The largest outbreak of poliomyelitis ever recorded in Africa (1093 cases) occurred from 1 March to 28 May 1999 in Luanda, Angola, and in surrounding areas. The outbreak was caused primarily by a type-3 wild poliovirus, although type-1 wild poliovirus was circulating in the outbreak area at the same time. Infected individuals ranged in age from 2 months to 22 years; 788 individuals (72%) were y...

BACKGROUND Oral poliovirus vaccine (OPV) results in an ongoing burden of poliomyelitis due to vaccine-associated paralytic poliomyelitis and circulating vaccine-derived polioviruses (cVDPVs). This motivates globally coordinated OPV cessation after wild poliovirus eradication. METHODS We modeled poliovirus transmission and OPV evolution to characterize the interaction between population immuni...

This study evaluated the seroprevalence of poliovirus types 1, 2 and 3 antibodies and vaccination coverage in 780 subjects aged between 7 months and 39 years in Montevideo, Uruguay, where oral polio vaccine (OPV) is used. Antibody titers were measured and seroprotection rates and geometric mean titers (GMTs) were compared among four age groups. Vaccination histories were recorded from documents...

The Middletown Project was undertaken as a combined trial and demonstration of how the Sabin oral poliovirus vaccine could be given on a city-wide, simultaneous or mass basis in an urban American community of approximately 30,000 population. Specific objectives were multiple. They included: the assessment of the immunological effectiveness of this immunizing agent when given in such a setting; ...

Given the progress already made towards the goal of global eradication of poliomyelitis LE (polio), the risk of paralytic poliomyelitis is changing in many geographical areas. Vaccination against polio will need to continue because of the threat of wild poliovirus importation. However, an increasing number of polio-free countries are determining that the risk of paralytic poliomyelitis associat...

This study estimates the risk of vaccine-associated paralytic poliomyelitis (VAPP) in Japan between 1971 and 2000. We acquired data regarding the number of VAPP cases from the website of the Ministry of Health, Labour and Welfare, and we estimated the number of oral poliovirus vaccines (OPV) administered based on the reported immunization data. Risk was calculated as the ratio between the numbe...

Planning, implementing, and evaluating interventions against infectious diseases depend on the nature of the infectious disease; the availability of intervention measures; and logistical, economic, and political constraints. Infectious diseases and vaccine- or drug-based interventions can be loosely categorized by the degree to which the infectious disease and the intervention are well establis...

The live, attenuated oral poliovirus vaccine (OPV) provides a powerful tool for controlling and stopping the transmission of wild polioviruses (WPVs), although the risks of vaccine-associated paralytic polio (VAPP) and circulating vaccine-derived poliovirus (cVDPV) outbreaks exist as long as OPV remains in use. Understanding the dynamics of cVDPV emergence and outbreaks as a function of populat...

Acute flaccid paralysis is the main clinical manifestation of poliomyelitis. Faecal specimens from cases of acute flaccid paralysis in Australia are referred to the National Poliovirus Reference Laboratory for virus culture to determine if poliovirus is the causative agent. Isolations of poliovirus are tested to determine whether they have characteristics of the Sabin oral polio vaccine virus s...