Safety Evaluation of a Potent Tetanus Vaccine (250 Lf) in Guinea Pigs (Cavia procellus)

A subacute toxicity study of a potent tetanus toxoid (250 Lf) was carried out in guinea pigs.The toxoid was injected subcutaneously at the nape of the neck at dose levels of 1.0, 1.5.and 2.0 ml in Groups Ⅱ. Ⅲ. and Ⅳ, respectively.In the controls (Group Ⅰ) 2.0 ml of aluminum phosphate suspension was given in each injection.Periodic evaluations of body weight, food/water intake, general observable behavior, hematology.and blood chemistry in toxoid-injected guinea pigs were similar to those in control guinea pigs.Thus, the toxoid did not cause any side effects up to four times the dose proposed for humans.1990 Academic Press, Inc.

Safety Observation Study on Haemophilus Influenza Type B Conjugate Vaccines Injected at Different Sites in Chinese Infants

In the present study, the safety of Hoemophilus influenza type b conjugate vaccines inoculated in the upper arm deltoid and vastus lateralis muscle was evaluated. 680 infants aged 2-5 months and 6-12 months were selected to be the research subjects in whom the Hib conjugate vaccines were inoculated by injection in the upper arm deltoid and vastus lateralis muscle, respectively. The safety analysis indicated that there were no statistic differences in the incidence rates of adverse reactions when the Hib conjugate vaccines were inoculated at different sites. So we concluded that the safety of inoculation injection of Hib conjugate vaccines in vastus lateralis muscle was the same as that inoculated in the upper arm deltoid.

Mucosal COVID-19 vaccines:Risks,benefits and control of the pandemic

Based on mucosal immunization to promote both mucosal and systemic immune responses,next-generation coronavirus disease 2019(COVID-19)vaccines would be administered intranasally or orally.The goal of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)vaccines is to provide adequate immune protection and avoid severe disease and death.Mucosal vaccine candidates for COVID-19 including vector vaccines,recombinant subunit vaccines and live attenuated vaccines are under development.Furthermore,subunit protein vaccines and virus-vectored vaccines have made substantial progress in preclinical and clinical settings,resulting in SARS-CoV-2 intranasal vaccines based on the previously successfully used nasal vaccines.Additional to their ability to trigger stable,protective immune responses at the sites of pathogenic infection,the development of‘specific’mucosal vaccines targeting coronavirus antigens could be an excellent option for preventing future pandemics.However,their efficacy and safety should be confirmed.

Safety,immunogenicity,and cross-species protection of a plasmid DNA encoding Plasmodium falciparum SERA5 polypeptide,microbial epitopes and chemokine genes in mice and olive baboons

Incorporation of biomolecular epitopes to malarial antigens should be explored in the development of straintranscending malarial vaccines.The present study sought to determine safety,immunogenicity and cross-species efficacy of Plasmodium falciparum serine repeat antigen 5 polypeptide co-expressed with epitopes of BacilleCalmette Guerin（BCG）,tetanus toxoid（TT） and a chemokine gene.Olive baboons and BALB/c mice were randomly assigned into vaccine and control groups.The vaccine group animals were primed and boosted twice with pIRES plasmids encoding the SERA5 ＋ BCG ＋ TT alone,or with either CCL5 or CCL20 and the control group with pIRES plasmid vector backbone.Mice and baboons were challenged with P.berghei ANKA and P.knowlesi H strain parasites,respectively.Safety was determined by observing for injection sites reactogenicities,hematology and clinical chemistry.Parasitaemia and survivorship profiles were used to determine cross-species efficacy,and T cell phenotypes,Th1-,Th2-type,T-regulatory immune responses and antibody responses were assessed to determine vaccine immunogenicity.The pSeBCGTT plasmid DNA vaccines were safe and induced Thl-,Th2-type,and Tregulatory responses vaccinated animals showed enhanced CD4~＋（P〈0.01）,CD 8~＋ T cells（P〈 0.001） activation and IgG anti-SE36 antibodies responses（P〈 0.001） at week 4 and 8 post vaccination compared to the control group.Vaccinated mice had a 31.45-68.69%cumulative parasite load reduction and 60%suppression in baboons（P〈0.05）and enhanced survivorship（P〈 0.001） with no clinical signs of malaria compared to the control group.The results showed that the vaccines were safe,immunogenic and conferred partial cross-species protection.

Immunogenicity and safety of a new inactivated hepatitis A vaccine in young adults: a comparative study

To evaluate the immunogenicity, safety, and dosage of a new inactivated hepatitis A vaccine administered to young adults Methods One hundred and four normal adult volunteers, seronegative for hepatitis A virus and hepatitis B surface antigen, were randomly assigned to one of three groups The high dose group received a primary dose of 1000 units of the new vaccine, the low dose group received a primary dose of 500 units of the same vaccine, and the Havrix group received a primary dose of 1440 enzyme linked immunosorbent assay units of Havrix, a licensed inactivated hepatitis A vaccine All groups received a booster dose of the same vaccine 6 months after the primary dose Local and systemic adverse reactions, seroconversion rates, and geometric mean titers of hepatitis A virus antibodies were measured in all three groups Results Local and systemic reaction types and rates were similar in all three groups after primary and booster doses, although local reactions were more frequent in the Havrix group following the primary dose No serious adverse reactions occurred One month after the primary dose, the seroconversion rate was 87 5% in the high dose group, 70 0% in the low dose group, and 50.0% in the Havrix group ( P =0.001, versus the high dose group) At month 6 (before administration of the booster dose), seroconversion rates were 96 9% in the high dose group, 65 0% in the low dose group ( P =0 0029), and 68 8% in the Havrix group ( P =0 007) All subjects in all groups seroconverted by one month after receipt of the booster dose Geometric mean titers were similar in all three groups at month 1, but were higher in the high dose group (264 mIU/ml) than those in the Havrix group (135 mIU/ml) at month 6 ( P =0 0013) One month after the booster dose, geometric mean titers in the high dose group (2747 mIU/ml) were higher than those in the low dose group (1657 mIU/ml) ( P =0 0223) or in the Havrix group (1316 mIU/ml) ( P =0 01) Conclusions This new inactivated hepatitis A vaccine is immunogenic and safe; two doses of either 500 or 1000 units can induce hepatitis A virus antibodies well above the protection level

The effect of COVID-19 vaccines on sperm parameters: a systematic review and meta-analysis

Published data were gathered for a meta-analysis to determine the difference in sperm parameters before and after administration of different types of coronavirus disease 2019(COVID-19)vaccines,because the reproductive toxicity of COVID-19 vaccines has not yet been evaluated in clinical trials and COVID-19 has been associated with decreases in sperm quality.The preferred procedures for systematic reviews and meta-analyses were followed in the conduct and reporting of this study.The average sperm parameters of all sperm donors’multiple sperm donations were compared before and after receiving various COVID-19 vaccinations.Semen volume,total sperm motility,total sperm count,morphological change,and sperm concentration were the primary outcome measures.We compiled and analyzed the results of six studies on total sperm motility,six studies on semen volume,six studies on sperm concentration,two studies on morphological change,and two studies on total sperm count.Parameter comparisons with patients who had and had not been vaccinated were only reported in one of the included studies.When different types of COVID-19 vaccine injections were compared,no discernible differences in parameters were observed.According to the available data,the parameters of semen are unaffected by inactivated or messenger RNA(mRNA)COVID-19 vaccinations.To support these findings,additional prospectively designed research is required.

COVID-19 in children:epidemic issues and candidate vaccines

A large-scale vaccination of coronavirus disease-19(COVID-19)in adults has been conducted for nearly a year,and there is a growing recognition that immunization for children is also essential.It has been months since emergency use of pediatric COVID-19 vaccine was approved,we reviewed the prevalence and transmission of COVID-19 in children.The prevalence of COVID-19 in children is reduced due to vaccination even in a Delta prevalent period,so an increase in the vaccination rate is needed in children.Although the precise role of children in the transmission requires more research to uncover,they likely played a significant role,according to the available literature.We also described four candidate COVID-19 vaccines for children on their safety and immunogenicity and the impact of severe acute respiratory syndrome coronavirus 2 variants on childhood vaccination.Safety issues on pediatric vaccines post-approval,like adverse events following immunization and adverse events of special interest require studies on long-term and effective regulatory mechanisms.