Study On Antibody Level Against China Epidemic Strains In Population Serum

Influenza virus causes severe respiratory disease among humans and animals,even leads to death. By far, influenza has became a global public hygiene problem which seizes the world’s attention.Influenza virus antibody in human serum can provide certain protection in influenza viruses invasion, whose existence is considered as a proof that weather immune pro-tection was acquired after virus infection. Therefore, studying influenza virus antibody level of population serum could com-prehend herd immunity ability of population against influenza virus, offer further theoretical instruction for influenza virus’prevention and control.We collected more than 800 samples of healthy physical examination population serum in this study, Hemagglutinin inhibition test was performed to detect antibody level against domestic epidemic strain in current year, found that protection ratio of antibody against epidemic strain H1N1, H3N2, By, Bv are junior group:51.11%,99.12%, 4.44%,0%;senior group:46.27%,97.85%,6.01%,4.55%;senile group:24.15%, 98.51%,5.08%,3.38%, respectively.The protection ratio of influenza A virus antibody was higher than influenza B virus antibody. In different age groups, the protection ratio of influenza virus antibody of junior group and senile group is relatively low, indicates the youth and the aged are at high risk of influenza virus infection and vaccination is necessary.Due to the high mutation of influenza virus, the epidemic status of influenza virus varies in different years or different regions. Consequently, World heath organization(WHO) re-commends influenza virus vaccine strain for next year to various countries every year according to the surveillance. In order to understand weather virus strain provided by WHO could reflect influenza antigen mutation and prevalence accurately, we have sequenced surface antigen segment HA of epidemic strain, aligned domestic epidemic strain and vaccine strain re-commended by WHO and drawn cladograms, found epidemic strain in China differs from virus strain recommended by WHO evolutionarily. It is vital to further evaluate the difference of cross neutralizing antibody between vaccinated serum and epi-demic strain serum in China to determine if it is necessary to produce influenza vaccine by Chinese epidemic strain.This study has laid the foundation of influenza virus vaccine produced by Chinese epidemic strain for better immune pro-tection in Chinese population by observing immunity of anti-body against 2014th influenza virus Chinese epidemic strain in population.In addition, this paper evaluated immunity of antibody against H5N1 influenza virus. Protection ratio of junior, senior and senile group are 3.33%,7.86%,6.80% and antibody GMT is 1:5.983,1:11.037,1:8.910, respectively.