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

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vaccine is sufficient to prevent outbreaks in low transmission rate settings, and that OPV can be reintroduced and withdrawn as needed in moderate transmission rate settings.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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Impact of Maternal Antibody on the Immunogenicity of Inactivated Polio Vaccine in Infants Immunized With Bivalent Oral Polio Vaccine: Implications for the Polio Eradication Endgame

Clinical Infectious Diseases ◽

10.1093/cid/ciy649 ◽

2018 ◽

Vol 67 (suppl_1) ◽

pp. S57-S65 ◽

Cited By ~ 4

Author(s):

James T Gaensbauer ◽

Chris Gast ◽

Ananda S Bandyopadhyay ◽

Miguel O’Ryan ◽

Xavier Saez-Llorens ◽

...

Keyword(s):

Oral Polio Vaccine ◽

Polio Eradication ◽

Maternal Antibody ◽

Inactivated Polio Vaccine ◽

Polio Vaccine

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

Epidemiology and Infection ◽

10.1017/s0950268804002638 ◽

2004 ◽

Vol 132 (5) ◽

pp. 779-780 ◽

Cited By ~ 3

Author(s):

D. L. HEYMANN ◽

E. M. DE GOURVILLE ◽

R. B. AYLWARD

Keyword(s):

Acute Flaccid Paralysis ◽

Oral Polio Vaccine ◽

Policy Decision ◽

Polio Eradication ◽

Global Policy ◽

Wild Poliovirus ◽

The Road ◽

Polio Vaccine ◽

The Past ◽

Consultation Group

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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The Pathology of Poliomyelitis and the Vaccines and Nonvaccine Therapy

E3S Web of Conferences ◽

10.1051/e3sconf/202130802018 ◽

2021 ◽

Vol 308 ◽

pp. 02018

Author(s):

Yushuo Chen ◽

Tianrui Yue ◽

Zixiao Zhang

Keyword(s):

Developing Countries ◽

Nervous System ◽

Low Cost ◽

Oral Polio Vaccine ◽

Polio Eradication ◽

Paralytic Poliomyelitis ◽

Strongly Correlated ◽

Inactivated Polio Vaccine ◽

Polio Vaccine ◽

New Type

Poliomyelitis is an exclusively human disease that mainly affects children. Clinical features of poliomyelitis can be varied, from mild illness to the most severe paralysis, and the factor why poliomyelitis has different performances in individuals has been proved strongly correlated with membrane protein CD155. The nervous system shows a special protecting phenomenon against the invasion of poliovirus, and the mechanism is not very clear at present. Vaccines are the main means of preventing and controlling polio, and many different vaccines have been invented in the process of fighting polio. Inactivated polio vaccine (IPV) and oral polio vaccine (OPV) are the two main vaccines. IPV is known for its safety while OPV is widely used in developing countries because of its relatively low cost. This usage also leads to some side effects: vaccine-associated paralytic polio (VAPP) and vaccine-derived poliovirus (VDPV). Now, for polio eradication, the elimination of these two diseases has become particularly important. Thus, a new type of vaccine was created: sequential IPV-OPV with the safety of IPV and the low cost of OPV. This paper will talk about the different polio vaccines and their effects. An enormous difference between people who have gotten the vaccine and people who have not got the vaccine. Comparing the two kinds of people, people who get normal poliovirus, and people who get poliovirus after taking a vaccine, known as VAPP (vaccine-associated paralytic poliomyelitis), the former cannot get full recovery whole life and the latter has a very low possibility. In conclusion, people should take vaccines if it is affordable for them.

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Epidemic poliomyelitis, post-poliomyelitis sequelae and the eradication program

Microbiology Australia ◽

10.1071/ma20053 ◽

2020 ◽

Vol 41 (4) ◽

pp. 196

Author(s):

Margaret M Peel

Keyword(s):

Late Onset ◽

Oral Polio Vaccine ◽

The United States ◽

Polio Eradication ◽

Oral Route ◽

World Health ◽

Paralytic Poliomyelitis ◽

Polio Vaccine ◽

The Central Nervous System ◽

Health Organization

Epidemics of paralytic poliomyelitis (polio) first emerged in the late 19th and early 20th centuries in the United States and the Scandinavian countries. They continued through the first half of the 20th century becoming global. A major epidemic occurred in Australia in 1951 but significant outbreaks were reported from the late 1930s to 1954. The poliovirus is an enterovirus that is usually transmitted by the faecal–oral route but only one in about 150 infections results in paralysis when the central nervous system is invaded. The Salk inactivated polio vaccine (IPV) became available in Australia in 1956 and the Sabin live attenuated oral polio vaccine (OPV) was introduced in 1966. After decades of stability, many survivors of the earlier epidemics experience late-onset sequelae including post-polio syndrome. The World Health Organization launched the global polio eradication initiative (GPEI) in 1988 based on the easily administered OPV. The GPEI has resulted in a dramatic decrease in cases of wild polio so that only Pakistan and Afghanistan report such cases in 2020. However, a major challenge to eradication is the reversion of OPV to neurovirulent mutants resulting in circulating vaccine-derived poliovirus (cVDPV). A novel, genetically stabilised OPV has been developed recently to stop the emergence and spread of cVDPV and OPV is being replaced by IPV in immunisation programs worldwide. Eradication of poliomyelitis is near to achievement and the expectation is that poliomyelitis will join smallpox as dreaded epidemic diseases of the past that will be consigned to history.

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Corrigendum to: Epidemic poliomyelitis, post-poliomyelitis sequelae and the eradication program

Microbiology Australia ◽

10.1071/ma20053_co ◽

2020 ◽

Vol 41 (4) ◽

pp. 223

Author(s):

Margaret M Peel

Keyword(s):

Late Onset ◽

Oral Polio Vaccine ◽

The United States ◽

Polio Eradication ◽

Oral Route ◽

World Health ◽

Paralytic Poliomyelitis ◽

Polio Vaccine ◽

The Central Nervous System ◽

Health Organization

Epidemics of paralytic poliomyelitis (polio) first emerged in the late 19th and early 20th centuries in the United States and the Scandinavian countries. They continued through the first half of the 20th century becoming global. A major epidemic occurred in Australia in 1951 but significant outbreaks were reported from the late 1930s to 1954. The poliovirus is an enterovirus that is usually transmitted by the faecal–oral route but only one in about 150 infections results in paralysis when the central nervous system is invaded. The Salk inactivated polio vaccine (IPV) became available in Australia in 1956 and the Sabin live attenuated oral polio vaccine (OPV) was introduced in 1966. After decades of stability, many survivors of the earlier epidemics experience late-onset sequelae including post-polio syndrome. The World Health Organization launched the global polio eradication initiative (GPEI) in 1988 based on the easily administered OPV. The GPEI has resulted in a dramatic decrease in cases of wild polio so that only Pakistan and Afghanistan report such cases in 2020. However, a major challenge to eradication is the reversion of OPV to neurovirulent mutants resulting in circulating vaccine-derived poliovirus (cVDPV). A novel, genetically stabilised OPV has been developed recently to stop the emergence and spread of cVDPV and OPV is being replaced by IPV in immunisation programs worldwide. Eradication of poliomyelitis is near to achievement and the expectation is that poliomyelitis will join smallpox as dreaded epidemic diseases of the past that will be consigned to history.

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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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Wild and vaccine-derived poliovirus circulation, and implications for polio eradication

Epidemiology and Infection ◽

10.1017/s0950268816002569 ◽

2016 ◽

Vol 145 (3) ◽

pp. 413-419 ◽

Cited By ~ 13

Author(s):

P. L. LOPALCO

Keyword(s):

Wild Strain ◽

Oral Polio Vaccine ◽

Polio Eradication ◽

Poliovirus Type ◽

Polio Vaccine ◽

Vaccine Schedule ◽

Long Time ◽

High Level ◽

Type 3

SUMMARYPolio cases due to wild virus are reported by only three countries in the world. Poliovirus type 2 has been globally eradicated and the last detection of poliovirus type 3 dates to November 2012. Poliovirus type 1 remains the only circulating wild strain; between January and September 2016 it caused 26 cases (nine in Afghanistan, 14 in Pakistan, three in Nigeria). The use of oral polio vaccine (OPV) has been the key to success in the eradication effort. However, paradoxically, moving towards global polio eradication, the burden caused by vaccine-derived polioviruses (VDPVs) becomes increasingly important. In this paper circulation of both wild virus and VDPVs is reviewed and implications for the polio eradication endgame are discussed. Between April and May 2016 OPV2 cessation has been implemented globally, in a coordinated switch from trivalent OPV to bivalent OPV. In order to decrease the risk for cVDPV2 re-emergence inactivated polio vaccine (IPV) has been introduced in the routine vaccine schedule of all countries. The likelihood of re-emergence of cVDPVs should markedly decrease with time after OPV cessation, but silent circulation of polioviruses cannot be ruled out even a long time after cessation. For this reason, immunity levels against polioviruses should be kept as high as possible in the population by the use of IPV, and both clinical and environmental surveillance should be maintained at a high level.

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