below; full text is at
 http://pediatrics.aappublications.org/cgi/content/abstract/123/6/e1103?etoc
 
 Good reading.
 Bob Davis
 
 
 
 Published online May 26, 2009
 PEDIATRICS Vol. 123 No. 6 June 2009, pp. e1103-e1110
 (doi:10.1542/peds.2008-3422)
 
 
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 |REVIEW ARTICLE |
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 Efficacy of Pneumococcal Vaccination in Children Younger Than 24 Months: A
 Meta-Analysis
 
 Maria Pavia, MD, MPHa, Aida Bianco, MDa, Carmelo G. A. Nobile, MDa, Paolo
 Marinelli, MDb and Italo F. Angelillo, DDS, MPHb
 a Department of Hygiene, Medical School, University of Catanzaro "Magna
 Græcia," Catanzaro, Italy
 b Department of Public, Clinical, and Preventive Medicine, Second
 University of Naples, Naples, Italy
 
 CONTEXT. Pneumococcal conjugate bacterial vaccines that are able to prevent
 invasive disease and mucosal infections have been developed.
 
 OBJECTIVE. A meta-analysis of published data from trials on pneumococcal
 conjugate vaccine was performed to determine the efficacy in reducing the
 incidence of invasive disease caused by Streptococcus pneumoniae,
 pneumonia, and acute otitis media in healthy infants younger than 24
 months.
 
 METHODS. A systematic search of the literature was conducted. Controlled
 clinical trials had to compare the protective efficacy of the pneumococcal
 conjugate vaccine in reducing the incidence of invasive disease caused by S
 pneumoniae, pneumonia, and acute otitis media in healthy infants with
 placebo or control vaccines. Information was extracted by using a
 standardized protocol.
 
 RESULTS. The efficacy of pneumococcal conjugate vaccine in the reduction of
 invasive pneumococcal disease was 89% involving vaccine serotypes in both
 the intention-to-treat and per-protocol analyses and ranged from 63% to 74%
 for all serotypes. The efficacy to prevent acute otitis media sustained by
 vaccine serotypes was 55% in the intention-to-treat and 57% in the
 per-protocol analyses, whereas it was 29% to prevent otitis involving all
 serotypes in the per-protocol analysis. Finally, in the intention-to-treat
 and per-protocol analyses, the efficacy to prevent clinical pneumonia was
 6% and 7%, respectively, whereas for the prevention of radiograph-confirmed
 pneumonia it was 29% and 32%, respectively.
 
 CONCLUSIONS. The pneumococcal conjugate vaccine produces a significant
 effect regarding prevention of invasive pneumococcal disease. Results on
 prevention of otitis or pneumonia have been less striking, but considering
 the high burden of these diseases in infants, even a low efficacy has
 potential for tremendous impact on the health of infants in developing and
 industrialized countries.
 
 Key Words: acute otitis media • efficacy • infants • invasive pneumococcal
 disease • pneumococcal conjugate vaccine • pneumonia
 Abbreviations: PCV—pneumococcal conjugate vaccine • PCV-n—n-valent
 pneumococcal conjugate vaccine • IPD—invasive pneumococcal disease •
 ITT—intention to treat • PP—per protocol • RR—relative risk • CI—confidence
 interval
 
 Accepted Feb 10, 2009.
 

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