Introduction Of Inactivated Poliovirus Vaccine Research Articles

Switch from oral to inactivated poliovirus vaccine in Yogyakarta Province, Indonesia: summary of coverage, immunity, and environmental surveillance.

Inactivated poliovirus vaccine (IPV) is rarely used in tropical developing countries. To generate additional scientific information, especially on the possible emergence of vaccine-derived polioviruses (VDPVs) in an IPV-only environment, we initiated an IPV introduction project in Yogyakarta, an Indonesian province. In this report, we present the coverage, immunity, and VDPV surveillance results. In Yogyakarta, we established environmental surveillance starting in 2004; and conducted routine immunization coverage and seroprevalence surveys before and after a September 2007 switch from oral poliovirus vaccine (OPV) to IPV, using standard coverage and serosurvey methods. Rates and types of polioviruses found in sewage samples were analyzed, and all poliovirus isolates after the switch were sequenced. Vaccination coverage (>95%) and immunity (approximately 100%) did not change substantially before and after the IPV switch. No VDPVs were detected. Before the switch, 58% of environmental samples contained Sabin poliovirus; starting 6 weeks after the switch, Sabin polioviruses were rarely isolated, and if they were, genetic sequencing suggested recent introductions. This project demonstrated that under almost ideal conditions (good hygiene, maintenance of universally high IPV coverage, and corresponding high immunity against polioviruses), no emergence and circulation of VDPV could be detected in a tropical developing country setting.

Affordable inactivated poliovirus vaccine: strategies and progress.

After polio eradication is achieved, the use of live-attenuated oral poliovirus vaccine (OPV) must be discontinued because of the inherent risk of the Sabin strains to revert to neurovirulence and reacquire greater transmissibility that could potentially result in the reestablishment of polio transmission. In 2008, the World Health Assembly mandated that the World Health Organization establish a strategy for developing more-affordable inactivated poliovirus vaccine (IPV) options for low-income countries. In 2012, the Strategic Advisory Group of Experts (SAGE) on Immunization recommended universal IPV introduction as a risk-mitigation strategy before the phased cessation of OPV (starting with Sabin type 2) and emphasized the need for affordable IPV options. In 2013, SAGE reiterated the importance of attaining the long-term target price of IPV at approximately $0.5 per immunizing dose and encouraged accelerated efforts to develop lower-cost IPV options. This article outlines the 4-pronged approach that is being pursued to develop affordable options and provides an update on the current status and plans to make IPV affordable for developing-country use.

Vaccine-associated paralytic poliomyelitis: a review of the epidemiology and estimation of the global burden.

Vaccine-associated paralytic poliomyelitis (VAPP) is a rare adverse event associated with oral poliovirus vaccine (OPV). This review summarizes the epidemiology and provides a global burden estimate. A literature review was conducted to abstract the epidemiology and calculate the risk of VAPP. A bootstrap method was applied to calculate global VAPP burden estimates. Trends in VAPP epidemiology varied by country income level. In the low-income country, the majority of cases occurred in individuals who had received >3 doses of OPV (63%), whereas in middle and high-income countries, most cases occurred in recipients after their first OPV dose or unvaccinated contacts (81%). Using all risk estimates, VAPP risk was 4.7 cases per million births (range, 2.4-9.7), leading to a global annual burden estimate of 498 cases (range, 255-1018). If the analysis is limited to estimates from countries that currently use OPV, the VAPP risk is 3.8 cases per million births (range, 2.9-4.7) and a burden of 399 cases (range, 306-490). Because many high-income countries have replaced OPV with inactivated poliovirus vaccine, the VAPP burden is concentrated in lower-income countries. The planned universal introduction of inactivated poliovirus vaccine is likely to substantially decrease the global VAPP burden by 80%-90%.

The new polio eradication end game: rationale and supporting evidence.

Polio eradication requires the removal of all polioviruses from human populations, whether wild poliovirus or those emanating from the oral poliovirus vaccine (OPV). The Polio Eradication & Endgame Strategic Plan 2013-2018 provides a framework for interruption of wild poliovirus transmission in remaining endemic foci and lays out a plan for the new polio end game, which includes the withdrawal of Sabin strains, starting with type 2, and the introduction of inactivated poliovirus vaccine, for risk mitigation purposes. This report summarizes the rationale and evidence that supports the policy decision to switch from trivalent OPV to bivalent OPV and to introduce 1 dose of inactivated poliovirus vaccine into routine immunization schedules, and it describes the proposed implementation of this policy in countries using trivalent OPV.

ポリオウイルスワクチン

To avoid the risk of vaccine-associated paralytic poliomyelitis (VAPP) and polio outbreaks due to circulating vaccine-derived polioviruses, an inactivated poliovirus vaccine (IPV) was introduced for routine immunization in a number of countries with a low risk of polio outbreaks. Currently, production and marketing of a standalone conventional IPV and two diphtheria-pertussis-tetanus-IPV (Sabin-derived IPV; sIPV) products have been submitted, and it is expected that the IPV products will be introduced in Japan in the autumn of 2012. At the same time, a decline in the OPV immunization rate became apparent in Japan due to serious public concerns about a remaining risk of VAPP and introduction of IPV in the near future. Therefore, the recent development of polio immunity gaps should be carefully monitored, and surveillance of suspected polio cases and laboratory diagnosis of polioviruses have to be intensified for the transition period from OPV to IPV in Japan. The development of sIPV is one of the most realistic options to introduce affordable IPV to developing countries. In this regard, further clinical studies on its efficacy, safety, and interchangeability of sIPV will be needed after the introduction of the sIPV products, which will be licensed in Japan for the first time in the world.

Vacina contra poliomielite: um novo paradigma

OBJETIVO: Analisar as estratégias propostas pela Organização Mundial da Saúde (OMS) para controle da poliomielite. FONTES DE DADOS: Levantamento das publicações sobre poliomielite indexadas no Medline, Lilacs e sites da OMS e Ministério da Saúde de janeiro de 2000 a dezembro de 2006. SÍNTESEDOS DADOS: O reconhecimento da paralisia associada aos vírus vacinais e por vírus circulantes derivados da vacina oral não deixa dúvidas de que, em breve, será necessário interromper o uso da vacina oral para poliomielite. Após os vírus selvagens serem erradicados, a vacina oral para poliomielite deverá ser interrompida, de preferência de forma sincronizada em todos os países. Após a interrupção da vacinação, as populações voltarão a ser suscetíveis à poliomielite, podendo ocorrer surtos da doença por vírus selvagens (escape dos laboratórios de forma acidental ou por bioterrorismo). Nos países que já utilizam a vacina para poliomielite com vírus inativado é pouco provável que haja interrupção da vacinação. Países que atualmente utilizam exclusivamente a vacina oral ficarão na dependência da vigilância epidemiológica e dos estoques de vacina oral para controlar eventuais surtos de pólio. Se a vacina oral para poliomielite for reintroduzida nessas populações, haverá novamente o risco de paralisia associada aos vírus vacinais e por vírus circulantes derivados da vacina oral, que podem se disseminar rapidamente para outras regiões e países vizinhos. CONCLUSÕES: É necessário planejar a introdução da vacina para poliomielite com vírus inativado no calendário de rotina brasileiro, assim como adquirir tecnologia para sua produção, que atualmente é insuficiente para as necessidades globais.

What Role for Inactivated Poliovirus Vaccine in the Eradication Endgame?

The 15-decade drive to control and eradicate polio through immunization [1] has benefited from the availability of 2 excellent vaccines, the inactivated poliovirus vaccine (IPV) of Salk and colleagues, licensed in 1955, and the live attenuated oral poliovirus vaccine (OPV) of Sabin, licensed in 1961. The 2 vaccines have complementary advantages, and both have played—and continue to play—important roles in polio control. IPV has been used primarily in developed countries with good sanitation and temperate climates, whereas OPV has been the primary weapon in the World Health Organization (WHO) initiative to eradicate polio from the developing world [2, 3]. The introduction of IPV in the United States and other high-income developed countries was followed by a sharp decline in polio incidence, but IPV was gradually replaced by OPV in the early 1960s, with only The Netherlands, Nordic countries, and some Canadian provinces continuing exclusive use of IPV. OPV offers the promise of global polio eradication because of its efficient induction of intestinal immunity, ease of administration, suitability for mass immunization campaigns, and lower cost. Great strides have been made toward the goal of global polio eradication, with the apparent eradication of wild poliovirus type 2 in 1999 [4]; the highly localized endemic circulation of wild poliovirus type 3 to pockets in southern Afghanistan, northern India, and northern Nigeria; and the dramatic progress in the control of wild poliovirus type 1 in Egypt and southern Asia (updates are posted on the WHO Web site, http://www.polioeradication .org/). The incidence of polio has declined from an estimated 350,000 cases in 1988 to 1948 cases in 2005. However, wild poliovirus type 1 from reservoirs in northern Nigeria, where polio immunization had been interrupted in 2003 and 2004, spread to 18 previously polio-free countries in 2003‐2005, from Guinea in the west, to Yemen and Somalia in the Horn of Africa, to Indonesia at the southeastern edge of Asia, resulting in a steep increase in the number of cases last year [5]. Nationwide mass immunization campaigns with OPV have rolled back polio in most of these countries, but outbreaks continue in Indonesia, Somalia, and Ethiopia, while northern Nigeria remains an active reservoir for poliovirus types 1 and 3.

Isolation of vaccine-derived type 1 polioviruses displaying similar properties to virulent wild strain Mahoney from sewage in Japan.

Type 1, 2, and 3 vaccine-derived polioviruses were isolated from a sewage disposal plant located downstream of the Oyabe River in Toyama Prefecture, Japan, between October 1993 and September 1995. Neurovirulence was analyzed in 13 type 1 vaccine-derived strains, using mutant analysis by polymerase chain reaction and restriction enzyme cleavage (MAPREC). Nine strains (69%) were estimated to have marked neurovirulence. Some of the neutralizing antigenic sites, temperature sensitivity, and plaque-forming ability of two virulent vaccine-derived poliovirus strains were similar to Mahoney strain. The neutralizing activity of human sera obtained after oral poliomyelitis vaccine (OPV) administration against one of the virulent vaccine-derived polioviruses was examined. Although all human sera showed sufficient neutralizing activity for the prevention of poliomyelitis by vaccine-derived poliovirus strains, a lower titer than that against Sabin type 1 strain was observed. Vaccination against virulent vaccine-derived poliovirus will be effective. However, the environmental presence of viruses that have properties similar to those Mahoney strain is a threat. The introduction of inactivated poliovirus vaccine (IPV), and well-maintained herd immunity, together with reinforced environmental surveillance is important for the final phase of the polio eradication program by the World Health Organization (WHO).

Inactivated poliovirus vaccine and the final stages of poliovirus eradication

The use of the inactivated poliovirus vaccine (IPV) will increase before and probably also after the global eradication of the wild type poliovirus. Before eradication, the switch from the use of oral poliovirus vaccine (OPV) to IPV has been due to the better safety record of IPV. Introduction of IPV in the regular immunisation schedules is made easier by the development of several combination vaccines, including IPV. Maternal antibodies and young age, often considered problematic for early initiation of IPV schedules, did not compromise optimal maintenance of seropositivity during infancy or long-term persisting antibody levels in our studies. OPV-derived, potentially pathogenic and transmissible poliovirus strains, excreted by some individuals for years, may present a problem for a blunt stopping of all polio immunisations after eradication. Our recent results suggest that locally excreted IgA might have a role in the elimination of poliovirus infection in the intestinal tissues.

Introduction of inactivated poliovirus vaccine recommended in US

Introduction of inactivated poliovirus vaccine recommended in US