Printable Copy |
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)
|------------------|
| |
|REVIEW ARTICLE |
|------------------|
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.