Over 600 delegates from 64 countries attended the 5th International Symposium on Pneumococci and Pneumococcal Diseases
Over 600 delegates from 64 countries attended the 5th International Symposium on Pneumococci and Pneumococcal Diseases in central Australia. PneumoADIP was proud to be one of the sponsors to fund 57 fellowships that supported delegates from 26 developing countries. During this five-day conference, 120 presentations and 284 posters were showcased - over 30 presentations and posters representing PneumoADIP-sponsored research and surveillance networks.
Numerous abstracts were presented on serotype replacement disease including from Northern California Kaiser Permanente (NCKP), Alaska Natives, Navajo, and the U.S. Active Bacterial Core surveillance. Comparing the experience among these populations, it is apparent that there is considerable variability in the presence and degree of replacement disease that is occurring. There is not a uniform experience. The drivers of this variability are not known but might relate to strategies of vaccine introduction, population characteristics, prevalence of non-vaccine type (NVT) disease prior to introduction or other characteristics. In NCKP, there has been no replacement disease observed but the pre-introduction NVT rates emphasize that there is considerable year-to-year variability occurring, so pre-post introduction rate analyses must consider the expected variability in serotype specific disease rates over time. In Alaska, there has been a significant increase in the rate of 19A disease among young children. Among Navajo, there is no change in the overall NVT rates, however some NVT serotypes have increased and others decreased since use of Prevnar began 9 years ago. In the U.S. there is replacement disease which has stabilized in terms of the absolute values.
The use of PS23 following priming with PCV was presented by several abstracts. The two notable findings were the immunogenicity of non-PCV serotypes (except 12F) when PS23 was administered at 12 months of age to Fijian infants. The second notable finding was the reduction of VT carriage following PCV among Tiwi Island children which was not sustained following a booster dose with PS23. The impact of PS23 on the immune system, carriage and disease is yet to be fully understood.
The immune system correlates of protection against carriage were explored in a number of presentations. Vaccine induced protection from carriage is certainly related to induction of serum serotype specific IgG. Naturally induced protection against carriage is not likely to be only serotype specific IgG but is likely to also involve CD4 cells, cytokines and other locally induced immune responses.
Alternate dosing schedules with neonatal dosing, 2 dose schedules, 3 dose schedules and boosting with PS23 are all under evaluation and likely to yield interesting results on optimal dosing schedules. Maternal antibody interference with early dosing seems to occur but the impact on disease prevention is not clear.
Former industry executives Michel Greco and Kevin Reilly co-chaired this 90-minute symposium sponsored by PneumoADIP. Panel speakers included Kate O'Brien, Angeline Nanni, and Orin Levine. First O'Brien presented on "The case for accelerated pneumococcal vaccination in developing countries." Nanni then presented on "PneumoADIP's Approach to Building a Win-Win-Win Situation for Industry, Donors & Countries." Levine spoke on behalf of Ruth Levine (no relation) from Center for Global Development on "Immunization & Vaccine Financing: Implications for the Research Community." After presentations, 30 minutes were dedicated to questions and discussions whereby the scientific community posed questions about financing and supply concerns and co-chairs Greco and Reilly explained past precedent and future directions for industry's role in supplying vaccines. Issues of discussion included: incentives for industry to increase capacity for the low income-high volume market, the roles for multi-national and emerging vaccine manufactures in supplying the low-income market, country's capacity and willingness to co-pay for the vaccines.
PneumoADIP conducted a quick survey in order to understand the current opinions and perceptions of the technical community about feasibility of pneumococcal vaccine introduction in developing countries. There appears to be consensus in key issues reflecting the current evidence from pneumococcal vaccine trial results and routine pneumococcal immunization program findings.
*Summer 2005 Survey: Answer to same question, 71% (n=90) responded “yes.”
ISPPD4 Survey: Answer to same question, 63% (n=130) responded “yes.”
A presentation given by PneumoADIP's Director of Vaccine Finance and Supply, Angeline Nanni at ISPPD5.
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A presentation prepared by Center for Global Development's Ruth Levine.
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