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Pathogens (Basel, Switzerland) Mar 2024A sharp rise in circulating vaccine-derived poliovirus type 2 (cVDPV2) outbreaks in the years following the cessation of routine use of poliovirus type 2-containing oral... (Review)
Review
A sharp rise in circulating vaccine-derived poliovirus type 2 (cVDPV2) outbreaks in the years following the cessation of routine use of poliovirus type 2-containing oral polio vaccine and the trend of seeding new emergences with suboptimal vaccination response during the same time-period led to the accelerated development of the novel oral polio vaccine type 2 (nOPV2), a vaccine with enhanced genetic stability and lower likelihood of reversion to neuroparalytic variants compared to its Sabin counterpart. In November 2020, nOPV2 became the first vaccine to be granted an Emergency Use Listing (EUL) by the World Health Organization (WHO) Prequalification Team (PQT), allowing close to a billion doses to be used by countries within three years after its first rollout and leading to full licensure and WHO prequalification (PQ) in December 2023. The nOPV2 development process exemplifies how scientific advances and innovative tools can be applied to combat global health emergencies in an urgent and adaptive way, building on a collaborative effort among scientific, regulatory and implementation partners and policymakers across the globe.
PubMed: 38668228
DOI: 10.3390/pathogens13040273 -
Current Medicinal Chemistry 2024Immune checkpoint inhibitors (ICIs) have shown unprecedented efficacy in treating many advanced cancers. Although FDA-approved ICIs have shown promising efficacy in... (Review)
Review
Immune checkpoint inhibitors (ICIs) have shown unprecedented efficacy in treating many advanced cancers. Although FDA-approved ICIs have shown promising efficacy in treating many advanced cancers, their application is greatly limited by the low response rate, immune-related adverse events (irAE), and drug resistance. Developing novel ICIs holds great promise to improve the survival and prognosis of advanced cancer patients. T-Cell immunoglobulin and ITIM domain (TIGIT) is an inhibitory receptor expressed on T cells, natural killer (NK) cells, and T regulatory cells. Increasing reports have shown that the disrupting CD155-TIGIT axis could activate the immune system and restore antitumor immune response. This review briefly summarized the role of TIGIT in tumor immune escape and targeting CD155-TIGIT axis drugs in preclinical and clinical trials for cancer immunotherapy.
Topics: Humans; Neoplasms; Immunotherapy; Receptors, Immunologic; Receptors, Virus; Immune Checkpoint Inhibitors; Animals
PubMed: 38666504
DOI: 10.2174/0929867330666230324152532 -
PLoS Pathogens Apr 2024Human enteroviruses are the most common human pathogen with over 300 distinct genotypes. Previous work with poliovirus has suggested that it is possible to generate...
Human enteroviruses are the most common human pathogen with over 300 distinct genotypes. Previous work with poliovirus has suggested that it is possible to generate antibody responses in humans and animals that can recognize members of multiple enterovirus species. However, cross protective immunity across multiple enteroviruses is not observed epidemiologically in humans. Here we investigated whether immunization of mice or baboons with inactivated poliovirus or enterovirus virus-like-particles (VLPs) vaccines generates antibody responses that can recognize enterovirus D68 or A71. We found that mice only generated antibodies specific for the antigen they were immunized with, and repeated immunization failed to generate cross-reactive antibody responses as measured by both ELISA and neutralization assay. Immunization of baboons with IPV failed to generate neutralizing antibody responses against enterovirus D68 or A71. These results suggest that a multivalent approach to enterovirus vaccination is necessary to protect against enterovirus disease in vulnerable populations.
Topics: Animals; Mice; Cross Reactions; Antibodies, Viral; Enterovirus Infections; Poliovirus Vaccine, Inactivated; Vaccines, Virus-Like Particle; Antibodies, Neutralizing; Papio; Humans; Poliovirus; Female; Antibody Formation; Enterovirus; Mice, Inbred BALB C; Enterovirus D, Human
PubMed: 38662650
DOI: 10.1371/journal.ppat.1012159 -
Food and Environmental Virology Apr 2024In Iran, which is at high risk of the Wild Poliovirus (WPV) and Vaccine-Derived Poliovirus (VDPV) importation due to its neighborhood with two polio endemic countries,...
In Iran, which is at high risk of the Wild Poliovirus (WPV) and Vaccine-Derived Poliovirus (VDPV) importation due to its neighborhood with two polio endemic countries, Pakistan and Afghanistan, Environmental Surveillance (ES) was established in November 2017. Sistan-Balouchestan province was chosen for the ES due to its vicinity with Pakistan and Afghanistan. Five sewage collection sites in 4 cities (Zahedan, Zabol, Chabahar and Konarak) were selected in the high-risk areas. Since the establishment of ES in November 2017 till the end of 2023, 364 sewage specimens were collected and analyzed. The ES detected polioviruses which have the highest significance for polio eradication program, that is, Wild Poliovirus type 1 (WPV1) and Poliovirus type 2 (PV2). In April and May 2019, three of 364 (0.8%) sewage specimens from Konarak were positive for imported WPV1. According to phylogenetic analysis, they were highly related to WPV1 circulating in Karachi (Sindh province) in Pakistan. PV2 was also detected in 5.7% (21/364) of the sewage specimens, most of which proved to be imported from the neighboring countries. Of 21 isolated PV2s, 7 were VDPV2, of which 5 proved to be imported from the neighboring countries as there was VDPV2 circulating in Pakistan at the time of sampling, and 2 were ambiguous VDPVs (aVDPV) with unknown source. According to the findings of this study, as long as WPV1 and VDPV2 outbreaks are detected in Iran's neighboring countries, there is a definite need for continuation and expansion of the environmental surveillance.
PubMed: 38658427
DOI: 10.1007/s12560-024-09600-8 -
Archives of Disease in Childhood Apr 2024
Topics: Humans; Poliomyelitis; Poliovirus Vaccine, Inactivated; Poliovirus Vaccine, Oral
PubMed: 38636960
DOI: 10.1136/archdischild-2024-327188 -
Vaccine: X Jun 2024Despite the successes of the Global Polio Eradication Initiative, substantial challenges remain in eradicating the poliovirus. The Sabin-strain (live-attenuated) virus...
BACKGROUND
Despite the successes of the Global Polio Eradication Initiative, substantial challenges remain in eradicating the poliovirus. The Sabin-strain (live-attenuated) virus in oral poliovirus vaccine (OPV) can revert to circulating vaccine-derived poliovirus (cVDPV) in under-vaccinated communities, regain neurovirulence and transmissibility, and cause paralysis outbreaks. Since the cessation of type 2-containing OPV (OPV2) in 2016, there have been cVDPV type 2 (cVDPV2) outbreaks in four out of six geographical World Health Organization regions, making these outbreaks a significant public health threat. Preparing for and responding to cVDPV2 outbreaks requires an updated understanding of how different factors, such as outbreak responses with the novel type of OPV2 (nOPV2) and the existence of under-vaccinated areas, affect the disease spread.
METHODS
We built a differential-equation-based model to simulate the transmission of cVDPV2 following reversion of the Sabin-strain virus in prolonged circulation. The model incorporates vaccinations by essential (routine) immunization and supplementary immunization activities (SIAs), the immunity induced by different poliovirus vaccines, and the reversion process from Sabin-strain virus to cVDPV. The model's outcomes include weekly cVDPV2 paralytic case counts and the die-out date when cVDPV2 transmission stops. In a case study of Northwest and Northeast Nigeria, we fit the model to data on the weekly cVDPV2 case counts with onset in 2018-2021. We then used the model to test the impact of different outbreak response scenarios during a prediction period of 2022-2023. The response scenarios included no response, the planned response (based on Nigeria's SIA calendar), and a set of hypothetical responses that vary in the dates at which SIAs started. The planned response scenario included two rounds of SIAs that covered almost all areas of Northwest and Northeast Nigeria except some under-vaccinated areas (e.g., Sokoto). The hypothetical response scenarios involved two, three, and four rounds of SIAs that covered the whole Northwest and Northeast Nigeria. All SIAs in tested outbreak response scenarios used nOPV2. We compared the outcomes of tested outbreak response scenarios in the prediction period.
RESULTS
Modeled cVDPV2 weekly case counts aligned spatiotemporally with the data. The prediction results indicated that implementing the planned response reduced total case counts by 79% compared to no response, but did not stop the transmission, especially in under-vaccinated areas. Implementing the hypothetical response scenarios involving two rounds of nOPV2 SIAs that covered all areas further reduced cVDPV2 case counts in under-vaccinated areas by 91-95% compared to the planned response, with greater impact from completing the two rounds at an earlier time, but it did not stop the transmission. When the first two rounds were completed in early April 2022, implementing two additional rounds stopped the transmission in late January 2023. When the first two rounds were completed six weeks earlier (i.e., in late February 2022), implementing one (two) additional round stopped the transmission in early February 2023 (late November 2022). The die out was always achieved last in the under-vaccinated areas of Northwest and Northeast Nigeria.
CONCLUSIONS
A differential-equation-based model of poliovirus transmission was developed and validated in a case study of Northwest and Northeast Nigeria. The results highlighted (i) the effectiveness of nOPV2 in reducing outbreak case counts; (ii) the need for more rounds of outbreak response SIAs that covered all of Northwest and Northeast Nigeria in 2022 to stop the cVDPV2 outbreaks; (iii) that persistent transmission in under-vaccinated areas delayed the progress towards stopping outbreaks; and (iv) that a quicker outbreak response would avert more paralytic cases and require fewer SIA rounds to stop the outbreaks.
PubMed: 38617838
DOI: 10.1016/j.jvacx.2024.100476 -
Acta Tropica Jul 2024Alveolar Echinococcosis (AE) is a malignant zoonotic disease caused by Echinococcus multilocularis infection. Considering whether the lesion is accompanied by vascular...
BACKGROUND
Alveolar Echinococcosis (AE) is a malignant zoonotic disease caused by Echinococcus multilocularis infection. Considering whether the lesion is accompanied by vascular invasion (VI) is crucial for treatment strategies. A cost-effective and convenient clinical diagnostic method is urgently needed to supplement current techniques. Consequently, we detected soluble CD155 (sCD155) as a potential biomarker for diagnosing VI in hepatic alveolar echinococcosis (HAE).
METHODS
Blood samples were from 42 AE patients and 49 healthy controls (HCs). Based on the computed tomography (CT) and contrast-enhanced CT, AE patients were further categorized into HAE with VI (VIAE; 27 cases) and HAE without VI (NVAE; 15 cases). The sCD155 concentration was measured by an enzyme-linked immunosorbent assay (ELISA). Correlations between sCD155 expression levels and clinicopathological features of AE patients were analyzed using SPSS and GraphPad Prism software.
RESULTS
The sCD155 concentrations in AE patients were significantly higher than in HCs. The serum sCD155 level significantly differed between the VIAE and NVAE groups. The univariate analysis showed that VI of AE was significantly correlated with the sCD155 level when the sCD155 was greater than 11 ng/mL. After adjusting for potential confounding factors, the multivariable analysis showed that sCD155 had an independent effect on VI of HAE. The receiver operating characteristic (ROC) curve showed that sCD155 could differentially diagnose VI of HAE at the cut-off value of 11.08 ng/mL with an area under the curve (AUC) value of 0.75. The sensitivity and specificity were 74.07 % and 66.67 %, respectively; the positive and negative predictive values were 74.07 % and 60.00 %, respectively.
CONCLUSION
The sCD155 could be a VI biomarker for HAE. Elevated sCD155 levels are indicative of an increased likelihood of concomitant VI in HAE patients, necessitating a thorough evaluation of vascular impairment and the formulation of individualized management strategies.
Topics: Adult; Female; Humans; Male; Middle Aged; Biomarkers; Echinococcosis, Hepatic; Echinococcus multilocularis; Enzyme-Linked Immunosorbent Assay; ROC Curve; Tomography, X-Ray Computed
PubMed: 38604326
DOI: 10.1016/j.actatropica.2024.107203 -
Frontiers in Public Health 2024After trivalent oral poliovirus vaccine (tOPV) cessation, Pakistan has maintained immunity to type 2 poliovirus by administering inactivated polio vaccine (IPV) in...
INTRODUCTION
After trivalent oral poliovirus vaccine (tOPV) cessation, Pakistan has maintained immunity to type 2 poliovirus by administering inactivated polio vaccine (IPV) in routine immunization, alongside monovalent OPV type 2 (mOPV2) and IPV in supplementary immunization activities (SIAs). This study assesses the change in poliovirus type 2 immunity after tOPV withdrawal and due to SIAs with mOPV2 and IPV among children aged 6-11 months.
METHODS
Three cross-sectional sequential serological surveys were conducted in 12 polio high-risk areas of Pakistan. 25 clusters from each geographical stratum were selected utilizing probability proportional to size.
RESULTS
Seroprevalence of type 2 poliovirus was 49%, with significant variation observed among surveyed areas; <30% in Pishin, >80% in Killa Abdullah, Mardan & Swabi, and Rawalpindi. SIAs with IPV improved immunity from 38 to 57% in Karachi and 60 to 88% in Khyber. SIAs with IPV following mOPV2 improved immunity from 62 to 65% in Killa Abdullah, and combined mOPV2 and IPV SIAs in Pishin improved immunity from 28 to 89%. Results also reflected that immunity rates for serotypes 1 and 3 were consistently above 90% during all three phases and across all geographical areas.
CONCLUSION
The study findings highlight the importance of implementing effective vaccination strategies to prevent the re-emergence of poliovirus. Moreover, the results provide crucial information for policymakers working toward achieving global polio eradication.
Topics: Child; Humans; Pakistan; Seroepidemiologic Studies; Cross-Sectional Studies; Poliomyelitis; Poliovirus; Poliovirus Vaccine, Oral; Poliovirus Vaccine, Inactivated
PubMed: 38601488
DOI: 10.3389/fpubh.2024.1384410 -
The Journal of Infectious Diseases Apr 2024Warfare has long impeded vaccination programs in polio-endemic Afghanistan. We aimed to describe progress in access to children under 5, oral polio vaccine (OPV)...
BACKGROUND
Warfare has long impeded vaccination programs in polio-endemic Afghanistan. We aimed to describe progress in access to children under 5, oral polio vaccine (OPV) coverage among children under 5 in nationwide polio campaigns, and polio surveillance performance indicators after the Islamic Republic of Afghanistan collapsed to Taliban forces in August 2021.
METHODS
Trends in the number of wild poliovirus type 1 (WPV1) and circulating vaccine-derived poliovirus type 2 (cVDPV2) cases and surveillance indicators from 2015 to 2023, and trends in the OPV coverage in the November 2020-June 2022 polio campaigns, were described.
RESULTS
From 2015 to mid-July 2020, 74 of 126 (58.7%) WPV1 cases were reported from inaccessible areas. In November 2020, 34.1% of target children under 5 were inaccessible; in November 2021 (the first postchange polio campaign), all were accessible. From November 2020, under-5 OPV coverage of 69.9% rose steadily to 99.9% in the May 2022 campaign. The number of cVDPV cases fell from 308 (2020) to zero (2022). June 2022's house-to-house OPV coverage was 34.2% higher than non-house-to-house modalities. Nonpolio acute flaccid paralysis and stool adequacy rates rose from 18.5/100 000 and 92.6% in 2020 to 24.3/100 000 and 94.4% in 2022, respectively.
CONCLUSIONS
Children's inaccessibility no longer vitiates polio eradication; polio surveillance systems are less likely to miss any poliovirus circulation.
PubMed: 38597896
DOI: 10.1093/infdis/jiae129 -
Indian Pediatrics Apr 2024
Topics: Humans; Poliomyelitis; Global Health; Poliovirus Vaccine, Oral; Disease Eradication; Poliovirus Vaccine, Inactivated
PubMed: 38597106
DOI: No ID Found