Nucleotide variation in Sabin type 3 poliovirus from an Albanian infant with agammaglobulinemia and vaccine associated poliomyelitis

Vaccine-associated paralytic poliomyelitis in oral polio vaccine recipients: disproportionality analysis using VAERS and systematic review

BACKGROUND

Vaccine-associated paralytic poliomyelitis (VAPP) is a rare adverse event of oral poliovirus vaccines (OPV), particularly affecting immunodeficient individuals.

RESEARCH DESIGN AND METHODS

This study aimed to (1) Assess the association between OPV and VAPP using Vaccine Adverse Event Reporting System (VAERS) database (2) Outline patient characteristics and risk factors associated with the occurrence of VAPP in OPV recipients through a systematic review of case reports and case series. A disproportionality analysis was conducted using the data from VAERS, encompassing adverse events reported from 1990 till February 2023. Additionally, we conducted a systematic review of case reports and case series using PubMed, Scopus, and Embase databases.

RESULTS

The VAERS data revealed 130 VAPP reports among 1,739,903 OPV linked adverse events, with year 2010 reporting the strongest association. The systematic review of 37 studies highlighted VAPP occurrence within 2 months to 4 years post-vaccination, typically with acute flaccid paralysis. Immunodeficiency and perianal abscess emerged as major risk factors. Out of the 37 included studies, 27 showed consistent causal association of VAPP with OPV using WHO-AEFI causality assessment tool.

CONCLUSION

The study emphasized the seriousness of VAPP and highlights its association with OPV, identifying immunodeficiency as a prominent contributor to VAPP manifestation.

Prevalence of poliovirus neutralizing antibodies in Italian population: A systematic review and meta-analysis

INTRODUCTION

The introduction of anti-poliomyelitis vaccines has driven progress toward the global eradication of wild polioviruses, a millennium goal of the World Health Organization. With the vaccination campaigns carried out since 1964, in 2002 Italy was certified polio-free, considering that no cases had been recorded since 1983. Nevertheless, it is crucial to guarantee high level of immunization coverage also in low-endemicity countries, considering that sporadic polio cases can be recorded. To evaluate the presence of susceptible subjects in the population, seroepidemiological studies are key actions.

METHODS

We conducted a systematic review of the relevant literature to evaluate the prevalence of anti-PV neutralizing antibodies in Italian population. Seven studies, selected among scientific articles available in MEDLINE/PubMed, ISI Web of Knowledge and Scopus and published from January 1, 2012, to November 15, 2022, were included.

RESULTS

The pooled prevalence of subjects without PV1 neutralizing antibodies was 6.4% (95%CI = 0.5-16.9), for PV2 it was 5.3% (95%CI = 0.4-14.2), and for PV3 it was 13.0% (95%CI = 4.0-25.7; I2 = 98.5%). Levels of neutralizing antibodies appears to decrease with increasing age; this decline is a proxy for the real risk factor, which is the time since the last vaccine dose.

CONCLUSIONS

Public health institutions must be aware of the risk of reintroduction of wild PV in polio-free countries and therefore they must keep high level of immunization in population and reinforce the active surveillance systems.

Poliomyelitis is a current challenge: long-term sequelae and circulating vaccine-derived poliovirus

For more than 20 years, the World Health Organization Western Pacific Region (WPR) has been polio-free. However, two current challenges are still polio-related. First, around half of poliomyelitis elderly survivors suffer late poliomyelitis sequelae with a substantial impact on daily activities and quality of life, experiencing varying degrees of residual weakness as they age. The post-polio syndrome as well as accelerated aging may be involved. Second, after the worldwide Sabin oral poliovirus (OPV) vaccination, the recent reappearance of strains of vaccine-derived poliovirus (VDPV) circulating in the environment is worrisome and able to persistent person-to-person transmission. Such VDPV strains exhibit atypical genetic characteristics and reversed neurovirulence that can cause paralysis similarly to wild poliovirus, posing a significant obstacle to the elimination of polio. Immunization is essential for preventing paralysis in those who are exposed to the poliovirus. Stress the necessity of maintaining high vaccination rates because declining immunity increases the likelihood of reemergence. If mankind wants to eradicate polio in the near future, measures to raise immunization rates and living conditions in poorer nations are needed, along with strict observation. New oral polio vaccine candidates offer a promissory tool for this goal.

Pediatric case with vaccine-related poliovirus infection: A case report

BACKGROUND

As long as oral poliovirus vaccine (OPV) is used, the potential risk for the emergence of vaccine-related polioviruses remains.

CASE SUMMARY

We report a case of Sabin-like type 1 poliovirus infection in an immunocompetent 17-mo-old child after receiving four scheduled doses of OPV. Somehow, the four doses did not confer full protection, possibly because of interference created by other enteroviruses.

CONCLUSION

The surveillance of vaccine-related polioviruses has important implications for improving health policies and vaccination strategies. Missed cases of vaccine-related poliovirus infection might pose a potential risk to global poliovirus eradication. Therefore, the global withdrawal of OPV and a shift to the inclusion of only inactivated poliovirus vaccine in the vaccination schedule is the main objective of the polio eradication program.

Gene Polymorphisms Increasing the Risk of Intracranial Aneurysms: Interleukin-6 -174G>C and -572G>C (Part II)

Introduction The interleukin-6 (IL-6), a proinflammatory cytokine, supports the adaptive immune response and regulates inflammatory processes. The -174 G>C and -572 G>C promoter polymorphisms of the IL-6 gene take part in the pathogenesis of intracranial aneurysms (IAs) and influence the clinical presentation of subarachnoid hemorrhage. This meta-analysis purposes to evaluate whether and which IL-6 allelic variations are related to a risk of IAs formation. Methods A PRISMA-based literature search was performed on the PubMed/Medline and Web of Science databases. The keywords used were "interleukin-6," "IL-6," "polymorphism," "interleukin-6 genotype," combined with "intracranial aneurysms" and "subarachnoid hemorrhage." Only human case-control studies, with a study (IAs) and a control group, written in English, and published in the last 15 years were selected. A meta-analysis was performed, estimating odds ratios and 95% confidence intervals in fixed- or random-effects models, as applicable. Statistical analysis was conducted with RevMan 5.0 software. Results 9 studies were eligible. No associations were found between -174 G>C polymorphisms and IAs susceptibility. Notable results were reported by the analysis of -572G>C polymorphisms. -572GG/GC/CC genotypes were strongly related to IAs occurrence with a statistical significance of p=0.03, p=0.0009, and p=0.00001, respectively. Conclusion A higher incidence of -572G>C promoter polymorphisms were demonstrated in the IAs group, highlighting the pivotal role of inflammatory genes in the natural history of brain aneurysms. Additional studies are required considering the racial heterogenicity and the need to widen the population sample.

Gene Polymorphisms Increasing the Risk of Intracranial Aneurysms: Interleukin-1β -511C>T (Part I)

Introduction Intracranial aneurysms (IAs) are devastating cerebrovascular diseases with multifactorial etiology. The role of inflammation is indisputable, and interleukins are pivotal in supporting local inflammatory pathways and endothelial dysfunction at the aneurysm wall. In the light of insufficient evidence reported in the literature, this meta-analysis was aimed to investigate the genetic linkage between IL-1β (rs16944) -511C>T polymorphisms and IAs susceptibility. Methods A comprehensive online literature review was completed using the PubMed/Medline and Web of Science databases in accordance with the PRISMA guidelines. "Interleukin-1β," "IL-1β," "polymorphism," "intracranial aneurysm," and "subarachnoid hemorrhage" were the main keywords. Only human case-control studies, published from 2005 to 2021, written in English or translated, were screened. In the statistical analysis, we applied the fixed- and random-effect models, according to the level of heterogeneity, to assess the odds ratios (ORs) and 95% confidence intervals (CIs). RevMan 5.0 software was used for the statistics. Results Only 4 studies were eligible, with a total of 2070 patients, 1050 of which were assigned to the study group. Combined results showed a statistically significant association between the risk of IAs and -511CC (OR=0.79, 95% CI [0.65-0.95], p=0.01), and CT (OR=0.69, 95% CI [0.58-0.82], p<0.0001; OR=0.71, 95% CI [0.55-0.93], p=0.01) allele variations, both in the fixed- and random- models. No correlation was identified for the -511TT genotype (p=0.42; p=0.78). All the texts showed a low level of publication bias. Conclusion The present meta-analysis proved a potential role of IL-1β -511CC/CT genotypes in the pathogenesis of IAs. Additional studies are imperative to explain the underlying neuroimmune mechanisms, also allowing tailoring the potential inflammatory-target therapies for IAs.

Human Herpes Virus 7-related encephalopathy in children

BACKGROUND

Primary HHV7 infection is almost ubiquitous, and it can present as exanthema subitem. Little is known on the clinical relevance of HHV7 neuroinvasion in immunocompetent children.

METHODS

We describe 12 patients (median age 9.45 years, 50% males) with acute encephalopathy and active HHV7 infection. In all patients, HHV7-DNA was detected on cerebrospinal fluid (CSF) by RT-PCR.

RESULTS

7/12 patients had meningoencephalitis (two with ADEM and one with MOG antibody-associated CIS); 5/12 showed acute neuropsychiatric symptoms. EEG showed anomalies exclusively in patients with meningoencephalitis. Six patients had RMN anomalies. CSF HHV7 copies ranged between 20 and 3,500 copies/mL (median 66 copies/mL) and mean HHV7 CSF/blood ratio was 0.75. Outcome was favorable in all children, although 3/12 had minor neurobehavioral sequelae. Mean follow-up period of 5.2 months.

CONCLUSIONS

HHV7 can determine neuroinvasion in immunocompetent children, leading to acute encephalopathy. Blood-brain barrier damage and high CSF/blood viral copies ratio correlated with a more severe presentation. We speculate on the importance of immune-mediated mechanisms in provoking clinical features.

Investigation Report of cVDPV2 Outbreak in Bokh Woreda of Dollo Zone, Somali Regional State, Ethiopia

Background

Poliovirus isolates detected in persons or in the environment can fall into three major categories: wild, Sabin and Sabin-like, or vaccine-derived. Detection of wild or vaccine-derived poliovirus may constitute an emergency, which can be categorized as an event that can lead to an outbreak, depending on characteristics of the isolate and the context in which it appears. The aim of the study was investigation report of cVDPV2 outbreak in Bokh woreda of Dollo Zone, Somali regional state, Ethiopia.

Methods

A team of experts drawn from different organizations was deployed to Bokh woreda to make detailed field investigation from May 25 to June 17, 2019. By using standard World Health Organization polio outbreak investigation checklist, document review of surveillance, immunization, and clinical data related to the case was made. Key informant's interview was made to health professionals, managers, parents of case, woreda and kebele leaders, religious leaders, and HEWs related to acute flaccid paralysis outbreak.

Result

The notified AFP case was a 39-month-old female from Angalo kebele of Bokh woreda, Dollo Zone. On 19th May 2019, the patient developed high grade fever and was taken to Angalo Health Post on 20th May 2019. As per the examination by a health extension worker, the child had high grade fever and neck stiffness with preliminary diagnosis of meningitis for which ceftriaxone injection was prescribed. Contact sample was taken from three children on 28th May 2019 and 29th May 2019 and was sent to Addis Ababa National Polio Laboratory. All contact stool samples were found to be positive for poliovirus type 2 and referred for sequencing in National Institute of Communicable Diseases (NICD), South Africa, the Regional Polio Reference Laboratory. Conclusion and Recommendation. The clinical presentation of the cases is compatible with poliovirus infection, improving the quality and coverage of supplementary polio immunization activities through proper planning; strict supervision and follow-up can reduce the occurrence of acute flaccid paralysis.

Acute Flaccid Myelitis: Current Status and Diagnostic Challenges

Acute flaccid myelitis (AFM) is a sudden-onset polio-like neuromuscular disability found commonly in young children. There is an increasing incidence of confirmed AFM cases in the USA and other countries in recent years, and in association with nonpolio enterovirus infection. This represents a significant challenge to clinicians and causes significant concern to the general public. Acute flaccid paralysis (AFP) is the long-known limb paralytic syndrome caused by a viral pathogen. AFM is a subset of AFP that is also characterized by a limb paralytic condition, but it has certain distinct features such as lesions in magnetic resonance imaging of the spinal cord gray matter. AFM leads to spinal cord, brainstem, or motor neuron dysfunction. The clinical phenotypes, pathology, and patient presentation of AFM closely mimic AFP. This article provides a concise overview of our current understanding of AFM and the clinical features that distinguish AFM from AFP and similar other neurological infectious and autoimmune diseases or disorders. We also discuss the diagnosis, clinical pathology, possible pathogenetic mechanisms, and currently available therapies.

Life-Threatening Infections Due to Live-Attenuated Vaccines: Early Manifestations of Inborn Errors of Immunity

Live-attenuated vaccines (LAVs) can protect humans against 12 viral and three bacterial diseases. By definition, any clinical infection caused by a LAV that is sufficiently severe to require medical intervention attests to an inherited or acquired immunodeficiency that must be diagnosed or identified. Self-healing infections can also result from milder forms of immunodeficiency. We review here the inherited forms of immunodeficiency underlying severe infections of LAVs. Inborn errors of immunity (IEIs) underlying bacille Calmette-Guérin (BCG), oral poliovirus (OPV), vaccine measles virus (vMeV), and oral rotavirus vaccine (ORV) disease have been described from 1951, 1963, 1966, and 2009 onward, respectively. For each of these four LAVs, the underlying IEIs show immunological homogeneity despite genetic heterogeneity. Specifically, BCG disease is due to inborn errors of IFN-γ immunity, OPV disease to inborn errors of B cell immunity, vMeV disease to inborn errors of IFN-α/β and IFN-λ immunity, and ORV disease to adaptive immunity. Severe reactions to the other 11 LAVs have been described yet remain "idiopathic," in the absence of known underlying inherited or acquired immunodeficiencies, and are warranted to be the focus of research efforts. The study of IEIs underlying life-threatening LAV infections is clinically important for the affected patients and their families, as well as immunologically, for the study of the molecular and cellular basis of host defense against both attenuated and parental pathogens.

Assessment of seroprevalence against poliovirus among Italian adolescents and adults

In 2002, the WHO European Region was declared polio-free. Nonetheless global eradication has not yet been completed and the reintroduction from at risk areas is still possible. This seroprevalence study evaluated samples collected from each Italian region in the 12−50 years old age range to assess protection against Poliovirus (PV) 1, 2 and 3 among subjects immunised with different vaccination schedules. 1073 samples (50.5% females) were examined. WHO standardized microneutralization assay was used. Seroprotection rates were 92.9%, 96.2% and 83.4%, for PV1, PV2 and PV3, respectively. Geometric Mean Titres (GMTs) were higher for PV2 (52.8) and PV1 (41.1) than for PV3 (21.0). Increasing the age, a decreasing trend in seropositivity was observed, in particular for PV3. The 2017–2019 Italian National Immunisation Plan emphasises, as primary objective, the maintenance of the polio-free status and strongly validates the 2 + 1 schedule in the first year of life with IPV vaccine associated with the administration of booster doses at 6 years and during the adolescence. Surveillance system and high population immunity are crucial to ensure the maintenance of polio-free status.

Poliovirus and Other Enteroviruses from Environmental Surveillance in Italy, 2009-2015

Within the initiatives for poliomyelitis eradication by WHO, Italy activated an environmental surveillance (ES) in 2005. ES complements clinical Acute Flaccid Paralysis (AFP) surveillance for possible polio cases, detects poliovirus circulation in environmental sewage, and is used to monitor transmission in communities. In addition to polioviruses, the analyses comprised: (i) the monitoring of the presence of non-polio enteroviruses in sewage samples and (ii) the temporal and geographical distribution of the detected viruses. From 2009 to 2015, 2880 sewage samples were collected from eight cities participating in the surveillance. Overall, 1479 samples resulted positive for enteroviruses. No wild-type polioviruses were found, although four Sabin-like polioviruses were detected. The low degree of mutation found in the genomes of these four isolates suggests that these viruses have had a limited circulation in the population. All non-polio enteroviruses belonged to species B and the most frequent serotype was CV-B5, followed by CV-B4, E-11, E-6, E-7, CV-B3, and CV-B2. Variations in the frequency of different serotypes were also observed in different seasons and/or Italian areas. Environmental surveillance in Italy, as part of the 'WHO global polio eradication program', is a powerful tool to augment the polio surveillance and to investigate the silent circulation or the re-emergence of enteroviruses in the population.

A simple and safe antibody neutralization assay based on polio pseudoviruses

The evaluation of the immunogenicity of Sabin strain based Inactivated Poliovirus Vaccines (sIPV) necessitates the use of wild strains in neutralization assays to assess the potential cross-reactivity of antibodies. The live virus strains including wild and Sabin strains must be handled in level 3 biocontainment laboratories. To develop an alternative assay without the use of a live virus, we constructed Mahoney, MEF-1, and Saukett pseudovirions by inserting luciferase reporter genes into intact capsid proteins. Afterward, we developed a pseudovirus-based neutralization test (pNT) and evaluated for the specificity and reproducibility. We tested serum samples from a clinical trial on sIPV vaccines by pNT and compared the results with those obtained from conventional neutralization tests (cNT). A strong correlation was observed between two methods, with the correlation coefficients of all three types of IPV vaccines being greater than 0.82 (p < 0.0001). The Geometric Mean Titer (GMT) values obtained by pNT were approximately four times higher than that by cNT, revealing the better sensitivity of pNT. In conclusion, pNT is a safe, rapid and sensitive quantitative assay with the potential of being an alternative for the evaluation of the potency of polio vaccines.

Immunogenicity of sequential inactivated and oral poliovirus vaccines (OPV) versus inactivated poliovirus vaccine (IPV) alone in healthy infants: A systematic review and meta-analysis

BACKGROUND

The emergence of vaccine-associated paralytic poliomyelitis has become an ongoing burden of poliomyelitis. During this special period from OPV to IPV-only immunization schedule, we did a meta-analysis to compare the immunogenicity of sequential IPV and OPV versus IPV alone in healthy infants.

METHODS

This systematic review and meta-analysis was registered at international prospective register of systematic reviews (PROSPERO), and the number was CRD42017054889. We performed it as described.

RESULTS

Finally, 6 articles were qualified for our review. The results showed that seroconversion rates against all 3 serotype polioviruses were non-inferior and Geometric mean antibody titers (GMTs) were superior in sequential schedules compared with IPV-only schedule. Thus, the sequential vaccination schedules could induce a stronger immunogenicity.

CONCLUSIONS

To decrease vaccine-associated and vaccine-derived poliomyelitis, it is a reasonable option to select sequential schedules during this special transition from OPV to IPV-only immunization schedule, which coincides with the current WHO recommendations.

Large-Scale Survey of Human Enteroviruses in Wastewater Treatment Plants of a Metropolitan Area of Southern Italy

Human enteroviruses (HEVs) occur in high concentrations in wastewater and can contaminate receiving environmental waters, constituting a major cause of acute waterborne disease worldwide. In this study, we investigated the relative abundance, occurrence, and seasonal distribution of polio and other enteroviruses at three wastewater treatment plants (WWTPs) in Naples, Southern Italy, from January 2010 to December 2014. Influent and effluent samples from the three WWTPs were collected monthly. One hundred and sixty-one of the 731 wastewater samples collected (22.0%) before and after water treatment were CPE positive on RD cells; while no samples were positive on L20B cells from any WWTPs. Among the 140 non-polio enterovirus isolated from inlet sewage, 69.3% were Coxsackieviruses type B and 30.7% were Echoviruses. Among these, CVB3 and CVB5 were most prevalent, followed by CVB4 and Echo6. The twenty-one samples tested after treatment contained 6 CVB4, 5 CVB3, 3 Echo11, and 2 Echo6; while other serotypes were isolated less frequently. Data on viral detection in treated effluents of WWTPs confirmed the potential environmental contamination by HEVs and could be useful to establish standards for policies on wastewater management.

Poliovirus Excretion in Children with Primary Immunodeficiency Disorders, India

Prolonged excretion of poliovirus can occur in immunodeficient patients who receive oral polio vaccine, which may lead to propagation of highly divergent vaccine-derived polioviruses (VDPVs), posing a concern for global polio eradication. This study aimed to estimate the proportion of primary immunodeficient children with enterovirus infection and to identify the long-term polio/nonpolio enterovirus excreters in a tertiary care unit in Mumbai, India. During September 2014–April 2017, 151 patients received diagnoses of primary immunodeficiency (PID). We isolated 8 enteroviruses (3 polioviruses and 5 nonpolio enteroviruses) in cell culture of 105 fecal samples collected from 42 patients. Only 1 patient with severe combined immunodeficiency was identified as a long-term VDPV3 excreter (for 2 years after identification of infection). Our results show that the risk of enterovirus excretion among children in India with PID is low; however, systematic screening is necessary to identify long-term poliovirus excreters until the use of oral polio vaccine is stopped.

New insights into physiopathology of immunodeficiency-associated vaccine-derived poliovirus infection; systematic review of over 5 decades of data

Widespread administration of oral poliovirus vaccine (OPV) has decreased global incidence of poliomyelitis by ≈99.9%. However, the emergence of vaccine-derived polioviruses (VDPVs) is threatening polio-eradication program. Primary immunodeficiency (PID) patients are at higher risks of vaccine-associated paralytic poliomyelitis (VAPP) and prolonged excretion of immunodeficiency-associated VDPV (iVDPV). We searched Embase, Medline, Science direct, Scopus, Web of Science, and CDC and WHO databases by 30 September 2016, for all reports of iVDPV cases. Patient-level data were extracted form eligible studies. Data on immunization coverage and income-level of countries were extracted from WHO/UNICEF and the WORLD BANK databases, respectively. We assessed bivariate associations between immunological, clinical, and virological parameters, and exploited multivariable modeling to identify independent determinants of poliovirus evolution and patients' outcomes. Study protocol was registered with PROSPERO (CRD42016052931). 4329 duplicate-removed titles were screened. A total of 107 iVDPV cases were identified from 68 eligible articles. The majority of cases were from higher income countries with high polio-immunization coverage. 74 (69.81%) patients developed VAPP. Combined immunodeficiency patients showed lower rates of VAPP (p < .001) and infection clearance (p = .02), compared to humoral immunodeficiency patients. The rate of poliovirus genomic evolution was higher at early stages of replication, decreasing over time until reaching a steady state. Independent of replication duration, higher extent (p = .04) and rates (p = .03) of genome divergence contributed to a less likelihood of virus clearance. PID type (p < .001), VAPP occurrence (p = .008), and income-level of country (p = .04) independently influenced patients' survival. With the use of OPV, new iVDPVs will emerge independent of the rate of immunization coverage. Inherent features of PIDs contribute to the clinical course of iVDPV infection and virus evolution. This finding could shed further light on poliomyelitis pathogenesis and iVDPV evolution pattern. It also has implications for public health, the polio eradication effort and the development of effective antiviral interventions.

Vaccine-associated paralytic poliomyelitis in a patient with acute lymphocytic leukemia

We report a case of vaccine-associated paralytic poliomyelitis (VAPP) in an immunocompromised patient with acute lymphocytic leukemia who was initially diagnosed with aseptic meningitis. Isolation of Sabin-like type 1 poliovirus from the patient's cerebrospinal fluid made this a case of vaccine-related poliovirus (VRPV) infection. The patient developed paralysis and respiratory distress and deceased a few months after onset of paralysis with respiratory failure. This tragic case report highlights the emergence of VAPP and indicates the importance of timely diagnosis of VRPV infections to improve clinical management of VRPV-infected patients and to prevent the devastating consequences of silent introduction of VRPVs in treatment wards and eventually in the society.