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EClinicalMedicine Oct 2023In a previous phase 3 clinical trial, we showed that an inactivated poliovirus vaccine derived from the Sabin strain (sIPV) can induce neutralising antibodies against...
BACKGROUND
In a previous phase 3 clinical trial, we showed that an inactivated poliovirus vaccine derived from the Sabin strain (sIPV) can induce neutralising antibodies against currently circulating and reference wild poliovirus strains. However, the immune persistence of sIPV remains to be evaluated.
METHODS
In this study, 400 participants who were eligible for an early phase 3 clinical trial (Jan 1, 2012-Aug 31, 2014) in Pingle County, GuanXi Province, China, were initially involved in one site. Of the participants in the previous phase 3 clinical trial, sera of 287, 262, 237, and 207 participants were sampled at the ages of 4, 6, 8, and 10 years, respectively, after the prime-boost regimen. Neutralising antibodies against attenuated Sabin strains were detected using these serum samples to determine immune persistence. The serum neutralising antibodies titre of 1:8 against poliovirus types 1, 2, and 3 is considered to be a seroprotection level for polio. The trial is registered at ClinicalTrials.gov, NCT01510366.
FINDINGS
The protective rates against poliovirus types 1, 2, and 3 in the sIPV group were all 100% at 10 years after the booster immunisation, compared with 98.1%, 100%, and 97.1%, respectively, in the wIPV control group after 10 years. After the booster at 18 months, the geometric mean titres (GMTs) of neutralising antibodies against poliovirus types 1, 2, and 3 in the sIPV group were 13,265.6, 7856.7, and 6432.2, respectively, and the GMTs in the control group (inoculated with inactivated poliovirus vaccine derived from wild strain (wIPV)) were 3915.6, 2842.6, and 4982.7, respectively. With increasing time after booster immunisation, the GMTs of neutralising antibodies against poliovirus types 1, 2, and 3 gradually decreased in both the sIPV and wIPV groups. At the age of ten years, the GMTs of neutralising antibodies against poliovirus types 1, 2, and 3 in the sIPV group were 452.3, 392.8, and 347.5, respectively, and the GMTs in the wIPV group 108.5, 154.8, and 229.3, respectively, which were still at a higher-than-protective level (1:8).
INTERPRETATION
Both sIPV and wIPV maintained sufficiently high immune persistence against poliovirus types 1, 2, and 3 for at least 10 years after booster immunisation.
FUNDING
Yunnan Provincial Science and Technology Department, the Bill and Melinda Gates Foundation, the National High-tech Research and Development Program, the National International Science and Technology Cooperation Project, the Yunnan Application Basic Research Project, the Innovation Team Project of Xie He, the Yunnan International Scientific and Technological Cooperation Project, and the Medical and Technology Innovation Project of Xie He.
PubMed: 37745024
DOI: 10.1016/j.eclinm.2023.102151 -
Methods and Protocols Sep 2023Poliomyelitis is a condition of great concern and is endemic in only two countries of the world: Pakistan and Afghanistan. Community mobilization plays a vital role in...
Poliomyelitis is a condition of great concern and is endemic in only two countries of the world: Pakistan and Afghanistan. Community mobilization plays a vital role in raising awareness and can help reduce polio vaccine refusals. The objective of this study will be to decrease polio vaccine refusals and zero-dose vaccines by motivating behavior change through the provision of conditional-collective-community-based incentives (C3Is) based on a reduction in polio vaccine refusals. The project will adopt a pretest/post-test quasi-experimental design with two intervention high-risk union councils (HRUCs) and two control union councils (UCs) of peri-urban (Karachi) and rural (Bannu) settings in Pakistan. A participatory community engagement and demand creation strategy with trust-building community mobilization with C3Is, to reduce vaccine refusals and improve polio immunization coverage in two HRUCs, will be used. These UCs will be divided into clusters based on the polio program framework and community groups will be formed in each cluster. These community groups will carry out awareness activities and will be given serial targets to reduce vaccine refusals and those who qualify will be provided C3Is. The project intends to create a replicable model that the government can integrate within health systems for long-term sustainability until the goal of eradication of poliovirus is achieved. The evaluation will be carried out by an independent data collection and analysis team at baseline and endline (after 12 months of intervention). The trial is registered with linicalTrials.gov with number NCT05721274.
PubMed: 37736966
DOI: 10.3390/mps6050083 -
NPJ Vaccines Feb 2024Trivalent oral poliovirus vaccine (tOPV) has been withdrawn and instead an inactivated poliovirus vaccine (IPV) and bivalent type 1 and type 3 OPV (bOPV) sequential...
Trivalent oral poliovirus vaccine (tOPV) has been withdrawn and instead an inactivated poliovirus vaccine (IPV) and bivalent type 1 and type 3 OPV (bOPV) sequential immunization schedule has been implemented since 2016, but no immune persistence data are available for this polio vaccination strategy. This study aimed to assess immune persistence following different polio sequential immunization schedules. Venous blood was collected at 24, 36, and 48 months of age from participants who had completed sequential schedules of combined IPV and OPV in phase III clinical trials. The serum neutralizing antibody titers against poliovirus were determined, and the poliovirus-specific antibody-positive rates were evaluated. A total of 1104 participants were enrolled in this study. The positive rates of poliovirus type 1- and type 3-specific antibodies among the sequential immunization groups showed no significant difference at 24, 36, or 48 months of age. The positive rates of poliovirus type 2-specific antibody in the IPV-IPV-tOPV group at all time points were nearly 100%, which was significantly higher than the corresponding rates in other immunization groups (IPV-bOPV-bOPV and IPV-IPV-bOPV). Immunization schedules involving one or two doses of IPV followed by bOPV failed to maintain a high positive rate for poliovirus type 2-specific antibody.
PubMed: 38424078
DOI: 10.1038/s41541-024-00831-1 -
NPJ Vaccines Sep 2023There is an increasing burden of circulating vaccine-derived polioviruses (cVDPVs) due to the continued use of oral poliovirus vaccine (OPV). However, the...
There is an increasing burden of circulating vaccine-derived polioviruses (cVDPVs) due to the continued use of oral poliovirus vaccine (OPV). However, the informativeness of routine OPV VP1 sequencing for the early identification of viruses carrying virulence-associated reversion mutations has not been directly evaluated in a controlled setting. We prospectively collected 15,331 stool samples to track OPV shedding from children receiving OPV and their contacts for ten weeks following an immunization campaign in Veracruz State, Mexico and sequenced VP1 genes from 358 samples. We found that OPV was genetically unstable and evolves at an approximately clocklike rate that varies across serotypes and by vaccination status. Overall, 61% (11/18) of OPV-1, 71% (34/48) OPV-2, and 96% (54/56) OPV-3 samples with available data had evidence of a reversion at the key 5' UTR attenuating position and 28% (13/47) of OPV-1, 12% (14/117) OPV-2, and 91% (157/173) OPV-3 of Sabin-like viruses had ≥1 known reversion mutations in the VP1 gene. Our results are consistent with previous work documenting rapid reversion to virulence of OPV and underscores the need for intensive surveillance following OPV use.
PubMed: 37749086
DOI: 10.1038/s41541-023-00740-9 -
Vaccines Apr 2024In 2016, the Global Polio Eradication Initiative (GPEI) recommended the cessation of using type 2 oral poliovirus vaccine (OPV) and OPV, with countries having to switch...
BACKGROUND
In 2016, the Global Polio Eradication Initiative (GPEI) recommended the cessation of using type 2 oral poliovirus vaccine (OPV) and OPV, with countries having to switch from the trivalent to bivalent OPV (bOPV) with the addition of inactivated poliovirus vaccine (IPV) in their routine immunization schedule. The current GPEI strategy 2022-2026 includes a bOPV cessation plan and a switch to IPV alone or a combination of vaccine schedules in the future. The focus of our study was to evaluate the immunogenicity of monovalent OPV type 1 (mOPV1) with IPV and IPV-only schedules.
METHODS
This was a three-arm, multi-center randomized-controlled trial conducted in 2016-2017 in India. Participants, at birth, were randomly assigned to the bOPV-IPV (Arm A) or mOPV1-IPV (Arm B) or IPV (Arm C) schedules. Serum specimens collected at birth and at 14, 18, and 22 weeks old were analyzed with a standard microneutralization assay for all the three poliovirus serotypes.
RESULTS
The results of 598 participants were analyzed. The type 1 cumulative seroconversion rates four weeks after the completion of the schedule at 18 weeks were 99.5% (97.0-99.9), 100.0% (97.9-100.0), and 96.0% (92.0-98.1) in Arms A (4bOPV + IPV), B (4mOPV1 + IPV), and C (3IPV), respectively. Type 2 and type 3 seroconversions at 18 weeks were 80.0% (73.7-85.1), 76.9% (70.3-82.4); 93.2% (88.5-96.1), 100.0% (98.0-100.0); and 81.9% (75.6-86.8), 99.4% (96.9-99.9), respectively, in the three arms.
CONCLUSIONS
This study shows the high efficacy of different polio vaccines for serotype 1 in all three schedules. The type 1 seroconversion rate of mOPV1 is non-inferior to bOPV. All the vaccines provide high type-specific immunogenicity. The program can adopt the use of different vaccines or schedules depending on the epidemiology from time to time.
PubMed: 38675806
DOI: 10.3390/vaccines12040424 -
SSM. Qualitative Research in Health Dec 2023A polio booster campaign targeting all children aged 1-9 was implemented across London between August-December 2022 as part of a national enhanced poliovirus incident...
"We're potentially worsening health inequalities": Evaluating how delivery of the 2022 London polio booster campaign was tailored to Orthodox Jewish families to reduce transmission vulnerability.
A polio booster campaign targeting all children aged 1-9 was implemented across London between August-December 2022 as part of a national enhanced poliovirus incident response. Orthodox Jewish (OJ) children were particularly vulnerable to transmission due to disparities in childhood vaccination coverage and the transnational spread of poliovirus affecting linked populations in New York and Israel. This study aimed to evaluate how the polio booster campaign was tailored to increase uptake and enable access for OJ families in northeast and north central London boroughs, and the impact of the campaign on local-level vaccine inequities. Semi-structured in-depth interviews (n = 36) were conducted with participants involved in the implementation and delivery of the polio booster campaign, and OJ mothers. Site visits (n = 5) were conducted at vaccine clinics, and rapid interviews (n = 26) were held to explore parental perceptions of the poliovirus incident and childhood immunisations. Enablers to vaccination during the campaign included the production of targeted printed communications and offering flexible clinic times in primary care settings or complementary delivery pathways embedded in family-friendly spaces. Barriers included digital booking systems. Mothers reported being aware of the poliovirus incident, but the majority of those interviewed did not feel their children were at risk of contracting polio. Healthcare provider participants raised concerns that the vaccine response had limited impact on reducing disparities in vaccine uptake. While OJ families were recognised as a priority for public health engagement during the poliovirus incident response, this evaluation identified limitations in reducing transmission vulnerability during the booster campaign. Lessons for future campaign delivery include effectively conveying transmission risk and the urgency to vaccinate. Priorities for mitigating vaccine inequities include public engagement to develop messaging strategies and strengthening the capacity of primary care and complementary delivery pathways to serve families with higher-than-average numbers of children.
PubMed: 38169919
DOI: 10.1016/j.ssmqr.2023.100365 -
The role of a genetically stable, novel oral type 2 poliovirus vaccine in the poliomyelitis endgame.Revista Panamericana de Salud Publica =... 2023Poliovirus infection causes paralysis in up to 1 in 200 infected persons. The use of safe and effective inactivated poliovirus vaccines and live attenuated oral...
Poliovirus infection causes paralysis in up to 1 in 200 infected persons. The use of safe and effective inactivated poliovirus vaccines and live attenuated oral poliovirus vaccines (OPVs) means that only two pockets of wild-type poliovirus type 1 remain, in Afghanistan and Pakistan. However, OPVs can revert to virulence, causing outbreaks of circulating vaccine-derived poliovirus (cVDPV). During 2020-2022, cVDPV type 2 (cVDPV2) was responsible for 97-99% of poliomyelitis cases, mainly in Africa. Between January and August 2022, cVDPV2 was detected in sewage samples in Israel, the United Kingdom and the United States of America, where a case of acute flaccid paralysis caused by cVDPV2 also occurred. The Pan American Health Organization has warned that Brazil, the Dominican Republic, Haiti and Peru are at very high risk for the reintroduction of poliovirus and an additional eight countries in Latin America are at high risk, following dropping vaccination rates (average 80% coverage in 2022). Sabin type 2 monovalent OPV has been used to control VDPV2 outbreaks, but its use could also lead to outbreaks. To address this issue, a more genetically stable, novel OPV2 (nOPV2) was developed against cVDPV2 and in 2020 was granted World Health Organization Emergency Use Listing. Rolling out a novel vaccine under the Emergency Use Listing in mass settings to contain outbreaks requires unique local regulatory and operational preparedness.
PubMed: 37405121
DOI: 10.26633/RPSP.2023.99 -
Risk Analysis : An Official Publication... Feb 2024In May 2016, the Global Polio Eradication Initiative (GPEI) coordinated the cessation of all use of type 2 oral poliovirus vaccine (OPV2), except for emergency outbreak...
In May 2016, the Global Polio Eradication Initiative (GPEI) coordinated the cessation of all use of type 2 oral poliovirus vaccine (OPV2), except for emergency outbreak response. Since then, paralytic polio cases caused by type 2 vaccine-derived polioviruses now exceed 3,000 cases reported by 39 countries. In 2022 (as of April 25, 2023), 20 countries reported detection of cases and nine other countries reported environmental surveillance detection, but no reported cases. Recent development of a genetically modified novel type 2 OPV (nOPV2) may help curb the generation of neurovirulent vaccine-derived strains; its use since 2021 under Emergency Use Listing is limited to outbreak response activities. Prior modeling studies showed that the expected trajectory for global type 2 viruses does not appear headed toward eradication, even with the best possible properties of nOPV2 assuming current outbreak response performance. Continued persistence of type 2 poliovirus transmission exposes the world to the risks of potentially high-consequence events such as the importation of virus into high-transmission areas of India or Bangladesh. Building on prior polio endgame modeling and assuming current national and GPEI outbreak response performance, we show no probability of successfully eradicating type 2 polioviruses in the near term regardless of vaccine choice. We also demonstrate the possible worst-case scenarios could result in rapid expansion of paralytic cases and preclude the goal of permanently ending all cases of poliomyelitis in the foreseeable future. Avoiding such catastrophic scenarios will depend on the development of strategies that raise population immunity to type 2 polioviruses.
Topics: Humans; Poliomyelitis; Poliovirus; Poliovirus Vaccine, Oral; Disease Outbreaks; Bangladesh; Global Health
PubMed: 37344376
DOI: 10.1111/risa.14159 -
The Pan African Medical Journal 2023in 2016, a switch from trivalent oral poliovirus vaccine (OPV) (containing serotypes 1,2,3) to bivalent OPV (types 1,3) was implemented globally. We assessed the...
INTRODUCTION
in 2016, a switch from trivalent oral poliovirus vaccine (OPV) (containing serotypes 1,2,3) to bivalent OPV (types 1,3) was implemented globally. We assessed the seroprevalence of poliovirus antibody levels in selected Nigerian states, before and after the switch, documented poliovirus type2 outbreak responses conducted and ascertained factors associated with immunity gaps based on seroprevalence rates.
METHODS
we conducted a secondary analysis of stored serum samples from the 2018 Nigeria National HIV/AIDS Indicator and Impact Survey. Serum from 1,185 children aged 0-119 months residing in one southern and four northern states were tested for serotype-specific PV neutralizing antibodies; seropositivity was a reciprocal titer ≥8. We conducted regression analysis to determine sociodemographic risk factors associated with low seroprevalence using SAS 9.4.
RESULTS
children aged 24-119 months (pre-switch cohort) had seroprevalence against PV1, PV2, and PV3, of 97.3% (95% CI:96.4-98.2), 93.8% (95% CI:92.2-95.5), and 91.3% (95% CI:89.2-93.4), while children aged <24 months (post-switch) had seroprevalence of 86.0% (95% CI:81.2-90.8), 55.6% (95% CI: 47.7-63.4), and 77.2% (95% CI:71.0-83.4) respectively. Regression analysis showed age <24 months was associated with lower seroprevalence against all PV serotypes, (p<0.0001); females had lower seroprevalence against PV1 (p=0.0184) and PV2 (p=0.0354); northern states lower seroprevalence against PV1 (p=0.0039), while well-water source lower seroprevalence against PV3 (p=0.0288).
CONCLUSION
this study showed high seroprevalence rates against PV 1, 2, and 3 in pre-switch children (aged 24-119 months). However, post-switch children (<24 months) had low immunity against PV2 despite outbreak responses. Strategies to increase routine immunization coverage and high-quality polio campaigns can increase immunity against polio virus.
Topics: Child; Female; Humans; Infant; Poliovirus; Antibodies, Viral; Seroepidemiologic Studies; Nigeria; Poliomyelitis; Poliovirus Vaccine, Oral; Poliovirus Vaccine, Inactivated
PubMed: 38370104
DOI: 10.11604/pamj.supp.2023.45.2.38098 -
Vaccine Feb 2024Delays in achieving polio eradication have led to ongoing risks of poliovirus importations that may cause outbreaks in polio-free countries. Because of the low, but...
Trade-offs of different poliovirus vaccine options for outbreak response in the United States and other countries that only use inactivated poliovirus vaccine (IPV) in routine immunization.
Delays in achieving polio eradication have led to ongoing risks of poliovirus importations that may cause outbreaks in polio-free countries. Because of the low, but non-zero risk of paralysis with oral poliovirus vaccines (OPVs), countries that achieve and maintain high national routine immunization coverage have increasingly shifted to exclusive use of inactivated poliovirus vaccine (IPV) for all preventive immunizations. However, immunization coverage within countries varies, with under-vaccinated subpopulations potentially able to sustain transmission of imported polioviruses and experience local outbreaks. Due to its cost, ease-of-use, and ability to induce mucosal immunity, using OPV as an outbreak control measure offers a more cost-effective option in countries in which OPV remains in use. However, recent polio outbreaks in IPV-only countries raise questions about whether and when IPV use for outbreak response may fail to stop poliovirus transmission and what consequences may follow from using OPV for outbreak response in these countries. We systematically reviewed the literature to identify modeling studies that explored the use of IPV for outbreak response in IPV-only countries. In addition, applying a model of the 2022 type 2 poliovirus outbreak in New York, we characterized the implications of using different OPV formulations for outbreak response instead of IPV. We also explored the hypothetical scenario of the same outbreak except for type 1 poliovirus instead of type 2. We find that using IPV for outbreak response will likely only stop outbreaks for polioviruses of relatively low transmission potential in countries with very high overall immunization coverage, seasonal transmission dynamics, and only if IPV immunization interventions reach some unvaccinated individuals. Using OPV for outbreak response in IPV-only countries poses substantial risks and challenges that require careful consideration, but may represent an option to consider for some outbreaks in some populations depending on the properties of the available vaccines and coverage attainable.
Topics: Humans; United States; Poliovirus Vaccine, Inactivated; Poliovirus; Poliovirus Vaccine, Oral; Poliomyelitis; Disease Outbreaks; Vaccination; New York
PubMed: 38218668
DOI: 10.1016/j.vaccine.2023.12.081