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.

Determination of ribose and phosphorus contents in Haemophilus influenzae type b capsular polysaccharide by a quantitative NMR method using a single internal standard

The ribose and phosphorus contents in Haemophilus influenzae type b(Hib)capsular polysaccharide(CPS)are two important chemical indexes for the development and quality control of Hib conjugate vaccine.A quantitative ^(1)H-and ^(31)P-NMR method using a single internal standard was developed for simultaneous determination of ribose and phosphorus contents in Hib CPS.Hexamethylphosphoramide(HMPA)was successfully utilized as an internal standard in quantitative ^(1)H-NMR method for ribose content determination.The ribose and phosphorus contents were found to be affected by the concentration of polysaccharide solution.Thus,15–20 mg·L^(−1) was the optimal concentration range of Hib CPS in D_(2)O solution for determination of ribose and phosphorus contents by this method.The ribose and phosphorus contents obtained by the quantitative NMR were consistent with those obtained by traditional chemical methods.In conclusion,this quantitative ^(1)H-and ^(31)P-NMR method using a single internal standard shows good specificity,accuracy and precision,providing a valuable approach for the quality control of Hib glycoconjugate vaccines.

Prevalence and factors associated with pentavalent vaccination:a cross-sectional study in Southern China

Background Immunization is one of the most far-reaching and cost-effective strategies for promoting good health and saving lives.A complex immunization schedule,however,may be burdensome to parents and lead to reduced vaccine compliance and completion.Thus,it is critical to develop combination vaccines to reduce the number of injections and simplify the immunization schedule.This study aimed to investigate the current status of the pentavalent diphtheria-tetanus-acellular pertussis inactivated poliomyelitis andHaemophilus influenzae type B conjugate(DTaP-IPV/Hib)vaccination in Southern China as well as explore the factors in the general population associated with uptake and the differences between urban and rural populations.Methods A cross-sectional study was conducted with recently enrolled kindergarten students in Hainan Province between December 2022 and January 2023.The study employed a stratified multistage cluster random sampling method.Information regarding the demographic characteristics and factors that influence decisions were collected from the caregivers of children via an online questionnaire.Multivariate logistic regression was used to determine the factors associated with the status of DTap-IPV/Hib vaccinations.Results Of the 4818 valid responses,95.3%of children were aged 3-4 years,and 2856(59.3%)held ruralhukou.Coverage rates of the DTaP-IPV/Hib vaccine,from 1 to 4 doses,were 24.4%,20.7%,18.5%,and 16.0%,respectively.Caregivers who are concerned about vaccine efficacy[adjusted odds ratio(aOR)=1.53,95%confidence interval(CI):1.30-1.79],the manufacturer(aOR=2.05,95%CI:1.69-2.49),and a simple immunization schedule(aOR=1.26,95%CI:1.04-1.54)are factors associated with a higher likelihood of vaccinating children against DTaP-IPV/Hib.In addition,caregivers in urban areas showed more concern about the vaccine price(P=0.010)and immunization schedule(P=0.022)in regard to vaccinating children.Conclusions The DTaP-IPV/Hib vaccine coverage rate in Hainan Province remains low.Factors such as lower socioeconomic status,cultural beliefs,concerns about vaccine safety,and cost may hinder caregivers from vaccinating their children.Further measures,such as health education campaigns to raise knowledge and awareness,and encouragement of domestic vaccine innovation,which would reduce out-of-pocket costs,could be implemented to improve the coverage of DTap-IPV/Hib vaccination.

Polysaccharide conjugate vaccine:A kind of vaccine with great development potential

Diseases caused by microbial bacteria such as Haemophilus influenzae type b(Hib),Streptococcus pneumoniae and Neisseria meningitidis are still very serious disease,which has brought a lot of burden to many countries.Development of vaccine has brought hope for the prevention of such diseases.Polysaccharide conjugate vaccines have been shown to have very good effects in preventing such diseases.The polysaccharide co njugate vaccine adds the positive characteristics of protein antigens to the polysaccharide antigen,thereby improving the immunogenicity of the polysaccharide antigen,solving the problem that the polysaccharide vaccine cannot be effectively applicated in toddler or children,which greatly promoting the development of this vaccine.This review introduces the progress of polysaccharide conjugate vaccines.We introduce the typical polysaccharide conjugate vaccines currently on the market firstly,and then elucidate the protein carriers,the coupling chemistry methods and quality control that required in the preparation of polysaccharide conjugate vaccines.We can see that polysaccharide conjugate vaccine is a kind of vaccine with great development potential,which can be a sharp edge for us to prevent diseases.