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Poliovirus
Published in Patricia G. Melloy, Viruses and Society, 2023
Poliomyelitis is caused by the poliovirus that enters the body through the GI tract, causing no symptoms in most people it infects. In a small number of people who contract the poliovirus, paralysis can occur. Research on poliovirus began in earnest in the early 20th century following small outbreaks in the United States and Europe, and then a major epidemic in the United States in 1916. Seasonal cases of polio increased until the mid-1950s. Public health officials had few answers in stopping the spread of the virus, and people lived in fear every summer up until the mid-20th century when Jonas Salk and his team developed a polio vaccine through the support of the National Foundation for Infantile Paralysis. Over a million U.S. schoolchildren participated in a large vaccine trial in 1954 using an inactivated or killed polio vaccine (IPV) developed by Salk and his team that successfully prevented polio. Implementation of this vaccine caused a rapid decline in the cases of polio in the United States. IPV was replaced with an oral polio vaccine (OPV) developed by Albert Sabin in the 1960s and was used in the United States until the year 2000 when the medical community once again recommended the use of IPV. Around the world, the OPV helped reduce the incidence of polio and is still used in the campaign to eradicate polio from the planet. Roughly 90% of the world’s people are now free from fear of polio.
The Viruses
Published in Julius P. Kreier, Infection, Resistance, and Immunity, 2022
In nature the virus spreads from person to person by ingestion of food and water contaminated with fecal material. The virus is stable in the environment and is not inactivated by the stomach acids. Poliovirus infection in man can be inapparent. This is the most common form of infection. Poliovirus infection can also cause acute mild illness, acute nonparalytic aseptic meningitis, or paralytic poliomyelitis. The paralytic disease results in permanent paralysis and occurs more often in older children. Between 1940 and 1950, improved infant health care practices in developed countries prevented infections of young children. Infection then occurred when the children were older, and there was therefore a greater incidence of paralytic disease.
Pathophysiology
Published in Ibrahim Natalwala, Ammar Natalwala, E Glucksman, MCQs in Neurology and Neurosurgery for Medical Students, 2022
Ibrahim Natalwala, Ammar Natalwala, E Glucksman
Poliovirus, which is transmitted by the faecal-oral route, causes poliomyelitis. It is most often seen in developing countries in young unimmunised children. The virus replicates in the oropharynx and small intestine before spreading through the bloodstream to the CNS. Once in the CNS, it destroys ventral horn neurones in the spinal cord, resulting in lower motor neurone signs. A prodromal syndrome of malaise, headache, fever and abdominal pain is commonly seen. Lumbar puncture results would reveal a viral cause with no change in CSF glucose. Poliomyelitis is usually diagnosed by recovery of the virus from a stool culture.8
Research progress on substitution of in vivo method(s) by in vitro method(s) for human vaccine potency assays
Published in Expert Review of Vaccines, 2023
Xuanxuan Zhang, Xing Wu, Qian He, Junzhi Wang, Qunying Mao, Zhenglun Liang, Miao Xu
IPV plays a crucial role in preventing poliovirus. During the initial after licensure, the in vivo assays of IPV were generally performed in the lot release process, namely, the post-immunization neutralizing antibody titers in sera of animals (e.g. Guinea pigs, chickens, and rats) were detected [57]. D antigen, the protective immunogen of IPV, can stimulate the production of protective neutralizing antibodies within the body. Therefore, a D antigen-based in vitro assays can be established and used to ensure consistency throughout production. Based on a well-established production process, in vitro assays can more sensitively detect the degradation of poliomyelitis antigens and are more suitable for evaluating the consistency of batch-manufactured products [58].
Health economic analysis of vaccine options for the polio eradication endgame: 2022-2036
Published in Expert Review of Vaccines, 2022
Kimberly M. Thompson, Dominika A. Kalkowska, Kamran Badizadegan
Successful eradication of the transmission of wild polioviruses (WPVs) represents a first step in achieving the global goal of ending all cases of poliomyelitis. WPV eradication requires achieving sufficiently high immunization coverage in all countries at the same time, such that any WPVs exported from the last reservoir cannot restart transmission in WPV-free areas. Once transmission dies out in the last endemic reservoir, the endgame shifts to preventing reintroduction from stored viruses as part of global containment. This level of coordination makes eradication inherently global because eradicable infectious diseases, like polioviruses, pose interdependent risks, such that the management of risks in one country affect risks and outcomes in other countries [1,2]. Efforts by countries and the Global Polio Eradication Initiative (GPEI) led to the global certification of eradication of indigenous transmission of WPV type 2 in 2015 [3] and type 3 in 2019 [4]. During 2017–2020 type 1 WPV (WPV1) transmission remained limited to Afghanistan and Pakistan [5], but in 2021–2022, WPV1 exported from Pakistan led to reported cases in Malawi and Mozambique as of August 2022 [5].
Current development of Zika virus vaccines with special emphasis on virus-like particle technology
Published in Expert Review of Vaccines, 2021
Velasco Cimica, Jose M Galarza, Sujatha Rashid, Timothy T. Stedman
Historically, vaccines consisted of live-attenuated virus, inactivated pathogens, or detoxified toxins (toxoids) [131]. These classic vaccines had tremendous success in protecting the human population against a variety of infectious illnesses. For example, the smallpox vaccine, a live attenuated vaccine, was leading to the complete eradication of this viral disease [132]. Other classical vaccines have dramatically reduced the number of serious infections caused by diseases such as polio [133,134], measles, diphtheria, whooping cough, tetanus, and yellow fever [135]. Of note, the eradication campaign of polio reached a historical milestone on 25 August 2020: the Africa Regional Commission for the Certification of Poliomyelitis Eradication declared that the WHO African region was free from transmission of all indigenous wild polioviruses [136]. However, certain live-attenuated viral vaccines have demonstrated a rare reversion to virulence resulting in vaccine-associated disease and the risk of transmission [137,138]. Consequently, live attenuated vaccines may pose a safety concern especially for patients: 1) who are immunocompromised such as HIV and cancer patients; 2) with weakened immune systems such as the elderly and infants and; 3) pregnant women. Methodologies utilized to create an inactivated pathogen for vaccine use may render important epitopes ineffective, inducing, therefore, the production of sub-neutralizing antibodies [122,139]. In rare situations, live-attenuated and inactivated viral vaccines may induce severe side effects in recipients including those without preexisting conditions [137].