Protecting investments in polio eradication: the past, present and future of surveillance for acute flaccid paralysis

In September 2003 a WHO consultation group on vaccine-derived polioviruses (VDPV) concluded that in order to prevent future generations of paralytic polio after interruption of transmission of wild poliovirus, the use of trivalent oral polio vaccine (OPV) must be stopped [1]. Another important global policy decision along the road to polio eradication thus became possible – cessation of OPV use at some time after eradication. The question now is not whether OPV must be stopped, but rather when.

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Post-polio eradication: vaccination strategies and options for India

Healthcare in Low-resource Settings ◽

10.4081/hls.2014.1978 ◽

2014 ◽

Vol 2 (2) ◽

Author(s):

Jayakrishnan Thayyil ◽

Thejus Jayakrishnan

Keyword(s):

International Health ◽

Main Tool ◽

Oral Polio Vaccine ◽

Polio Eradication ◽

World Health ◽

Wild Poliovirus ◽

Polio Vaccine ◽

Vaccination Strategies ◽

Health Agencies ◽

Health Organization

In 1988, the World Health Organization (WHO) resolved to eradicate poliomyelitis globally. Since then, the initiative has reported dramatic progress in decreasing the incidence of poliomyelitis and limiting the geographical extent of transmission. 2013 is recorded as the second consecutive year not reporting wild poliovirus (WPV) from India. If the country can retain this position for one more year India will be declared as polio eradicated. What should be the future vaccination strategies? We searched and reviewed the full text of the available published literature on polio eradication via PubMed and examined Internet sources and websites of major international health agencies. The oral polio vaccine (OPV) has been the main tool in the polio eradication program. Once WPV transmission is interrupted, the poliomyelitis will be caused only by OPV. India could expect 1 vaccine-associated paralytic polio per 4.2-4.6 million doses of OPV. Considering the threat of vaccine-derived viruses to polio eradication, WHO urged to develop a strategy to safely discontinue OPV after certification. The ultimate aim is to stop OPV safely and effectively, and eventually substitute with inactivated polio vaccine (IPV). The argument against the use of IPV is its cost. From India, field based data were available on the efficacy of IPV, which was better than OPV. IPV given intradermally resulted in seroconversion rates similar to full-dose intramuscular vaccine. The incremental cost of adopting IPV to replace OPV is relatively low, about US $1 per child per year, and most countries should be able to afford this additional cost.

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Efforts Towards Polio Eradication in Madagascar: 1997 to 2017

Journal of Immunological Sciences ◽

10.29245/2578-3009/2021/s2.1102 ◽

2021 ◽

Vol Special Issue (2) ◽

pp. 102-111

Author(s):

Marcellin Mengouo Nimpa ◽

Noëline Ravelomanana Razafiarivao ◽

Annick Robinson ◽

Mamy Randriatsarafara Fidiniaina ◽

Richter Razafindratsimandresy ◽

...

Keyword(s):

Health System ◽

Oral Polio Vaccine ◽

Polio Eradication ◽

Routine Immunization ◽

World Health ◽

Political Commitment ◽

African Region ◽

Wild Poliovirus ◽

Polio Vaccine ◽

Free Status

Background: In 1988, the World Health Assembly launched the Global Polio Eradication Initiative. WHO AFRO is close to achieve this goal with the last wild poliovirus detected in 2014 in Borno States in Nigeria. The certification of the WHO African Region requires that all the 47 member states meet the critical indicators for a polio free status. Madagascar started implementing polio eradication activities in 1996 and was declared polio free in June 2018 in Abuja. This study describes the progress achieved towards polio eradication activities in Madagascar from 1977- 2017 and highlights the remaining challenges to be addressed. Methods: Data were collected from the national routine immunization services, Country Acute Flaccid surveillance databases and national reports of SIAS and Mop Up campaign. Country complete polio and immunization related documentation provided detailed historical information’s. Results: From 1997 to 2017, Madagascar reported one wild poliovirus (WPV) outbreak and four circulating Vaccine Derived Polio Virus (cVDPV) oubreaks with a total of 21 polioviruses (1 WPV and 21 cVDPV). The last WPV and cVDPV were notified in 1997 in Antananarivo and 2015 in Sakaraha health districts respectively. Madagascar met the main polio surveillance indicators over the last ten years and made significant progress following the last cVDPV2 outbreak in 2014 -2015. In addition, the country successfully implemented the switch from trivalent Oral Polio Vaccine (tOPV) to bivalent Oral Polio vaccine (bOPV) and containment activities. Environmental Surveillance established since 2015 did not reveal any poliovirus. The administrative coverage of the 3rd dose of oral polio vaccine (OPV3) varied across the years from 55% in 1991 to a maximum of 95% in 2007 before a progressive decrease to 86% in 2017. The percentage of AFP cases with more than 3 doses of oral polio vaccines increased from 56% in 2014 to 88% in 2017. A total of 19 supplementary immunization activities (SIA) were conducted in Madagascar from 1997 to 2017, among which 3 were subnational immunization days (sNID) and 16 were national immunization days (NIDs). Poor routine coverage contributed to the occurrence of cVDPC outbreaks in the country; addressing this should remain a key priority for the country to maintain the polio free status. From 2015 to June 2017, Madagascar achieved the required criteria leading to the acceptance of the country’s polio-free documentation in June 2018 by ARCC. However, continuous efforts will be needed to maintain a highly sensitive polio surveillance system with emphasis on security compromised areas. Finally strengthening the health system and governance at all levels will be necessary if these achievements are to be sustained. Conclusions: High national political commitment and support of the Global Polio Eradication Partnership were critical for Madagascar to achieve polio free status. Socio-political instability, weakness of the health system, sub-optimal routine immunization performance, insufficient SIA quality and existing security compromised areas remain critical program challenges to address in order to maintaining the polio free status. Continuous high-level advocacy should be kept in order to ensure that new government authorities maintain polio eradication among the top priorities of the country.

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The polio endgame: rationale behind the change in immunisation

Archives of Disease in Childhood ◽

10.1136/archdischild-2016-311171 ◽

2017 ◽

Vol 102 (4) ◽

pp. 362-365 ◽

Cited By ~ 3

Author(s):

Julie Garon ◽

Manish Patel

Keyword(s):

Scale Up ◽

Oral Polio Vaccine ◽

Polio Eradication ◽

World Health ◽

Routine Immunisation ◽

Wild Poliovirus ◽

Polio Vaccine ◽

Global Coordination ◽

Eradicate Polio

The decades long effort to eradicate polio is nearing the final stages and oral polio vaccine (OPV) is much to thank for this success. As cases of wild poliovirus continue to dwindle, cases of paralysis associated with OPV itself have become a concern. As type-2 poliovirus (one of three) has been certified eradicated and a large proportion of OPV-related paralysis is caused by the type-2 component of OPV, the World Health Assembly endorsed the phased withdrawal of OPV and the introduction of inactivated polio vaccine (IPV) into routine immunisation schedules as a crucial step in the polio endgame plan. The rapid pace of IPV scale-up and uptake required adequate supply, planning, advocacy, training and operational readiness. Similarly, the synchronised switch from trivalent OPV (all three types) to bivalent OPV (types 1 and 3) involved an unprecedented level of global coordination and country commitment. The important shift in vaccination policy seen through global IPV introduction and OPV withdrawal represents an historical milestone reached in the polio eradication effort.

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Moving from oral poliovirus vaccine to inactivated poliovirus vaccine: The rationale and challenges

Bangladesh Journal of Medicine ◽

10.3329/bjm.v31i1.44749 ◽

2019 ◽

Vol 31 (1) ◽

pp. 22-28 ◽

Cited By ~ 1

Author(s):

Kazi Zulfiquer Mamun ◽

Nabeela Mahboob ◽

Kazi Taib Mamun ◽

Hasina Iqbal

Keyword(s):

Oral Polio Vaccine ◽

Sole Source ◽

Polio Eradication ◽

Oral Poliovirus Vaccine ◽

Routine Immunization ◽

Inactivated Polio Vaccine ◽

Polio Vaccine ◽

The Past ◽

Global Polio Eradication Initiative

Oral polio vaccine (OPV) has served as the cornerstone of polio eradication efforts over the past 30 years, trivalent inactivated polio vaccine (IPV) has re-ascended to prominence in the past year, now acting as the sole source of protective immunity against type 2 poliovirus in routine immunization programmes. The Polio Eradication and Endgame Strategic plan 2013–2018, developed by the Global Polio Eradication Initiative (GPEI) outlines the phased removal of OPVs, starting with type 2 poliovirus–containing vaccines and introduction of inactivated polio vaccine in routine immunization to mitigate against risk of vaccine-associated paralytic polio and circulating vaccine-derived poliovirus. Bangladesh J Medicine Jan 2020; 31(1) : 22-28

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Assessing the stability of polio eradication after the withdrawal of oral polio vaccine

10.1101/084012 ◽

2016 ◽

Author(s):

Michael Famulare ◽

Christian Selinger ◽

Kevin A. McCarthy ◽

Philip A. Eckhoff ◽

Guillaume Chabot-Couture

Keyword(s):

Transmission Rate ◽

Oral Polio Vaccine ◽

Polio Eradication ◽

Paralytic Poliomyelitis ◽

Wild Poliovirus ◽

Susceptibility To Infection ◽

Polio Vaccine ◽

High Transmission ◽

Population Immunity ◽

The Stability

AbstractThe oral polio vaccine (OPV) contains live-attenuated polioviruses that induce immunity by causing low virulence infections in vaccine recipients and their close contacts. Widespread immunization with OPV has reduced the annual global burden of paralytic poliomyelitis by a factor of ten thousand or more and has driven wild poliovirus (WPV) to the brink of eradication. However, in instances that have so far been rare, OPV can paralyze vaccine recipients and generate vaccine-derived polio outbreaks. To complete polio eradication, OPV use should eventually cease, but doing so will leave a growing population fully susceptible to infection. If poliovirus is reintroduced after OPV cessation, under what conditions will OPV vaccination be required to interrupt transmission? Can conditions exist where OPV and WPV reintroduction present similar risks of transmission? To answer these questions, we built a multiscale mathematical model of infection and transmission calibrated to data from clinical trials and field epidemiology studies. At the within-host level, the model describes the effects of vaccination and waning immunity on shedding and oral susceptibility to infection. At the between-host level, the model emulates the interaction of shedding and oral susceptibility with sanitation and person-to-person contact patterns to determine the transmission rate in communities. Our results show that inactivated polio vaccine is sufficient to prevent outbreaks in low transmission rate settings, and that OPV can be reintroduced and withdrawn as needed in moderate transmission rate settings. However, in high transmission rate settings, the conditions that support vaccine-derived outbreaks have only been rare because population immunity has been high. Absent population immunity, the Sabin strains from OPV will be nearly as capable of causing outbreaks as WPV. If post-cessation outbreak responses are followed by new vaccine-derived outbreaks, strategies to restore population immunity will be required to ensure the stability of polio eradication.Author SummaryOral polio vaccine (OPV) has played an essential role in the elimination of wild poliovirus (WPV). OPV contains attenuated yet transmissible viruses that can spread from person-to-person. When OPV transmission persists uninterrupted, vaccine-derived outbreaks occur. After OPV is no longer used in routine immunization, as with the cessation of type 2 OPV in 2016, population immunity will decline. A key question is how this affects the potential of OPV viruses to spread within and across communities. To address this, we examined the roles of immunity, sanitation, and social contact in limiting OPV transmission. Our results derive from an extensive review and synthesis of vaccine trial data and community epidemiological studies. Shedding, oral susceptibility to infection, and transmission data are analyzed to systematically explain and model observations of WPV and OPV circulation. We show that in high transmission rate settings, falling population immunity after OPV cessation will lead to conditions where OPV and WPV are similarly capable of causing outbreaks, and that this conclusion is compatible with the known safety of OPV prior to global cessation. Novel strategies will be required to ensure the stability of polio eradication for all time.

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Towards Polio Eradication in Nigeria: Identifying at Risk Population for Low Oral Polio Vaccine (OPV) Uptake

PEDIATRICS ◽

10.1542/peds.137.supplement_3.389a ◽

2016 ◽

Vol 137 (Supplement 3) ◽

pp. 389A-389A

Author(s):

Oluyemisi O. Falope ◽

Korede K. Adegoke ◽

Chukwudi O. Ejiofor ◽

Nnadozie C. Emechebe ◽

Taiwo O Talabi ◽

...

Keyword(s):

At Risk ◽

Oral Polio Vaccine ◽

Polio Eradication ◽

Risk Population ◽

Polio Vaccine

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Inferring Numbers of Wild Poliovirus Excretors Using Quantitative Environmental Surveillance

Vaccines ◽

10.3390/vaccines9080870 ◽

2021 ◽

Vol 9 (8) ◽

pp. 870

Author(s):

Yuri Perepliotchikov ◽

Tomer Ziv-Baran ◽

Musa Hindiyeh ◽

Yossi Manor ◽

Danit Sofer ◽

...

Keyword(s):

Oral Polio Vaccine ◽

Turnaround Time ◽

Quantitative Detection ◽

Environmental Surveillance ◽

Wild Poliovirus ◽

Polio Vaccine ◽

Kinetic Information ◽

Using Data ◽

Number Of Individuals

Response to and monitoring of viral outbreaks can be efficiently focused when rapid, quantitative, kinetic information provides the location and the number of infected individuals. Environmental surveillance traditionally provides information on location of populations with contagious, infected individuals since infectious poliovirus is excreted whether infections are asymptomatic or symptomatic. Here, we describe development of rapid (1 week turnaround time, TAT), quantitative RT-PCR of poliovirus RNA extracted directly from concentrated environmental surveillance samples to infer the number of infected individuals excreting poliovirus. The quantitation method was validated using data from vaccination with bivalent oral polio vaccine (bOPV). The method was then applied to infer the weekly number of excreters in a large, sustained, asymptomatic outbreak of wild type 1 poliovirus in Israel (2013) in a population where >90% of the individuals received three doses of inactivated polio vaccine (IPV). Evidence-based intervention strategies were based on the short TAT for direct quantitative detection. Furthermore, a TAT shorter than the duration of poliovirus excretion allowed resampling of infected individuals. Finally, the method documented absence of infections after successful intervention of the asymptomatic outbreak. The methodologies described here can be applied to outbreaks of other excreted viruses such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), where there are (1) significant numbers of asymptomatic infections; (2) long incubation times during which infectious virus is excreted; and (3) limited resources, facilities, and manpower that restrict the number of individuals who can be tested and re-tested.

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