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Science China. Life Sciences May 2020African swine fever (ASF) is a devastating infectious disease in swine that is severely threatening the global pig industry. An efficacious vaccine is urgently required....
African swine fever (ASF) is a devastating infectious disease in swine that is severely threatening the global pig industry. An efficacious vaccine is urgently required. Here, we used the Chinese ASFV HLJ/18 as a backbone and generated a series of gene-deleted viruses. The virulence, immunogenicity, safety, and protective efficacy evaluation in specific-pathogen-free pigs, commercial pigs, and pregnant sows indicated that one virus, namely HLJ/18-7GD, which has seven genes deleted, is fully attenuated in pigs, cannot convert to the virulent strain, and provides complete protection of pigs against lethal ASFV challenge. Our study shows that HLJ/-18-7GD is a safe and effective vaccine against ASFV, and as such is expected to play an important role in controlling the spread of ASFV.
Topics: African Swine Fever; African Swine Fever Virus; Animals; Gene Deletion; Genome, Viral; Humans; Recombinant Proteins; Sequence Analysis, DNA; Swine; Vaccines, Attenuated; Viral Proteins; Viral Vaccines; Virulence
PubMed: 32124180
DOI: 10.1007/s11427-020-1657-9 -
Current Topics in Microbiology and... 2020Vaccines are considered one of the most important advances in modern medicine and have greatly improved our quality of life by reducing or eliminating many serious... (Review)
Review
Vaccines are considered one of the most important advances in modern medicine and have greatly improved our quality of life by reducing or eliminating many serious infectious diseases. Successful vaccines have been developed against many of the most common human pathogens, and this success has not been dependent upon any one specific class of vaccine since subunit vaccines, non-replicating whole-virus or whole-bacteria vaccines, and attenuated live vaccines have all been effective for particular vaccine targets. After completing the initial immunization series, one common aspect of successful vaccines is that they induce long-term protective immunity. In contrast, several partially successful vaccines appear to induce protection that is relatively short-lived and it is likely that long-term protective immunity will be critical for making effective vaccines against our most challenging diseases such as AIDS and malaria.
Topics: Bacterial Vaccines; Humans; Quality of Life; Vaccines; Vaccines, Attenuated; Vaccines, Subunit; Vaccinology; Viral Vaccines
PubMed: 30046984
DOI: 10.1007/82_2018_102 -
Cold Spring Harbor Perspectives in... Sep 2021Live attenuated, cold-adapted influenza vaccines exhibit several desirable characteristics, including the induction of systemic, mucosal, and cell-mediated immunity... (Review)
Review
Live attenuated, cold-adapted influenza vaccines exhibit several desirable characteristics, including the induction of systemic, mucosal, and cell-mediated immunity resulting in breadth of protection, ease of administration, and yield. Seasonal live attenuated influenza vaccines (LAIVs) were developed in the United States and Russia and have been used in several countries. In the last decade, following the incorporation of the 2009 pandemic H1N1 strain, the performance of both LAIVs has been variable and the U.S.-backbone LAIV was less effective than the corresponding inactivated influenza vaccines. The cause appears to be reduced replicative fitness of some H1N1pdm09 viruses, indicating a need for careful selection of strains included in multivalent LAIV formulations. Assays are now being implemented to select optimal strains. An improved understanding of the determinants of replicative fitness of vaccine strains and of vaccine effectiveness of LAIVs is needed for public health systems to take full advantage of these valuable vaccines.
Topics: Humans; Influenza A Virus, H1N1 Subtype; Influenza Vaccines; Russia; United States; Vaccine Efficacy; Vaccines, Attenuated
PubMed: 32253347
DOI: 10.1101/cshperspect.a038653 -
Expert Opinion on Biological Therapy Mar 2022Rotavirus is the primary cause of severe acute gastroenteritis among children under the age of five globally, leading to 128,500 to 215,000 vaccine-preventable deaths... (Review)
Review
INTRODUCTION
Rotavirus is the primary cause of severe acute gastroenteritis among children under the age of five globally, leading to 128,500 to 215,000 vaccine-preventable deaths annually. There are six licensed oral, live-attenuated rotavirus vaccines: four vaccines pre-qualified for global use by WHO, and two country-specific vaccines. Expansion of rotavirus vaccines into national immunization programs worldwide has led to a 59% decrease in rotavirus hospitalizations and 36% decrease in diarrhea deaths due to rotavirus in vaccine-introducing countries.
AREAS COVERED
This review describes the current rotavirus vaccines in use, global coverage, vaccine efficacy from clinical trials, and vaccine effectiveness and impact from post-licensure evaluations. Vaccine safety, particularly as it relates to the risk of intussusception, is also summarized. Additionally, an overview of candidate vaccines in the pipeline is provided.
EXPERT OPINION
Considerable evidence over the past decade has demonstrated high effectiveness (80-90%) of rotavirus vaccines at preventing severe rotavirus disease in high-income countries, although the effectiveness has been lower (40-70%) in low-to-middle-income countries. Surveillance and research should continue to explore modifiable factors that influence vaccine effectiveness, strengthen data to better evaluate newer rotavirus vaccines, and aid in the development of future vaccines that can overcome the limitations of current vaccines.
Topics: Child; Diarrhea; Humans; Immunization Programs; Infant; Rotavirus; Rotavirus Infections; Rotavirus Vaccines; Vaccines, Attenuated
PubMed: 34482790
DOI: 10.1080/14712598.2021.1977279 -
Vaccine Feb 2020Cholera remains a major global public health problem that is primarily linked to insufficient access to safe water and proper sanitation. Oral Cholera Vaccine (OCV) has... (Review)
Review
Cholera remains a major global public health problem that is primarily linked to insufficient access to safe water and proper sanitation. Oral Cholera Vaccine (OCV) has been recommended as an additional public health tool along with WASH in cholera endemic countries and in areas at risk for outbreaks. The new generation OCV is safe and offers good protection in older children and adults while limited protection in younger children less than five years of age has been observed. The combination of direct vaccine protection and vaccine herd immunity effects makes OCV highly cost-effective and, therefore, attractive for use in developing countries. Additionally, in recent studies OCV was safe in pregnant women, supporting its use in pregnant women in cholera endemic countries. However, knowledge need to be developed for current vaccines for their prolonged duration of protection and vaccines need improvements for better immune response in younger children. A single dose vaccination regimen would be more cost-effective and easier to deliver. Recent approaches have focused on designing genetically attenuated cholera strains for use in single-dose cholera vaccines. The global demand for OCV has been boosted by the WHO recommendation to use OCV and is driven largely by epidemics and outbreaks and has been increasing due to the availability of cheaper easy-to-use vaccines, feasibility of mass OCV vaccination campaigns, demonstration of protection to underserved population in precarious situations, and vaccine costs being borne by Gavi (Vaccine Alliance). For rapid access in emergency and equitable distribution of OCV in cholera-endemic low-income countries, a global OCV stockpile was established in 2013 with support from the Global Alliance for Vaccines and Immunization. The three WHO-prequalified vaccines are Dukoral®, Shanchol™, Euvichol® (and Euvichol® Plus presentation), the latter two being included in the stockpile.
Topics: Administration, Oral; Adult; Child; Cholera; Cholera Vaccines; Disease Outbreaks; Female; Humans; Pregnancy; Vaccination; Vaccines, Attenuated
PubMed: 31879125
DOI: 10.1016/j.vaccine.2019.12.011 -
Journal of Virology Oct 2023Porcine epidemic diarrhea (PED) caused by PED virus (PEDV) remains a big threat to the swine industry worldwide. Vaccination with live attenuated vaccine is a promising...
Porcine epidemic diarrhea (PED) caused by PED virus (PEDV) remains a big threat to the swine industry worldwide. Vaccination with live attenuated vaccine is a promising method to prevent and control PED, because it can elicit a more protective immunity than the killed vaccine, subunit vaccine, and so on. In this study, we found two obvious deletions in the genome of a high passage of AH2012/12. We further confirmed the second deletion which contains seven amino acids at the carboxy-terminus of the S2 gene and the start codon of ORF3 can reduce its pathogenicity . Animal experiments indicated that the recombinant PEDV with deleted carboxy-terminus of S gene showed higher IgG, IgA, neutralization antibodies, and protection effects against virus challenge than the killed vaccine. These data reveal that the engineering of the carboxy-terminus of the S2 gene may be a promising method to develop live attenuated vaccine candidates of PEDV.
Topics: Animals; Coronavirus Infections; Diarrhea; Porcine epidemic diarrhea virus; Swine; Swine Diseases; Vaccines, Attenuated; Vaccines, Inactivated; Viral Vaccines; Virulence
PubMed: 37732788
DOI: 10.1128/jvi.01063-23 -
Viruses Mar 2020Members of the genus are enveloped, negative-strand RNA viruses that include a number of highly contagious pathogens important to humans and animals. They are known to...
Members of the genus are enveloped, negative-strand RNA viruses that include a number of highly contagious pathogens important to humans and animals. They are known to be transmitted via the respiratory route and cause febrile diseases that can be fatal. Despite the availability of attenuated vaccines against several members, these viruses remain responsible for significant morbidity and mortality in their natural hosts worldwide. The development of molecular biology techniques over the past decades has helped increase the understanding of morbillivirus pathogenesis and explore the possibility to engineer their genomes as viral vectors. This Special Issue of explores recent advances in recombinant morbilliviruses platforms, especially measles virus (MV) and canine distemper virus (CDV), for novel vaccine development and oncolytic virotherapy against cancers. Topics in this special issue include parameters involved during the viral vector production, strategies of viral vector engineering, and the underlying mechanisms of the therapeutic effects exhibited by these vectors.
Topics: Genetic Engineering; Genetic Vectors; Humans; Morbillivirus; Oncolytic Virotherapy; Oncolytic Viruses; Vaccines, Attenuated; Viral Vaccines
PubMed: 32245003
DOI: 10.3390/v12030341 -
Retrovirology Oct 2019Vaccination against retroviruses is a challenge because of their ability to stably integrate into the host genome, undergo long-term latency in a proportion of infected... (Review)
Review
Vaccination against retroviruses is a challenge because of their ability to stably integrate into the host genome, undergo long-term latency in a proportion of infected cells and thereby escape immune response. Since clearance of the virus is almost impossible once infection is established, the primary goal is to achieve sterilizing immunity. Besides efficacy, safety is the major issue since vaccination has been associated with increased infection or reversion to pathogenicity. In this review, we discuss the different issues that we faced during the development of an efficient vaccine against bovine leukemia virus (BLV). We summarize the historical failures of inactivated vaccines, the efficacy and safety of a live-attenuated vaccine and the economical constraints of further industrial development.
Topics: Animals; Antibodies, Viral; Cattle; Enzootic Bovine Leukosis; Leukemia Virus, Bovine; Vaccination; Vaccines, Attenuated; Viral Vaccines
PubMed: 31590667
DOI: 10.1186/s12977-019-0488-8 -
Viruses Oct 2023African swine fever (ASF) is one of the most lethal infectious diseases affecting domestic pigs and wild boars of all ages. Over a span of 100 years, ASF has continued... (Review)
Review
African swine fever (ASF) is one of the most lethal infectious diseases affecting domestic pigs and wild boars of all ages. Over a span of 100 years, ASF has continued to spread over continents and adversely affects the global pig industry. To date, no vaccine or treatment has been approved. The complex genome structure and diverse variants facilitate the immune evasion of the ASF virus (ASFV). Recently, advanced technologies have been used to design various potential vaccine candidates and effective diagnostic tools. This review updates vaccine platforms that are currently being used worldwide, with a focus on genetically modified live attenuated vaccines, including an understanding of their potential efficacy and limitations of safety and stability. Furthermore, advanced ASFV detection technologies are presented that discuss and incorporate the challenges that remain to be addressed for conventional detection methods. We also highlight a nano-bio-based system that enhances sensitivity and specificity. A combination of prophylactic vaccines and point-of-care diagnostics can help effectively control the spread of ASFV.
Topics: Swine; Animals; African Swine Fever; Viral Vaccines; African Swine Fever Virus; Sus scrofa; Vaccines, Attenuated
PubMed: 38005846
DOI: 10.3390/v15112169 -
Nature Jul 2023Vaccination with Sabin, a live attenuated oral polio vaccine (OPV), results in robust intestinal and humoral immunity and has been key to controlling poliomyelitis. As...
Vaccination with Sabin, a live attenuated oral polio vaccine (OPV), results in robust intestinal and humoral immunity and has been key to controlling poliomyelitis. As with any RNA virus, OPV evolves rapidly to lose attenuating determinants critical to the reacquisition of virulence resulting in vaccine-derived, virulent poliovirus variants. Circulation of these variants within underimmunized populations leads to further evolution of circulating, vaccine-derived poliovirus with higher transmission capacity, representing a significant risk of polio re-emergence. A new type 2 OPV (nOPV2), with promising clinical data on genetic stability and immunogenicity, recently received authorization from the World Health Organization for use in response to circulating, vaccine-derived poliovirus outbreaks. Here we report the development of two additional live attenuated vaccine candidates against type 1 and 3 polioviruses. The candidates were generated by replacing the capsid coding region of nOPV2 with that from Sabin 1 or 3. These chimeric viruses show growth phenotypes similar to nOPV2 and immunogenicity comparable to their parental Sabin strains, but are more attenuated. Our experiments in mice and deep sequencing analysis confirmed that the candidates remain attenuated and preserve all the documented nOPV2 characteristics concerning genetic stability following accelerated virus evolution. Importantly, these vaccine candidates are highly immunogenic in mice as monovalent and multivalent formulations and may contribute to poliovirus eradication.
Topics: Animals; Mice; Disease Models, Animal; Poliomyelitis; Poliovirus; Poliovirus Vaccine, Oral; Vaccines, Attenuated; Disease Eradication
PubMed: 37316671
DOI: 10.1038/s41586-023-06212-3