Cases Of Paralytic Poliomyelitis Research Articles

The ghost of polio haunts us once again. The appeal of the scientific community is clear: “Vaccinate your kids today!”

IntroductionIn the summer of 2022, a vaccination campaign for the prevention of poliomyelitis was launched and “The CDC recommend that all children be vaccinated against polio, or poliomyelitis”. The scientific community is on the alert for new cases of polio, which is spreading. Although polio seemed to have been almost completely eradicated throughout the world, the disease has surprisingly reappeared in some Western countries. The risk of international spread of poliovirus remains a Public Health Emergency of International Concern (PHEIC). MethodThe authors reviewed recent polio cases in some western countries which have caused significant public health concern and they underline the meaning and weight of this issue emphasizing the importance of vaccination. DiscussionIn June 2022, the British authorities announced that they had detected traces of a form of polio derived from a vaccine strain in the wastewater of some London boroughs. Although no cases of disease were identified, the British government immediately announced that it was proceeding to reinstate polio vaccination for all children. A few weeks later, on July 18, 2022, the New Jersey Department of Health notified the CDCP of the detection of type-2 poliovirus in an unvaccinated young man in the New York metropolitan area. This case immediately triggered an appeal from the CDCP to get vaccinated and, above all, to vaccinate children.Low vaccination coverage means that the population is constantly at risk of further cases of paralytic poliomyelitis. ConclusionThe appeal to vaccinate children against polio is crucial, as prevention through vaccination is the only defense against the disease. We think that an efficient vaccination campaign can positively influence the process of eliminating the virus. At the same time, however, it demonstrates that simply lowering one's guard can quickly lead to a resurgence of polio cases. Hence, until polio is eradicated, we can be sure that contagion by the wild virus and the risk of vaccine-derived poliovirus will remain possible.

Surveillance of acute flaccidparalysis and poliomyelitison some territories of Russia and South Vietnam. Part 1. Polioviruses and paralysis

The epidemiological and etiological aspects of poliomyelitis and acute flaccid paralysis (AFP) in Russia and Vietnam were analysed and compared. The polio-free status is maintained on 14 territories of Russia and 29 provinces of South Vietnam. The quality of epidemiological and virological surveillance for acute flaccid paralysis is in accordance with the requirements of the national and international polio surveillance systems. All AFP cases were revealed, registered, reported and investigated in both countries. The percentage of poliovirus isolation from 2492 samples collected from patients with acute flaccid paralysis and contact persons in different years in Russia ranged from 1.30.89 to 9.80.79. In South Vietnam, 2143 samples from patients with acute flaccid paralysis were investigated. In Russia and Vietnam, we isolated vaccine polioviruses of all three types with predominance of type 3 polioviruses (63% and 50%, respectively) in both countries. From AFP patients in Russia and Vietnam, polioviruses were isolated in 4.9% and 1.0% studied samples, respectively. Some VDPV strains were revealed on the territories of Russia and South Vietnam. Here, we describe five cases of vaccine-associated paralytic poliomyelitis registered in Russia and two cases of AFP caused by VDPV type 2 reported in Vietnam. To prevent the risk of developing vaccine-associated paralytic poliomyelitis, it is indispensable to ensure high-quality surveillance for acute flaccid paralysis, maintain 95% polio vaccine pediatric coverage and strictly comply with sanitary legislation, including the National Vaccination Schedule when vaccinating children, to improve virological surveillance of polioviruses using classical and new virological and molecular methods and to continue research on poliomyelitis, including development of new safe and effective poliovirus vaccines able to induce both humoral and mucosal immunity. The systematic control of adequate polio vaccination is indispensable in order to prevent transmission of imported wild polioviruses into polio free countries as well as circulation of vaccine-derived polioviruses worldwide.

Cost-effectiveness of various immunization schedules with inactivated Sabin strain polio vaccine in Hangzhou, China.

BackgroundIt is necessary to select suitable inactivated poliovirus vaccine(IPV) and live, attenuated oral poliovirus vaccine (OPV) sequential immunization programs and configure the corresponding health resources. An economic evaluation was conducted on the sequential procedures of Sabin strain-based IPV (sIPV) and bivalent OPV (bOPV) with different doses to verify whether a cost-effectiveness target can be achieved. This study aimed to evaluate the cost-effectiveness of different sIPV immunization schedules, which would provide convincing evidence to further change the poliovirus vaccine (PV) immunization strategies in China.MethodsFive strategies were included in this analysis. Based on Strategy 0(S0), the incremental cost (IC), incremental effect (IE), and incremental cost-effectiveness ratio (ICER) of the four different strategies (S1/S2/S3/S4) were calculated based on the perspective of the society. Seven cost items were included in this study. Results of field investigations and expert consultations were used to calculate these costs.ResultsThe ICs of S1/S2/S3/S4 was Chinese Yuan (CNY) 30.77, 68.58, 103.82, and 219.82 million, respectively. The IE of vaccine-associated paralytic poliomyelitis (IEVAPP) cases of S1/S2/S3/S4 were 0.22, 0.22, 0.22, and 0.11, respectively, while the IE of disability-adjusted life-years (IEDALY) of S1/S2/S3/S4 were 8.98, 8.98, 8.98, and 4.49, respectively. The ICERVAPP of S1/S2/S3/S4 gradually increased to CNY 13.99, 31.17, 47.19, and 199.83 million/VAPP, respectively. The ICERDALY of S1/S2/S3/S4 also gradually increased to CNY 0.34, 0.76, 1.16, and 4.90 million/DALY, respectively.ConclusionICERVAPP and ICERDALY were substantially higher for S3 (four-sIPV) and S4 (replacement of self-funded sIPV based on one-sIPV-three-bOPV). Two-sIPV-two-bOPV had a cost-effectiveness advantage, whereas S2/S3/S4 had no cost-effectiveness advantage.

Polio returns to the USA: An epidemiological alert

On July 21, 2022, the USA witnessed the first case of poliomyelitis after 3 decades of its eradication. Poliomyelitis is a crippling disease that results from infection with any one of the three related poliovirus types (referred to as types P1, P2, and P3), members of the enterovirus (picornavirus) family. The New York State Department of Health confirmed that a case of paralytic poliomyelitis was reported from a 20-year-old Hungarian traveller residing in Rockland County. The detected viral sequence has been found to have vaccine-derived poliovirus type 2 (VDPV2) suggesting an origin from the live attenuated oral polio vaccine (OPV). Since immunisation remains the only preventable measure, this article explores suggestions from the Centers for Disease Control and Prevention on reliable Inactivated (killed) polio vaccination in high-risk patients along with early case detection and treatment. In light of the above-mentioned findings, this research further details future recommendations like cessation of the OPV, encouragement of inactivated polio vaccine (IPV) in vaccination schedules, sensitive epidemiological surveillance system and appropriate training for healthcare providers. The affected countries have been further advised to have effective outbreak response strategy plans in place so that they can respond and stay prepared for such outbreaks in the future.

Genetic Characterization of Novel Oral Polio Vaccine Type 2 Viruses During Initial Use Phase Under Emergency Use Listing - Worldwide, March-October 2021.

The emergence and international spread of neurovirulent circulating vaccine-derived polioviruses (cVDPVs) across multiple countries in Africa and Asia in recent years pose a major challenge to the goal of eradicating all forms of polioviruses. Approximately 90% of all cVDPV outbreaks are caused by the type 2 strain of the Sabin vaccine, an oral live, attenuated vaccine; cVDPV outbreaks typically occur in areas of persistently low immunization coverage (1). A novel type 2 oral poliovirus vaccine (nOPV2), produced by genetic modification of the type 2 Sabin vaccine virus genome (2), was developed and evaluated through phase I and phase II clinical trials during 2017-2019. nOPV2 was demonstrated to be safe and well-tolerated, have noninferior immunogenicity, and have superior genetic stability compared with Sabin monovalent type 2 (as measured by preservation of the primary attenuation site [domain V in the 5' noncoding region] and significantly lower neurovirulence of fecally shed vaccine virus in transgenic mice) (3-5). These findings indicate that nOPV2 could be an important tool in reducing the risk for generating vaccine-derived polioviruses (VDPVs) and the risk for vaccine-associated paralytic poliomyelitis cases. Based on the favorable preclinical and clinical data, and the public health emergency of international concern generated by ongoing endemic wild poliovirus transmission and cVDPV type 2 outbreaks, the World Health Organization authorized nOPV2 for use under the Emergency Use Listing (EUL) pathway in November 2020, allowing for its first use for outbreak response in March 2021 (6). As required by the EUL process, among other EUL obligations, an extensive plan was developed and deployed for obtaining and monitoring nOPV2 isolates detected during acute flaccid paralysis (AFP) surveillance, environmental surveillance, adverse events after immunization surveillance, and targeted surveillance for adverse events of special interest (i.e., prespecified events that have the potential to be causally associated with the vaccine product), during outbreak response, as well as through planned field studies. Under this monitoring framework, data generated from whole-genome sequencing of nOPV2 isolates, alongside other virologic data for isolates from AFP and environmental surveillance systems, are reviewed by the genetic characterization subgroup of an nOPV working group of the Global Polio Eradication Initiative. Global nOPV2 genomic surveillance during March-October 2021 confirmed genetic stability of the primary attenuating site. Sequence data generated through this unprecedented global effort confirm the genetic stability of nOPV2 relative to Sabin 2 and suggest that nOPV2 will be an important tool in the eradication of poliomyelitis. nOPV2 surveillance should continue for the duration of the EUL.

Untranslated region-5’ and viral protein 1-based genetic stability analysis of bulk polio in Indonesia 2010-2019

Cases of vaccine-associated paralytic poliomyelitis (VAPP) continued increasingly from 2010-2019 in the world. Oral polio vaccine (OPV) is the live attenuated virus-based vaccine that could genetically revert to neurovirulent during the vaccine production process or when the virus replicates in the human body. The poliovirus neurovirulence is determined by the UTR-5' region and VP1 coding region. UTR-5' played a role in protein translation and VP1 was responsible for the immunogenicity of the virus. Some reported mutations in UTR-5' and VP1 could affect the neurovirulence of poliovirus. In this study, we analyzed the genetic stability of the UTR-5' and VP1 in the bulk of OPV types -1 and -3 produced in 2010 - 2019. The results of the analysis of UTR-5' sequences in Sabin strain types-1 and -3 and VP1 sequences on Sabin virus type 1 did not show any mutations. Meanwhile, the VP1 sequences in Sabin strain type 3 showed nucleotide mutation C2493U that caused the substitution amino acid Thr6Ile amino acid in all samples of the type 3 bulk polio test. Based on the results of in silico analysis, this mutation in VP1 did not contribute significantly to the neurovirulence of the virus.

Enlightment of routine vaccination under the prevention and control of COVID-19 based on the circulating event of type Ⅲ vaccine-derived poliovirus in Shanghai

Since the Global Polio Eradication Initiative was launched by the World Health Assembly in 1988, significant progress has been made in global polio prevention and control. But the occurrence of vaccine-associated paralytic poliomyelitis cases and vaccine-derived poliovirus related cases have become a major challenge during the post-polio era. While coronavirus disease 2019(COVID-19) has brought serious disease burden and economic burden to all countries in the world, prevention and control of vaccine-preventable infectious diseases such as polio should not be neglected under the background of the global common fight against COVID-19. Taking the type Ⅲ VDPV cycle event in Shanghai as an example, the paper discussed how to do a good job of routine inoculation under the prevention and control of COVID-19 to strictly prevent the outbreak of vaccine-preventable infectious diseases.

Safety and Immunogenicity of Two Novel Type 2 Oral Poliovirus Vaccine Candidates Compared With Monovalent Type 2 Oral Poliovirus Vaccine in Children and Infants: Two Clinical Trials

There is an increasing incidence of paralytic poliomyelitis cases because of circulating vaccine-derived polioviruses over the past 3 years. The person-to-person transmission of circulating vaccine-derived polioviruses that are neurovirulent are primarily responsible for this emergence of these outbreaks; the World Health Organization has designated type 2 circulating vaccine-derived polioviruses as a Public Health Emergency of International Concern.Two novel oral poliovirus vaccines (OPVs), OPV2-c1 and OPV2-c2, were tested for safety and immunogenicity in infants and children. These 2 novel poliovirus vaccines had genetic modifications introduced to enhance the stability of the Sabin attenuations and reduce the risk of reversion to neurovirulence. A previous study in healthy adults was conducted.This study was a phase 2 study with low and high doses of 2 novel OPV2 candidates in Panama through a multicenter, partly masked randomized study. In the phase 2 study, children received 2 high doses of novel OPV2-c1 or novel OPV2-c2 28 days apart. Infants (at 18–22 weeks of age) received 1 low dose or high dose of novel OPV2-c1 or novel OPV2-c2; randomly selected subsets (n = 50) of each group received a second dose 28 days later. Parents monitored and reported adverse events postvaccination. Type 2 poliovirus neutralizing antibodies were measured at days 0, 7, 28, and 56, and stool viral shedding was assessed up to 28 days postvaccination. The primary objective was the safety in all participants and noninferiority of the novel OPV2 day 28 seroprotection versus monovalent OPV2 in infants.In the novel OPV2 study, 47 children received the OPV2-c1 vaccine, and 53 received the OPV2-c2 vaccine as their first dose. A total of 97 of 100 children received a second dose; 45 children obtained the OPV2-c1 vaccine, and 52 received the novel OPV2-c2 vaccine. A total of 574 infants received the first dose of the novel OPV2 vaccine. A total of 36% of children (17 of 47) after the OPV2-c1vaccine and 26% of children (14 of 53) after the OPV2-c2 vaccine reported adverse events, consisting of loss of appetite, crying, fever, and irritability. There were 9 serious adverse events after OPV2-c1 and 13 after OPV2-c2 noted postvaccination (mostly pneumonia or bronchiolitis; 1 death from severe pneumonia), but none were believed to be causally associated with the vaccine. Infants also experienced crying, irritability, fever, and vomiting. The authors reported no consistent pattern of laboratory abnormalities or changes in laboratory assessments in both infants and children. Evaluable seroconversion rates were 94% to 100% after 1 to 2 doses in the novel OPV2 groups. The low-dose and high dose OPV2-c1 and the high dose OPV2-c2 met noninferiority criterion. Almost all infants who received either high dose OPV2-c1 or OPV2-c2 had shedding of type 2 virus in stools at day 7.The novel OPV 2 candidates appeared to be safe and immunogenic in children and infants in Panama. These candidates may represent a mechanism to decrease transmission of circulating neurovirulent type 2 vaccine-derived polioviruses.In the study, the authors report both results with the novel OPV2 vaccine candidates and a baseline study with monovalent Sabin OPV2 before cessation of administration. Most doses were administered to infants who experienced mostly transient and mild adverse effects. Noninferiority criterion was met with the high dose and low-dose OPV2-c1 and high dose OPV2-c2 vaccines. These novel candidates potentially represent a mechanism for immunity against type 2 polioviruses and the OPV2-c1 vaccine was listed under the World Health Organization Emergency Use for use against type 2 circulating vaccine-derived poliovirus outbreaks. With further larger studies, researchers will shed further light on safety, tolerability, and immunogenicity.

Adverse events following immunization with bivalent oral poliovirus vaccine in Jiangsu, China.

The bivalent oral poliovirus vaccine (bOPV; Sabin types 1 and 3) replaced the trivalent OPV (Sabin types 1, 2 and 3) globally in April 2016. A routine schedule of 1 dose of inactivated poliovirus vaccine and 3 subsequent doses of bOPV was implemented in Jiangsu simultaneously. The schedule was changed to 2 inactivated poliovirus vaccines + 2 bOPV on 1 September 2019. Although OPV type 2 has been removed, challenges persist because of adverse events following immunization (AEFIs) with bOPV. Therefore, we analysed and evaluated the safety profile of bOPV administered in children based on passive postmarketing AEFI surveillance. We collected all bOPV-related AEFI reports in Jiangsu from the Chinese National AEFI Information System (CNAEFIS) between May 2016 and April 2020. We obtained the administered doses of bOPV from the Jiangsu Provincial Electronic Immunization Registries System. A descriptive analysis was performed. In total, 2084 bOPV-related AEFIs were retrieved from the CNAEFIS. The overall reporting rate was 24.16 per 100 000 doses. Most AEFIs were nonserious. The most frequently reported symptoms were fever, rash and gastrointestinal disorders. Only 1.34% of AEFIs were serious, which thrombocytopenic purpura accounted for the largest category. Seventeen serious adverse events, including 2 vaccine-associated paralytic poliomyelitis (VAPP) cases, were considered to be related to bOPV vaccination. The rate of VAPP was 0.2 per million doses. AEFI analysis showed that bOPV was well tolerated. The events most frequently reported were nonserious. However, bOPV can still cause VAPP. Attention should be given to risks related to bOPV.

Primary immunodeficiency masks: A clinical case of vaccine-associated paralytic poliomyelitis

Human inborn immune-related errors comprise a heterogeneous group of rare genetically determined diseases of the immune system caused by loss or gain of function mutations altering relevant protein functions. The 2019 International Union of Immunological Societies recently proposed the classification for such pathologies now comprising 406 distinct disorders with 430 different gene defects. Predominantly antibody deficiencies represent most common group of human inborn immune-related errors, which diagnostics poses uneasy challenge for general practitioner due to a broad range of their clinical manifestations, such as infection, allergy, autoimmunity and malignancy. In addition, patients with human immune-related inborn errors may develop a vaccine-associated disease after administering live vaccines in accordance with the Russia-wide National Vaccine Schedule. Most common among vaccine-associated diseases are vaccine-associated paralytic poliomyelitis, vaccine-associated encephalitis (1 case per 1 000 000 doses of measles, rubella, varicella vaccine), vaccine-associated meningitis (1 case per 250 000 – 500 000 doses of mumps vaccine) as well as adverse effects related to BCG immunization: local (infiltration, cold abscess – 8.6 case per 100,000 vaccinated patients) and disseminated complications (BCG lymphadenitis – 15.5 case per 100 000 vaccinated patients, BCG osteitis – 3.5 case per 100 000 vaccinated patients). Vaccine-associated paralytic poliomyelitis in vaccinated patients occurs after the first, second and rarely third oral polio vaccine dose inoculation. Incidence rate for vaccineassociated paralytic polio after 1 and 3 oral vaccine inoculation ranges from 1 case per 700 000 vaccine doses to 1 case per 3 500 000, respectively. Vaccine-associated paralytic poliomyelitis mainly emerges due to inborn mutations related to humoral immunity after primary vaccination with oral polio vaccine or close contact of unvaccinated patients with subjects vaccinated with oral polio vaccine. Here, we describe a clinical case of vaccine-associated paralytic poliomyelitis in patient with primary immunodeficiency. Our is aimed at emphasizing importance of immunological alertness with regard to detecting primary immunodeficiencies and timely apply a replacement therapy prior to verifying type of immunodeficiency.

Vaccineassociated paralytic poliomyelitis and acute flaccid paralysis on some territories of Russia during 20 years

Aim: Analysis of the morbidity of vaccine-associated paralytic poliomyelitis and acute flaccid paralysis and the results of virological investigation of the patients on 14 territories of the Russian Federation in 1998-2017. Materials and methods: We investigated nearly 3000 stool samples from paralytic patients and contact persons. Isolation and identification of polioviruses were performed according to WHO recommendations with the help of cell lines RD and L20B. We conducted the sequencing of the genome fragments VP3-VP1, VP1-2A and full sequencing of genome region VP1 of 45 poliovirus strains. Results: From 1998 till 2017 1257 cases of acute flaccid paralysis were registered on 14 territories of Russia, 15 cases of which (1,2%) were classified as vaccine-associated paralytic poliomyelitis. From these patients 9 children were non vaccinated and 6 children received from one to four doses of oral poliomyelitis vaccine. The percentage of the detection of polioviruses from the patients and contact persons in different years was not equal and constituted from 3, 4±0,89% to 9, 5±0,79%. All in all from the patients with acute flaccid paralysis and contact persons we isolated 191 polioviruses, 60 of them belonged to type 1, 55 polioviruses were identified as types 2 and 76 as type 3. Some cases of vaccine-associated paralytic poliomyelitis are described in the article; polioviruses were isolated from all these patients. The sequencing of the genome fragments of 45 poliovirus strains showed that the majority of them had the nucleotide substitutions including neurovirulent substitutions. Conclusion:In order to prevent the risk of the appearance of vaccine-associated paralytic poliomyelitis it is necessary to maintain the high quality of surveillance of poliomyelitis and acute flaccid paralysis, to ensure the 95% coverage of children with poliomyelitis vaccine, to minimize the cases of groundless delays of vaccination according to medical recommendations and parents’ refusals to vaccinate children against poliomyelitis and to respect strictly the National calendar of vaccination.

Environmental Surveillance of Polioviruses in Armenia, Colombia before Trivalent Oral Polio Vaccine Cessation.

Although acute flaccid paralysis (AFP) surveillance is the “gold standard” for detecting cases of polio, environmental surveillance can provide supplementary information in the absence of paralytic poliomyelitis cases. This study aimed to detect the introduction and/or circulation of wild poliovirus or vaccine-derived polioviruses (VDPV) in wastewater, covering a significant population of Armenia, Colombia, before trivalent oral polio vaccine (OPV) cessation. Between March and September 2015, 24 wastewater samples were collected from eight study sites in eight communes of Armenia, Colombia. Virus detection and characterization were performed using both cell culture (i.e., RD or L20B cells) and RT-PCR. Polioviruses were isolated in 11 (45.8%) of 24 wastewater samples. All isolates were identified as Sabin strains (type 1 = 9, type 3 = 2) by intratypic differentiation. Type 2 poliovirus was not detected in any of the samples. No wild poliovirus or VDPV was detected among the isolates. Non-polio enterovirus was identified in 8.3% (2/24) of the samples. This study revealed the excretion of Sabin poliovirus from OPV-immunized individuals, as well as the absence of VDPV and wild poliovirus in wastewaters of Armenia, Colombia. This confirms that environmental surveillance is an effective method, as an additional support to AFP surveillance, to monitor poliovirus during the OPV-to-IPV (inactivated polio vaccine) transition period.

Vaccine-associated paralytic poliomyelitis in the Russian Federation in 1998–2014

ObjectivesDifferent polio vaccination schemes have been used in Russia: oral polio vaccine (OPV) was used in 1998–2007 and inactivated polio vaccine (IPV) followed by OPV in 2008–2014. This article presents the characteristics of vaccine-associated paralytic poliomyelitis (VAPP) cases in Russia during this period. MethodsVAPP cases were identified through the acute flaccid paralysis surveillance system, classified by the National Expert Classification Committee. Criteria for a ‘recipient VAPP’ (rVAPP) case were poliomyelitis symptoms 6–30days after OPV administration, isolation of the vaccine virus, and residual paralysis 60days after disease onset. Unvaccinated cases with a similar picture 6–60days after contact with an OPV recipient were classified as ‘contact VAPP’ (cVAPP) cases. ResultsDuring 1998–2014, 127 VAPP cases were registered: 82 rVAPP and 45 cVAPP. During the period in which only OPV was used, rVAPP cases prevailed (73.8%); cases of rVAPP were reduced during the sequential scheme period (15%). Poliovirus type 3 (39.5%) and type 2 (23.7%) were isolated more often. Vaccine-derived poliovirus types 1, 2, and 3 were isolated from three cases of cVAPP. The incidence of VAPP cases was higher during the period of OPV use (1 case/1.59 million OPV doses) than during the sequential scheme period (1 case/4.18 million doses). ConclusionThe risk of VAPP exists if OPV remains in the vaccination schedule.

Cuba's Scientific Contributions to Global Polio Eradication.

Cuba eliminated polio in 1962 and was among the first countries to do so. Since then, only 20 cases of vaccine-derived paralytic poliomyelitis have been reported. Because Cuba used oral poliovirus vaccine exclusively in two mass campaigns usually in February and April each year, Sabin viruses were detected only within approximately 6-8 weeks after each annual campaign. This made Cuba a very attractive site to study the epidemiology of poliomyelitis in a tropical country without risk of secondary transmission of Sabin viruses for a large part of each year, an advantage over countries that used oral poliovirus vaccine continuously throughout the year in routine immunization programs. This report summarizes the unique scientific collaboration between Cuba's Ministry of Public Health and WHO, with participation by US scientists, in the global effort to eradicate polio. KEYWORDS Poliomyelitis, disease eradication, disease elimination, oral poliovirus vaccine, Sabin vaccine, inactivated poliovirus vaccine, Salk vaccine, Cuba, WHO.

Acute flaccid paralysis laboratorial surveillance in a polio-free country: Brazil, 2005–2014

ABSTRACTThe last case of paralytic poliomyelitis caused by wild poliovirus in Brazil occurred in 1989. The interruption of the indigenous poliovirus transmission was obtained through mass immunization campaigns to eligible children and an active epidemiological and laboratorial surveillance of all cases of acute flaccid paralysis (AFP) among children under 15 y of age. This paper describes and evaluates the performance of the AFP surveillance system in different geographic areas of Brazil between 2005 and 2014, using indicators recommended by WHO. AFP surveillance indicators as well as virological investigation of polio and non-polio enteroviruses in stool samples received in the laboratory were assessed from 2005–2014. During the period, 5463 cases of AFP were investigated. Of these, 55% were males and 45% were females. Those under 5 y of age represented 48% of all cases reported and investigated. AFP notification rate was within the acceptable values with mean value of 1.3 (North), 1.4 (Northeast), 1.1 (Southern), 1.0 (Southeast) and 1.4 (Midwest) cases of AFP per 100.000 population aged 15 y as well as the adequacy of fecal specimens received in the laboratory. Sabin- related polioviruses accounted for 1.7% of the isolates while, 6.7% were non-polio enterovirus with the values ranging from 5.0% to 8.9 %. No wild-type polio was found. The AFP epidemiological and laboratorial surveillance activities have been kept at appropriate levels in Brazil. These data are a very strong indication, which supports the status of country free of polio.

Vaccine-associated paralytic poliomyelitis in Russian Federation during the period of changes in vaccination schedule (2006-2013 y.y.)

The results of virologic testing of clinical materials and epidemiological analysis of vaccine-associated paralytic poliomyelitis (VAPP) cases obtained in 2006-2013 during AFP surveillance are presented. Among the 2976 cases of AFP 30 cases were vapp. 15 cases were observed in OPV recipients, whereas 15 cases were observed in non-vaccinated contacts. The age of the patients varied from 4 months to 5.5 years (13.6 ± 12.4 months old). Children younger than 1 year constituted 63.3% of the group; boys were dominant (73.3%); 53.3% of children were vaccinated with OPV; the time period between receipt of OPV and onset of palsy was from 2 to 32 days (18.7 ± 8.2). Lower paraparesis was documented in 48.3% of patients; lower monoparesis, in 37.9%; upper monoparesis, in 6.9%; tetraparesis with bulbar syndrome, in 6%. the majority of the patients (85.7%) had an unfavorable premorbid status. The violations of the humoral immunity were found in 73.9% cases: CVID (52.9%), hypogammaglobulinemia (41.2%), selective IgA deficiency (5.9%). In 70.6% cases damage to humoral immunity was combined with poor premorbid status. The most frequently observed (76%, p 0.05) represented the single type of poliovirus – type 2 (44%) and type 3 (32%). All strains were of the vaccine origin, the divergence from the homotypic Sabin strains fell within the region of the gene encoding VP1 protein, which did not exceed 0.5% of nucleotide substitutions except vaccine derived poliovirus type 2 – multiple recombinant (type 2 / type 3 / type 2 / type 1) with the degree of the divergence of 1.44% isolated from 6-month old unvaccinated child (RUS-08063034001). The frequency of the VAPP cases was a total of 1 case per 3.4 million doses of distributed OPV in 2006-2013; 2.2 cases per 1 million of newborns were observed. This frequency decreased after the introduction of the sequential scheme of vaccination (ipv, Opv) in 2008-2013 as compared with the period of exclusive use of OPV in 2006-2007: 1 case per 4.9 million doses, 1.4 cases per 1 million newborns and 1 case per 1.9 million doses, 4.9 cases per 1 million newborns, respectively.

Integrative representations and analyses of vaccine-induced intended protective immunity and unintended adverse events using ontology-based and theory-guided approaches.

While effective preventive vaccines induce intended protective immunity, they also induce unintended adverse events (AEs). Generally speaking, compared to killed, inactivated vaccines and protein vaccines, live attenuated vaccines induce more protective immune responses. However, live attenuated vaccines are also associated with more AEs and even more serious AEs. For example, while live attenuated smallpox vaccines were critical to the eradication of smallpox, approximately 20–30% of smallpox vaccine recipients also experienced with various AEs that range in prevalence and severity [1]. Inter-individual variations in cytokine and AE response after smallpox vaccinations are in part due to genetic variation. For another example, the attenuated oral poliovirus vaccine (OPV) efficiently induces intestinal immunity and durable humoral immunity. However, OPV has the disadvantage of genetic instability, contributing to rare and sporadic cases of vaccine-associated paralytic poliomyelitis and the emergence of genetically divergent vaccine-derived polioviruses [2]. These AEs are worsened in patients with primary immunodeficiencies. These results suggest that the intended protective immune responses and unintended adverse events are correlated and deserve being studied simultaneously.

Health and economic consequences of different options for timing the coordinated global cessation of the three oral poliovirus vaccine serotypes.

BackgroundWorld leaders remain committed to globally-coordinated oral poliovirus vaccine (OPV) cessation following successful eradication of wild polioviruses, but the best timing and strategy for implementation depend on existing and emerging conditions.MethodsUsing an existing integrated global poliovirus risk management model, we explore alternatives to the current timing plan of coordinated cessation of each OPV serotype (i.e., OPV1, OPV2, and OPV3 cessation for serotypes 1, 2, and 3, respectively). We assume the current timing plan involves OPV2 cessation in 2016 followed by OPV1 and OPV3 cessation in 2019 and we compare this to alternative timing options, including cessation of all three serotypes in 2018 or 2019, and cessation of both OPV2 and OPV3 in 2017 followed by OPV1 in 2019.ResultsIf Supplemtal Immunization Activity frequency remains sufficiently high through cessation of the last OPV serotype, then all OPV cessation timing options prevent circulating vaccine-derived poliovirus (cVDPV) outbreaks after OPV cessation of any serotype. The various OPV cessation timing options result in relatively modest differences in expected vaccine-associated paralytic poliomyelitis cases and expected total of approximately 10–13 billion polio vaccine doses used. However, the expected amounts of vaccine of different OPV formulations needed changes dramatically with each OPV cessation timing option. Overall health economic impacts remain limited for timing options that only change the OPV formulation but preserve the currently planned year for cessation of the last OPV serotype and the global introduction of inactivated poliovirus vaccine (IPV) introduction. Earlier cessation of the last OPV serotype or later global IPV introduction yield approximately $1 billion in incremental net benefits due to saved vaccination costs, although the logistics of implementation of OPV cessation remain uncertain and challenging.ConclusionsAll countries should maintain the highest possible levels of population immunity to transmission for each poliovirus serotype prior to the coordinated cessation of the OPV serotype to manage cVDPV risks. If OPV2 cessation gets delayed, then global health leaders should consider other OPV cessation timing options.

Vaccine associated paralytic poliomyelitis cases from children presenting with acute flaccid paralysis in Uganda.

A retrospective study to identify VAPP cases from the entire Uganda was conducted between January 2003 and December 2011. Eleven of the 106 AFP cases were VAPPs. The VAPP rate ranged from 0 to 3.39 cases per 1,000,000 birth cohorts and the peak was in 2009 when there was scaling up of OPV immunization activities following an importation of wild poliovirus in the country. All the subsequent polio suspect cases since then have been vaccine-associated polio cases. Our data support the strategy to withdraw OPV and introduce IPV progressively in order to mitigate against the paralysis arising from Sabin polioviruses.

Recuperación de virus de poliomielitis de una epidemia en Iquitos y de casos en el hospital del niño de Lima

Se ha aislado poliovirus de casos de poliomielitis paralítica de la epidemia de Iquitos. De siete muestras de heces, se aisló un poliovirus de tipo I, dos de tipo II y dos del tipo III. También se aisló un virus del tipo III de un contacto asintomático. Se presume que la fuente de infección pudo provenir de un servicio de agua recientemente contaminado con materias fecales; ésta puede ser la causa de la aparición de los tres tipos de virus en una sola epidemia. Se airló asimismo poliovirus de pacientes de poliomielitis paralitica del Hospital del Niño de Lima. En esos casos se recuperó un virus del tipo III y cuatro del tipo I.