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Viral Immunology Mar 2018Measles remains an important cause of child morbidity and mortality worldwide despite the availability of a safe and efficacious vaccine. The current measles virus (MeV)... (Review)
Review
Measles remains an important cause of child morbidity and mortality worldwide despite the availability of a safe and efficacious vaccine. The current measles virus (MeV) vaccine was developed empirically by attenuation of wild-type (WT) MeV by in vitro passage in human and chicken cells and licensed in 1963. Additional passages led to further attenuation and the successful vaccine strains in widespread use today. Attenuation is associated with decreased replication in lymphoid tissue, but the molecular basis for this restriction has not been identified. The immune response is age dependent, inhibited by maternal antibody (Ab) and involves induction of both Ab and T cell responses that resemble the responses to WT MeV infection, but are lower in magnitude. Protective immunity is correlated with levels of neutralizing Ab, but the actual immunologic determinants of protection are not known. Because measles is highly transmissible, control requires high levels of population immunity. Delivery of the two doses of vaccine needed to achieve >90% immunity is accomplished by routine immunization of infants at 9-15 months of age followed by a second dose delivered before school entry or by periodic mass vaccination campaigns. Because delivery by injection creates hurdles to sustained high coverage, there are efforts to deliver MeV vaccine by inhalation. In addition, the safety record for the vaccine combined with advances in reverse genetics for negative strand viruses has expanded proposed uses for recombinant versions of measles vaccine as vectors for immunization against other infections and as oncolytic agents for a variety of tumors.
Topics: Animals; Antibodies, Neutralizing; Antibodies, Viral; Disease Transmission, Infectious; Drug Discovery; Humans; Immunization Schedule; Measles; Measles Vaccine; Measles virus; Serial Passage; Technology, Pharmaceutical; Vaccines, Attenuated
PubMed: 29256824
DOI: 10.1089/vim.2017.0143 -
Methods in Molecular Biology (Clifton,... 2021Vaccination was developed by Edward Jenner in 1796. Since then, vaccination and vaccine development research has been a hotspot of research in the scientific community....
Vaccination was developed by Edward Jenner in 1796. Since then, vaccination and vaccine development research has been a hotspot of research in the scientific community. Various ways of vaccine development are successfully employed in mass production of vaccines. One of the most successful ways to generate vaccines is the method of virulence attenuation in pathogens. The attenuated strains of viruses, bacteria, and parasites are used as vaccines which elicit robust immune response and confers protection against virulent pathogens. This chapter brings together the most common and efficient ways of generating live attenuated vaccine strains in viruses, bacteria, and parasites.
Topics: Animals; Bacterial Vaccines; Cell Line; Codon Usage; Female; Gamma Rays; Gene Silencing; Humans; Immunization; Immunogenicity, Vaccine; Influenza A virus; Mice; MicroRNAs; Models, Animal; Mutagenesis; Orthomyxoviridae Infections; Protozoan Vaccines; Radiation, Ionizing; Vaccines, Attenuated; Vaccinology; Virulence
PubMed: 32959252
DOI: 10.1007/978-1-0716-0795-4_17 -
Future Microbiology 2015Live attenuated oral polio vaccine (OPV) and inactivated polio vaccine (IPV) are the tools being used to achieve eradication of wild polio virus. Because OPV can rarely... (Review)
Review
Live attenuated oral polio vaccine (OPV) and inactivated polio vaccine (IPV) are the tools being used to achieve eradication of wild polio virus. Because OPV can rarely cause paralysis and generate revertant polio strains, IPV will have to replace OPV after eradication of wild polio virus is certified to sustain eradication of all polioviruses. However, uncertainties remain related to IPV's ability to induce intestinal immunity in populations where fecal-oral transmission is predominant. Although substantial effectiveness and safety data exist on the use and delivery of OPV and IPV, several new research initiatives are currently underway to fill specific knowledge gaps to inform future vaccination policies that would assure polio is eradicated and eradication is maintained.
Topics: History, 20th Century; History, 21st Century; Humans; Poliomyelitis; Poliovirus Vaccines; Vaccination; Vaccines, Attenuated; Vaccines, Inactivated
PubMed: 25824845
DOI: 10.2217/fmb.15.19 -
Human Vaccines & Immunotherapeutics 2019Dengue is the world's most prevalent and important arboviral disease. More than 50% of the world's population lives at daily risk of infection and it is estimated more... (Review)
Review
Dengue is the world's most prevalent and important arboviral disease. More than 50% of the world's population lives at daily risk of infection and it is estimated more than 95 million people a year seek medical care following infection. Severe disease can manifest as plasma leakage and potential for clinically significant hemorrhage, shock, and death. Treatment is supportive and there is currently no licensed anti-dengue virus prophylactic or therapeutic compound. A single dengue vaccine, Sanofi Pasteur's Dengvaxia®, has been licensed in 20 countries but uptake has been poor. A safety signal in dengue seronegative vaccine recipients stimulated an international re-look at the vaccine performance profile, new World Health Organization recommendations for use, and controversy in the Philippines involving the government, regulatory agencies, Sanofi Pasteur, clinicians responsible for testing and administering the vaccine, and the parents of vaccinated children. In this review, we provide an overview of Dengvaxia's® development and discuss what has been learned about product performance since its licensure.
Topics: Animals; Dengue; Dengue Vaccines; Dengue Virus; Humans; Immunogenicity, Vaccine; Licensure; Philippines; Vaccination; Vaccines, Attenuated; World Health Organization
PubMed: 31589551
DOI: 10.1080/21645515.2019.1658503 -
Bioanalysis Feb 2018Compared with biologics, vaccine potency assays represent a special challenge due to their unique compositions, multivalency, long life cycles and global distribution.... (Review)
Review
Compared with biologics, vaccine potency assays represent a special challenge due to their unique compositions, multivalency, long life cycles and global distribution. Historically, vaccines were released using in vivo potency assays requiring immunization of dozens of animals. Modern vaccines use a variety of newer analytical tools including biochemical, cell-based and immunochemical methods to measure potency. The choice of analytics largely depends on the mechanism of action and ability to ensure lot-to-lot consistency. Live vaccines often require cell-based assays to ensure infectivity, whereas recombinant vaccine potency can be reliably monitored with immunoassays. Several case studies are presented to demonstrate the relationship between mechanism of action and potency assay. A high-level decision tree is presented to assist with assay selection.
Topics: Animals; Biological Assay; Chlorocebus aethiops; Drug Evaluation, Preclinical; Enzyme-Linked Immunosorbent Assay; Hep G2 Cells; Humans; Immunogenicity, Vaccine; Mice; Vaccination; Vaccine Potency; Vaccines, Attenuated; Vaccines, Inactivated; Vaccines, Subunit; Vero Cells
PubMed: 29333863
DOI: 10.4155/bio-2017-0176 -
Expert Review of Vaccines Dec 2017Before vaccination, varicella zoster virus (VZV), which is endemic worldwide, led to almost universal infection. This neurotropic virus persists lifelong by establishing... (Review)
Review
Before vaccination, varicella zoster virus (VZV), which is endemic worldwide, led to almost universal infection. This neurotropic virus persists lifelong by establishing latency in sensory ganglia, where its reactivation is controlled by VZV-specific T-cell immunity. Lifetime risk of VZV reactivation (zoster) is around 30%. Vaccine development was galvanised by the economic and societal burden of VZV, including debilitating zoster complications that largely affect older individuals. Areas covered: We describe the story of development, licensing and implementation of live attenuated vaccines against varicella and zoster. We consider the complex backdrop of VZV virology, pathogenesis and immune responses in the absence of suitable animal models and examine the changing epidemiology of VZV disease. We review the vaccines' efficacy, safety, effectiveness and coverage using evidence from trials, observational studies from large routine health datasets and clinical post-marketing surveillance studies and outline newer developments in subunit and inactivated vaccines. Expert commentary: Safe and effective, varicella and zoster vaccines have already made major inroads into reducing the burden of VZV disease globally. As these live vaccines have the potential to reactivate and cause clinical disease, developing alternatives that do not establish latency is an attractive prospect but will require better understanding of latency mechanisms.
Topics: Chickenpox; Chickenpox Vaccine; Clinical Trials as Topic; Drug Approval; Drug Discovery; Herpes Zoster; Herpes Zoster Vaccine; Humans; Product Surveillance, Postmarketing; Treatment Outcome; Vaccines, Attenuated; Vaccines, Subunit
PubMed: 29047317
DOI: 10.1080/14760584.2017.1394843 -
Cell Host & Microbe May 2020The live-attenuated oral poliovirus vaccine (OPV or Sabin vaccine) replicates in gut-associated tissues, eliciting mucosa and systemic immunity. OPV protects from...
The live-attenuated oral poliovirus vaccine (OPV or Sabin vaccine) replicates in gut-associated tissues, eliciting mucosa and systemic immunity. OPV protects from disease and limits poliovirus spread. Accordingly, vaccination with OPV is the primary strategy used to end the circulation of all polioviruses. However, the ability of OPV to regain replication fitness and establish new epidemics represents a significant risk of polio re-emergence should immunization cease. Here, we report the development of a poliovirus type 2 vaccine strain (nOPV2) that is genetically more stable and less likely to regain virulence than the original Sabin2 strain. We introduced modifications within at the 5' untranslated region of the Sabin2 genome to stabilize attenuation determinants, 2C coding region to prevent recombination, and 3D polymerase to limit viral adaptability. Prior work established that nOPV2 is immunogenic in preclinical and clinical studies, and thus may enable complete poliovirus eradication.
Topics: Adult; Animals; Chlorocebus aethiops; Disease Models, Animal; Female; Genetic Engineering; HeLa Cells; Humans; Immunogenicity, Vaccine; Male; Mice; Poliomyelitis; Poliovirus; Poliovirus Vaccine, Oral; RNA, Viral; RNA-Dependent RNA Polymerase; Recombination, Genetic; Vaccination; Vaccines, Attenuated; Vero Cells; Virulence
PubMed: 32330425
DOI: 10.1016/j.chom.2020.04.003 -
Methods in Molecular Biology (Clifton,... 2016Poliomyelitis is caused by poliovirus, which is a positive strand non-enveloped virus that occurs in three distinct serotypes (1, 2, and 3). Infection is mainly by the...
Poliomyelitis is caused by poliovirus, which is a positive strand non-enveloped virus that occurs in three distinct serotypes (1, 2, and 3). Infection is mainly by the fecal-oral route and can be confined to the gut by antibodies induced either by vaccine, previous infection or maternally acquired. Vaccines include the live attenuated strains developed by Sabin and the inactivated vaccines developed by Salk; the live attenuated vaccine (Oral Polio Vaccine or OPV) has been the main tool in the Global Program of Polio eradication of the World Health Organisation. Wild type 2 virus has not caused a case since 1999 and type 3 since 2012 and eradication seems near. However most infections are entirely silent so that sophisticated environmental surveillance may be needed to ensure that the virus has been eradicated, and the live vaccine can sometimes revert to virulent circulating forms under conditions that are not wholly understood. Cessation of vaccination is therefore an increasingly important issue and inactivated polio vaccine (IPV) is playing a larger part in the end game.
Topics: Global Health; Humans; Poliomyelitis; Poliovirus; Poliovirus Vaccine, Inactivated; Poliovirus Vaccine, Oral; Vaccination; Vaccines, Attenuated
PubMed: 26983727
DOI: 10.1007/978-1-4939-3292-4_1 -
The New England Journal of Medicine Feb 2024
Topics: Humans; Dengue; Dengue Vaccines; Dengue Virus; Vaccines, Attenuated
PubMed: 38294979
DOI: 10.1056/NEJMe2314240 -
Human Vaccines & Immunotherapeutics 2015Measles was an inevitable infection during the human development with substantial degree of morbidity and mortality. The severity of measles virus (MV) infection was... (Review)
Review
Measles was an inevitable infection during the human development with substantial degree of morbidity and mortality. The severity of measles virus (MV) infection was largely contained by the development of a live attenuated vaccine that was introduced into the vaccination programs. However, all efforts to eradicate the disease failed and continued to annually result in significant deaths. The development of molecular biology techniques allowed the rescue of MV from cDNA that enabled important insights into a variety of aspects of the biology of the virus and its pathogenesis. Subsequently these technologies facilitated the development of novel vaccine candidates that induce immunity against measles and other pathogens. Based on the promising prospective, the use of MV as a recombinant vaccine and a therapeutic vector is addressed.
Topics: Drug Carriers; Genetic Vectors; Humans; Measles; Measles Vaccine; Measles virus; Oncolytic Virotherapy; Vaccines, Attenuated; Vaccines, Synthetic
PubMed: 25483511
DOI: 10.4161/hv.34298