Application Of MAPREC Technique In The Detection Of The Virulence Of Sabin Strains Of Poliomyelitis Vaccine

With the global polio eradication process forward,in order to avoid the generation of polio vaccine associated paralysis(VAPP)and polio vaccine derived virus(VDPV),WHO recommends the use of Inactivated Poliovirus Vaccine(IPV)to gradually replace OPV for immunization,this is also the requirement of "Global polio eradication strategy final plan".In the process of sIPV production,both the virus species and vaccines must be kept in the characteristics of attenuated strains,and their nerve toxicity should be strictly controlled.Monkey somatic toxicity test(MNVT)is considered as an important indicator and standard method for evaluating the toxicity of Sabin strain and Sabin strain vaccine.But monkey resources are limited,cost is high,and related to ethical issues.MAPREC technology refers to the method of analyzing mutations by polymerase chain reaction and restriction enzyme pyrolysis,it can reduce the cost and reduce the use of test animals.which is mainly used for screening before neurovirulenc test.At present,there are more researches on MAPREC methods in foreign laboratories,there are studies in China,but no reports have been reported,with the progress of the global polio eradication program,a large number of vaccines need to be tested for neurovirulence,WHO encourages research into the MAPREC technology.Objective:Using the MAPREC to test the mutation of Neurovirulence determinate sites of the virus harvest during the production process of inactivated poliovirus vaccine for Sabin strain,make sure the vaccine is safe and effective.Methods:?Using the MAPREC technology to detect the mutation rate of the Neuro virulence determinate sites of Sabin 1(480-A.525-C),11(481-C)and Pfizer 111(472-C)virus harvest by the bioreactor culture.?Changing the temperature,MOI,generations of virus replacation by the T-flask culture,Observe the change in mutation rate.Results:MAPREC could detect the lower mutation rate of sIPV in the normal culture condition,After the sIPV virus culture conditions change,MAPREC detected Neurovirulence determinate sites mutation also changed.Conclusion:MAPREC test can rapidly and effectively detect the gene mutation rate of polio vaccine virus harvesting fluid,so as to determine whether the vaccine's neurovirulence is passed the standard to ensure that a safe and effective vaccine is produced.