Two authors will independently screen the results of the search, select studies, extract data and assess risk of bias. independently screen the results of the search, select studies, extract data and assess risk of bias. We will stratify analyses by study design, type of poliovirus, type of outcome measure and number of IPV doses given. For each type of poliovirus, we will pool the outcome data from studies using random-effects meta-analyses. Statistical heterogeneity will be assessed using the 2 2 test of homogeneity and quantified using the I2 statistic. To investigate statistical heterogeneity, subgroup analyses will be performed based on the timing of the first fractional dose, age of administration, immunisation schedules and country income status. Sensitivity analyses will be used to assess if the effect of IPV fractional dosing is affected by study design, risk of bias and methods of meta-analysis. Ethics and dissemination We obtained approval from the University of Cape Town Human Research Ethics Committee (HREC REF: 412/2018). The findings of this review will provide evidence for decision-making with regards to IPV dosage, eventually improving access to the vaccine by stretching vaccine supplies. The results will be published in the University of Cape Town online library and in a peer reviewed journal. PROSPERO registration number CRD42018092647. strong class=”kwd-title” Keywords: inactivated polio vaccine, fractional dosing, dose-sparing, polio eradication, vaccine shortage, ipv Strengths and limitations of this study We will conduct study selection, data extraction and risk of bias assessment in duplicate to minimise the risk of bias. We will use the Grading of Recommendations Assessment, Development and Evaluation approach to evaluate the certainty of the evidence for each outcome. Since non-randomised studies will be included, we anticipate high risk of selection bias, which will be mitigated by conducting sensitivity analyses. Introduction Poliomyelitis (or polio) is a communicable disease caused by one of three related wild polioviruses: poliovirus types 1, 2 and 3. Infection can occur at any age but it mainly affects children under 5?years of age.1 The virus typically enters the body through the mouth and multiplies inside the gut. Initially, it manifests as flu-like symptoms. Once established, it enters the bloodstream Tesaglitazar and attacks the central nervous system. As it proliferates, it destroys nerve cells which stimulate muscles. These nerve cells cannot be renewed and affected muscles no longer function, causing paralysis. Up to 95% of infected individuals have no symptoms and about 5% who develop minor flu-like symptoms fully recover.2 Paralysis occurs in less than 1% of infected individuals.2 Immunity against polio is acquired following recovery from a natural infection with poliovirus or vaccination with a Rabbit Polyclonal to Mouse IgG polio vaccine. There are two types of polio vaccines, which are highly effective. The first is an injectable vaccine developed in the 1950s (the inactivated polio vaccine?[IPV]) and the second, an oral vaccine developed in the 1960s (the oral polio vaccine?[OPV]).1 In the early 1980s, more than 350 000 cases of paralytic polio were estimated to occur per year worldwide.3 The widespread use of the OPV resulted in substantial advances towards eradicating polio.3C5 However, the vaccine has been linked to vaccine-associated paralytic poliomyelitis (VAPP) and the generation of vaccine-derived polioviruses (VDPVs).6 7 These liabilities threaten the achievement of Tesaglitazar a polio-free world. The Polio Eradication and Endgame Strategic Plan 2013C2018 outlines the necessary steps required to ensure that transmission of both wild polio viruses (WPV) and VDPVs is interrupted. One of its objectives is to prevent the spread and re-emergence of VDPVs by gradually replacing OPV with the IPV. 8 The first stage in the phased removal of OPV was completed in April 2016.9 It involved the cessation of the type 2 component of Tesaglitazar OPV through a global switch from trivalent OPV (containing all three poliovirus types) to bivalent OPV (containing only poliovirus types 1 and 3).8 Prior to switching, in November 2012, the Strategic Advisory Group of Experts on Immunisation recommended the introduction of Tesaglitazar at least one dose of IPV in national immunisation schedules to mitigate the risk of re-introduction or re-emergence of WPV type?2 or VDPV type 2.10 This minimum dose was meant to provide an immune base to improve immune response and lower the risk of paralysis in the event of a type?2 polio outbreak.3.
Two authors will independently screen the results of the search, select studies, extract data and assess risk of bias