The main results of the inactivated poliovirus vaccine (IPV) clinical trial have been published in Lancet Global Health. The trial was undertaken as part of a series of trials funded by Bill & Melinda Gates Foundation and has generated key data required as part of the polio eradication endgame.
Specifically, the trial looked at the safety of giving IPV alongside the measles and rubella and the yellow fever vaccines already included in the Expanded Programme on Immunisation (EPI) schedule at 9 months of age and aimed to identify interference between the three vaccines when given together. There were no safety concerns. No interference was identified which is considered likely to preclude the future co-administration of the vaccines if a booster dose of IPV is to be introduced into the EPI schedule at nine months.
Conducted at MRC Unit The Gambia, the trial recruited 1504, nine and ten-month-old infants over a period of 6 months at Sukuta health centre, Faji Kunda health centre and at Jammeh Foundation for Peace Hospital. The trial also investigated different ways to give the IPV vaccine. Fractional (one-fifth) doses given in tradermally (ID) were compared to full (0.5mL) intramuscular (IM) doses. Both ID and IM needle-free-jet-injection devices were also tested. Dose-sparing fractional doses of IPV are currently seen as extremely important within the endgame strategy given global IPV supply problems which are delaying IPV roll out and mean some countries which have already introduced the vaccine will be left short.The trial provides the only data from sub-Saharan Africa which looks at the safety and immunogenicity of ID fractional doses of IPV or of jet injector devices and thus is seen as critical to future implementation in this setting, as is expected to be required.
Dr Ed Clarke, the principal investigator of the trial commented “The whole trial team worked exceptionally hard to maintain over 97% follow-up and to ensure the quality and relevance of the final data generated. I sincerely thank the clinicians, field, data and laboratory teams and other support personnel at the MRCG, and also in the external laboratories with which we worked, for their commitment to this important trial. As a team, we also thank the staff at the health centres through which we recruited as well as The Gambia government EPI office and the Ministry of Health and Social Welfare for their continued support. Polio eradication is now a very real possibility, but addressing critical research questions, such as those addressed in this study, efficiently remains critical if this extraordinary goal is to be achieved.”
Professor Kampmann, senior trial co-investigator and Head of the Vaccines & Immunity theme commented: “I am delighted that our work can inform a global health policy for an infectious disease we are hoping to eradicate in the very near future, and to see these results now published in a leading international journal. This trial follows on from a longstanding history of important clinical vaccine trials conducted at the MRC Unit The Gambia, and I sincerely thank Ed and the team for the precision and diligence in the conduct of the trial and excellent communication with all the major stakeholders.”
The results of the trial have already been presented to the WHO polio research committee to ensure their impact on global health policy is felt at the earliest possible stage. Much of the same team are now working directly with the WHO in the design and implementation of a pragmatic trial to examine the practical and logistic issues a country might face if it needed to rapidly undertake a widespread community ‘house-to-house’ campaign administering fractional ID doses of IPV to all children under 5 years of age. Such campaigns are likely to be required within the endgame and the data generated in the new trial will complement the results of the published trial indirectly examining questions of implementation.
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The IPV results on http://www.thelancet.com/pdfs/journals/langlo/PIIS2214-109X(16)30075-4.pdf
Polio eradication endgame http://www.polioeradication.org/