Immunogenicity And Safety Of Concomitant Inoculation Of Measles And Rubella Combined Live Vaccine And Japanese Encephalitis Attenuated Live Vaccine In Zhejiang Province

1.BackgroundMeasles,an infectious disease caused by the measles virus,fever,respiratory tract catarrh symptom and maculopapule rash are clinical symptoms.Historically,death caused by measles is the highest among all vaccine preventable diseases,especially to the children.Measles is highly contagious,and the basic reproductive number is 16-18.It is very easy to cause outbreaks in the population without measles immunization,which is a legal Class B infectious disease.Japanese encephalitis(JE)is an acute infectious disease caused by Japanese encephalitis virus,which is transmitted by mosquitoes.The mortality and disability rate of JE are very high.It is an infectious disease that threatens public health,especially children.It is a legal Class B infectious disease.Vaccination is the most economical and effective means of preventing and controlling infectious diseases.Many countries have included measles vaccines in child immunization programmes.The widespread use of JE vaccine has led to a significant decline in the incidence of Japanese encephalitis in countries such as Japan and South Korea and parts of China over the past few decades.JE vaccine has also been incorporated into immunization programmes in a growing number of endemic countries and regions.At this stage,China's routine immunization program requires children to receive one dose of measles and rubella attenuated live vaccine at 8 months of age,and one dose of measles mumps and rubella live attenuated vaccine at 18-24 months.The Japanese encephalitis attenuated live vaccine is given the first dose at 8 months of age and the second dose at 2 years old.The initial immunization schedule of the two vaccines in China is at the same time.There is an opportunity for simultaneous vaccination when 8 months old.In the practice in Zhejiang Province,the vaccination program adopted by the vaccination clinic is not the same.They also concerned about the safety and efficacy of simultaneous vaccination of these two vaccines.At present,the research carried out in this area is relatively limited and there is no conclusion.On the other hand,most of the vaccine-based immunizations for children are completed within one year old,and the number of doses is up to ten doses.In order to reduce the frequency of visits to the vaccination clinics,the actual vaccination procedure is more convenient and does not affect the immunogenicity.Under the premise of vaccine immunogenicity and safety,adopting the combined vaccination strategy of live attenuated JE vaccine is a good means to improve the vaccination compliance of small-month-age children.Therefore,this research has a very good practical significance.2.ObjectiveTo evaluate the immunogenicity and safety of concomitant inoculation of Measles and Rubella Combined Live Vaccine and Japanese encephalitis attenuated live vaccine,and provide reliable scientific evidence for designing the immunization schedule.3.MethodsSome healthy children aged 8 months in selected cities in Zhejiang Province were randomly,controlled,and open(non-blind)non-inferiority trials.The questionnaire was used to collect basic information of children,and children were randomly assigned to the MR and LJEV combined vaccination group(the experimental group),and the MR single vaccination group(the control group)was taken before the exemption and 6 weeks after the exemption.Peripheral venous blood 1ml was used as serum antibody test for measles and rubella,and the levels of measles and rubella antibodies before and after vaccination were evaluated.The safety of combined vaccination was evaluated.Measles and rubella IgG antibodies were detected by enzyme-linked immunosorbent assay(ELISA).Data were double-entry with Epidata and statistical analysis was performed using Epi Info epidemiological statistical analysis software.4.ResultsThe results showed that no severe adverse event occurred in two groups,clinical reactions in each inoculation group were mild.The seroconversion rate of measles antibody and rubella antibody were 96.43%and 88.49%in the experimental group after vaccination,the geometrical mean concentrations(GMC)of measles antibody was 1539.94 mIU/ml and the GMC of rubella antibody was 47.65 mIU/ml after concomitant inoculation;the seroconversion rate of measles antibody and rubella antibody were 97.62%and 86.11%in the control group,the GMC of Measles antibody was 1428.96mIU/ml and the GMC of Rubella antibody was 45.66 mIU/ml after MV inoculation.No difference were detected in two groups of seroconversion rate of measles antibody and rubella antibody and GMC after vaccination.5.ConclusionThe immunogenicity and safety is equivalent when MR and LJEV were simultaneous inoculation or MR immunization seperately,it can be used among children's immunization programm.