Fig 1 - available from: BMC Infectious Diseases
This content is subject to copyright. Terms and conditions apply.
The number of children from whom VDPVs were isolated by year of identification and the types of children (VDPV case, non-polio AFP case and healthy population) in China during 2001-2013. VDPV, vaccine-derived polioviruses; AFP, acute flaccid paralysis; healthy population, contacts of AFP cases or healthy subjects
Source publication
Background
The goal of polio eradication is to complete elimination and containment of all wild, vaccine-related and Sabin polioviruses. Vaccine-derived poliovirus (VDPV) surveillance in China from 2001–2013 is summarized in this report, which has important implications for the global polio eradication initiative.
Methods
Acute flaccid paralysis (...
Similar publications
Afghanistan is one of two countries where wild poliovirus (WPV) type 1 remains endemic. We conducted a facility-based cross-sectional survey of antipoliovirus antibodies in children in 14 provinces of Afghanistan. The provinces were selected based on programmatic priorities for polio eradication. Children aged 6–11 and 36–48 months attending outpat...
Introduction:
Chad is a country within the Lake Chad sub region, currently at risk for poliovirus infection. The Lake Chad Task Team on polio eradication in this sub region made significant efforts to reduce the risk of polio transmission in Chad by tacking immunization teams in the Island Settlement using a Geographic Information System (GIS) tec...
Enterovirus D68 (EV-D68) has emerged over the recent years, with large outbreaks worldwide. Increased occurrence has coincided with improved clinical awareness and surveillance of non-polio enteroviruses. Studies showing its neurotropic nature and the change in pathogenicity have established EV-D68 as a probable cause of Acute Flaccid Myelitis (AFM...
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 A...
Pakistan is one of the few countries where poliovirus transmission still persists, despite intensive efforts to eradicate the disease. Adequate vaccination coverage is essential to achieve polio eradication, but misconceptions about polio vaccines have hindered vaccination efforts. To address this issue, we conducted a mixed-methods study to explor...
Citations
... In this study, we reported an acute flaccid paralysis (AFP) case with four doses of inactive polio vaccine in Runan County, Zhumadian City, Henan Province, in February 2017. Although the patient was diagnosed with viral myositis by a provincial Polio Expert Committee after a 60-day follow-up physical examination, this case was diagnosed as VDPV patient due to the isolated type 3 VDPV, in accordance with the latest recommendations from the WHO [16]. This report described the results of epidemiological and laboratory investigations and the actions taken to prevent the circulation of VDPV. ...
Background
Vaccine-derived poliovirus (VDPV) is a potential threat to polio eradication because they can reintroduce into the general population and cause paralytic polio outbreaks, a phenomenon that has recently emerged as a prominent public health concern at the end of global polio eradication. This study aimed to describe the epidemiology and genetic characteristics of the first VDPV identified from a patient with acute flaccid paralysis (AFP), with four doses of inactivated polio vaccine immunization in Henan Province, China in 2017.
Methods
The patient was diagnosed with type 3 VDPV. Subsequently, a series of epidemiological approaches was implemented, including a retrospective search of AFP cases, rate of vaccination assessment, study of contacts, and supplementary immunization activities. Fecal samples were collected, viral isolation was performed, and the viral isolates were characterized using full-length genomic sequencing and bioinformatic analysis.
Results
Phylogenetic analysis showed that the viral isolates from the patient were different from other reported genetic clusters of type 3 VDPV worldwide. They were identified as a Sabin 3/Sabin 1 recombinant VDPV with a crossover site in the P2 region. Nucleotide substitutions, including U → C (472) and C → U (2493), have been identified, both of which are frequently observed as reversion mutations in neurovirulent type 3 poliovirus. A unique aspect of this case is that the patient had been vaccinated with four doses of inactive polio vaccine, and the serum neutralizing antibody for Sabin types 1 and 3 were 1∶16 and 1∶512, respectively. Thus, the patient was speculated to have been infected with type 3 VDPV, and the virus continued to replicate and be excreted for at least 41 d.
Conclusions
The existence of this kind of virus in human population is a serious risk and poses a severe challenge in maintaining a polio-free status in China. To the best of our knowledge, this is the first report of VDPV identified in the Henan province of China. Our results highlight the importance of maintaining a high-level vaccination rate and highly sensitive AFP case surveillance system in intercepting VDPV transmission.
... Oral poliovirus vaccine (OPV) has proven to be highly effective in the global effort to eradicate poliomyelitis because of its ability to induce both humoral and intestinal immunity, ease of administration, and low cost (1). Sabin-strain OPV contains live attenuated virus and induces immunity by replicating in the intestinal tract, triggering an immune response that clears the vaccine virus. ...
... However, among undervaccinated communities and persons with immunodeficiency, OPV mutations that arise during prolonged replication can result in the emergence of genetically divergent, neurovirulent vaccine-derived polioviruses (VDPVs). In addition, OPV has resulted in rare cases of vaccine-associated paralytic poliomyelitis (VAPP) among vaccine recipients or their close contacts (1). Identification of circulating polioviruses relies on surveillance of acute flaccid paralysis (AFP) and environmental surveillance of wastewater (i.e., sewage). ...
Oral poliovirus vaccine (OPV) has proven to be highly effective in the global effort to eradicate poliomyelitis because of its ability to induce both humoral and intestinal immunity, ease of administration, and low cost (1). Sabin-strain OPV contains live attenuated virus and induces immunity by replicating in the intestinal tract, triggering an immune response that clears the vaccine virus. However, among undervaccinated communities and persons with immunodeficiency, OPV mutations that arise during prolonged replication can result in the emergence of genetically divergent, neurovirulent vaccine-derived polioviruses (VDPVs). In addition, OPV has resulted in rare cases of vaccine-associated paralytic poliomyelitis (VAPP) among vaccine recipients or their close contacts (1). Identification of circulating polioviruses relies on surveillance of acute flaccid paralysis (AFP) and environmental surveillance of wastewater (i.e., sewage). In 2022, type 3 VDPV (VDPV3) was detected in stool specimens from an infant with primary immunodeficiency disorder (PID) through a pilot surveillance program to identify VDPVs in children with PIDs. Integrated AFP, environmental, and immunodeficiency-associated VDPV (iVDPV) surveillance is critical to detecting and containing all polioviruses and achieving the goal of global polio eradication.
... The switch from oral poliovirus vaccine (OPV) to inactivated poliovirus vaccine (IPV) was proposed as an important strategy for realizing the goal of eradicating poliomyelitis (4). However, although the implementation of this strategy has resulted in fewer cases caused by wild poliovirus strains, the existence of VDPVs still negatively impacts poliomyelitis eradication efforts (5,6). In this context, the World Health Organization (WHO) proposed a strategy of implementing a phased withdrawal of trivalent OPV (tOPV) and introducing IPV; this plan includes one or two doses of IPV to induce basic immunity against poliovirus, especially type II poliovirus, followed by one or two doses of bivalent OPV (bOPV) as a boost (2). ...
... The safety of the tOPV-tOPV-tOPV schedule has been demonstrated over its >50 years of use in Chinese children (12); the primary safety concern for this approach is the rare cases of VAPP (6,13). As part of new poliovirus eradication strategy, the final goal of which is to adopt an IPV-only immunization schedule and eradicate all wild polioviruses and VDPVs, a switch from tOPV to bOPV is necessary, and the safety of this change must be evaluated. ...
Background:
A comparative analysis of the immunogenicity and safety of different poliovirus immunization schedules in Chinese infants is imperative to guide the administration of efficient strategies for the eradication of poliomyelitis.
Methods:
A post hoc analysis was conducted with the data from two poliovirus vaccine clinical trials involving a combined total of 2,400 infants aged 60-90 days. Trivalent oral poliovirus vaccine (tOPV), bivalent oral poliovirus vaccine (bOPV), Sabin strain-based inactivated poliovirus vaccine (sIPV), and conventional inactivated poliovirus vaccine (cIPV) were used in different schedules, the immunogenicity and safety of which were compared 28 days after the last of three doses.
Results:
In a per-protocol set analysis, the tOPV-tOPV-tOPV schedule induced seroconversion in 99.1%, 98.2%, and 96.0% of the inoculated infants for poliovirus type I, II, and III, respectively. The seroconversions for poliovirus types I and III were each almost 100% after immunization with the cIPV-bOPV-bOPV, sIPV-sIPV-bOPV, cIPV-cIPV-bOPV, sIPV-sIPV-tOPV, cIPV-cIPV-tOPV, or sIPV-bOPV-bOPV schedule. However, the schedules that used one IPV dose followed by two (poliovirus type I and III) bOPV doses failed to induce high-level immunity against type II poliovirus. IPV-related schedules were associated with a slightly higher incidence of adverse events (AEs).
Conclusions:
If the capacity of IPV can be increased, two or more doses of IPV should be administered before vaccination with bOPV in a sequential schedule to improve immunity against type II poliovirus.
... The Global Polio Eradication Initiative (GPEI), which was launched in response to a directive from the World Health Assembly, has dramatically reduced the number of cases of wild poliovirus [which is an enterovirus (EV)] globally, including in China (1,2). The GPEI uses both the oral polio vaccine (which consists of live attenuated poliovirus strains) and the inactivated polio vaccine, both of which are very effective. ...
In July–December 2018, an outbreak of polio-like acute flaccid myelitis (AFM) occurred in Zhejiang province, China. Enterovirus (EV)-D68 infection has been reported to be associated with AFM. This study aimed to investigate the clinical presentation, laboratory findings, and outcomes of AFM patients. We investigated the clinical and virologic information regarding the AFM patients, and real-time PCR, sequencing, and phylogenetic analysis were used to investigate the cause of AFM. Eighteen cases met the definition of AFM, with a median age of 4.05 years (range, 0.9–9 years), and nine (50%) were EV-D68 positive. Symptoms included acute flaccid limb weakness and cranial nerve dysfunction. On magnetic resonance imaging, 11 (61.1%) patients had spinal gray matter abnormalities. Electromyography results of 16 out of 17 patients (94.1%) were abnormal. Cerebrospinal fluid (CSF) pleocytosis was common (94.4%), while CSF protein concentration was normal in all patients. There was little improvement after early aggressive therapy. Phylogenetic analysis revealed that EV-D68 subclade B3 was the predominant lineage circulating in Zhejiang province in 2018.
Objective
To actively monitor patients with primary immunodeficiency under the age of 18, understand the risk of adverse reactions after vaccination, and provide reference for developing vaccination evaluation measures for children with special health conditions.
Methods
A questionnaire survey was conducted on patients diagnosed with primary immunodeficiency who visited the Rheumatology and Immunology Department of Children’s Hospital of Chongqing Medical University from January 2022 to March 2023, collecting diagnosis and treatment information as well as the vaccination records of live vaccines; Collected two stool samples (with an interval of more than 24 hours) for virus detection, and analyzed the vaccine derived poliovirus.
Results
A total of 26 primary immunodeficiency patients were enrolled among 3312 monitored cases, including 5 cases of severe combined immunodeficiency, 7cases of primary antibody deficiency, and 14 cases of other types of immunodeficiency. Among the 21 cases with clear vaccination records, the vaccination rate of BCG and oral poliovirus vaccine were 95.24% and 71.43%, respectively. Among them, the vaccination rates of both vaccines for patients with severe combined immunodeficiency were 100% and 60.00%, respectively; and for patients with primary antibody deficiency were 100%. It was found that one patient with severe combined immunodeficiency had disseminated BCG infection after vaccination, and type Ⅲ immunodeficiency-associated vaccine-derived poliovirus was detected in his stool samples.
Conclusions
The proportion of primary immunodeficiency patients receiving live vaccines is high, and there is a risk of adverse reactions after vaccination, which brings a challenge to the goal of polio eradication. It is recommended to improve the awareness and ability of recognizing vaccination for children with immunodeficiency, promote the active monitoring of children with immunodeficiency in hospitals, and adjust the immunization strategy for polio vaccine in a timely manner.
An 8-month-old child diagnosed with severe combined immunodeficiency (SCID) was found to be excreting vaccine-derived poliovirus (VDPVs). Five stool samples from the child and stool samples from 24 contacts were collected during the following 7 months. Complete genome sequence by next generation sequencing (NGS) identified 0.7% to 1.4% nucleotide substitutions in the capsid P1 region of the first and the last isolates compared with Sabin 3 strain. Simplot analysis revealed that all isolates were Sabin 3/Sabin 1 recombinants, sharing a single recombination breakpoint in the 2C region. Multiple nucleotide variants were identified in the 5’UTR (T472→C and G395→A); amino acid mutations were identified in residues at VP1-6 (Thr to Ile), VP1-105 (Met to Thr), VP1-286 (Arg to Lys), VP2-155 (Lys to Glu), VP3-59 (Ser to Asn) and VP3-91 (Phe to Ser). These variants were commonly observed in other PV strains, which may contribute to attenuation and temperature sensitivity. None of the 24 tested contacts of the patient and related transmits was found to be infected with poliovirus. Our study provides a rapid and reliable method for the characterization of VDPV research in Poliovirus infection. In post-OPV era, immunodeficient people with persistent and chronic infection remain a major challenge for polio eradication in China.
In 2000, China was declared polio-free. However, in 2018, wild poliovirus (WPV) was still endemic in two of its neighboring countries, making WPV importation and outbreak alarming possibilities. This study documents the seroprevalence of poliovirus antibodies before and after the polio vaccine switch in 2012 and 2017 in Beijing. Cross-sectional population-based serologic surveys were conducted in 2012 and 2017 in Beijing. The study subjects were selected from 10 different age groups (<1, 1–4, 5–9, 10–14, 15–19, 20–24, 25–29, 30–34, 35–39, and ≥40 y) using a multi-stage-stratified sampling method. Neutralizing antibody titers against poliovirus serotypes 1 (P1), 2 (P2), and 3 (P3) were assayed by World Health Organization standards. The seropositive rates (SR) and geometric mean titer (GMT) of the neutralizing antibodies were 91.71% and 1:130.26, respectively, for P1, 94.09% and 1:113.39, respectively, for P2, and 88.78% and 1:79.65, respectively, for P3 before the switch in 2012, and 87.78% and 1:108.93, respectively, for P1, and 81.67% and 1:70.56, respectively, for P3 after the switch in 2017, with a statistically significant difference for P1 and P3 between 2012 and 2017. The neutralizing antibodies for all poliovirus serotypes differed among different age and vaccination groups in both 2012 and 2017. After switching polio vaccines twice in 2014 and 2016, the P1 and P3 polio antibody levels were lower in 2017 than in 2012. The P2 antibody levels were determined from the first dose of IPV. The seroprevalence of poliovirus antibodies after adjustment of the immunization schedule of the polio vaccine on January 1, 2020, must be further monitored.
