March 26th, 2006 marks the 1-year anniversary of The Gambia pneumococcal conjugate vaccine trial in The Lancet
March 26th marks the 1-year anniversary of the landmark publication of The Gambia pneumococcal conjugate vaccine trial in The Lancet. Dr. Felicity Cutts, the Principal Investigator, spoke with PneumoADIP.
One year after publication of The Gambia Trial results for the pneumococcal vaccine, how significant is this article?
It is very significant as it shows clear protection against pneumonia, invasive pneumococcal disease, hospital admissions, and overall mortality among young children in rural Africa.
Have the results of this trial changed the scientific community's view on pneumococcal vaccines?
Yes, I think so - there is a move towards promotion of pneumococcal conjugate vaccine introduction in Africa at least, although there is understandable caution in extrapolating from this trial to predicting the impact of 7-valent vaccine. The impact of the trial would have been much greater if the 9-valent vaccine that was evaluated in The Gambia and South Africa had been available for national immunization programs.
What if any, have been the major implications of this trial since the results were published in 2005?
It contributes to a growing body of evidence of the importance of pneumococcal infection as a major cause of child mortality. The recent series of papers on child survival have called for renewed investment in interventions to reach the MDGs (Millenium Development Goals), while at the same time, the difficulties in implementing IMCI (Integrated Management of Childhood Illness) and in demonstrating impact of IMCI have been described in several countries. Pneumococcal and Hib vaccines offer a complementary way to reduce pneumonia and invasive disease burden and are likely to be more amenable to achieving impact in hard-to-reach populations.
What impact has the trial had on the population and/or policymakers in the Gambia?
Following the trial, we conducted a mass vaccination campaign of all children aged 2-4 years in the study area (covering about one third of The Gambia) so all children in this age group had access to the benefits from pneumococcal vaccine (7-valent). During the campaign we also disseminated the results of the trial through personal contacts and radio announcements. We don't have data on how the population views the results, however.
Policymakers in the Gambia want to introduce conjugate vaccines and are willing to accept 7-valent vaccine although they would have much preferred 9-valent. They aim to establish surveillance to monitor the impact of widespread vaccination.
What is the next step in sustaining prevention of pneumococcal disease in children under 5 in The Gambia?
Obtaining funding for surveillance and introduction of 7-valent vaccine, until vaccines of broader coverage become available. Further implementation of the IMCI strategy for secondary prevention of complications of pneumococcal disease is also important. MRC is conducting a trial to compare two different antimicrobial regimens (short-course high dose amoxicillin versus standard course of co-trimoxazole) for treatment of pneumonia and the results of that trial should also assist in improving therapy for pneumonia.
In an end of year review of favorite papers in infectious disease, The Lancet (Vol 5, December 2005) ranks The Gambia pneumococcal vaccine trial paper 5 out of 35. How does the trial rank for you, in terms of your own publications?
Number one in terms of potential public health importance. I hope, however, that the non-availability of the 9-valent vaccine does not lengthen the time between research results and public health action too greatly.
What are the most interesting developments in preventing pneumococcal disease in the developing world today?
We are all anxiously awaiting the results of the Philippines trial. The evaluation of newer conjugate vaccines of broader coverage in Latin America and elsewhere is also critically important. New financing mechanisms need to be tested and it will be very important to find out if the assumptions underlying GAVI, IFFIM and AMC are valid. The common protein antigen approach to pneumococcal vaccines is also exciting.