[Horizontal transmission of live attenuated hepatitis A vaccine virus].
OBJECTIVE
To investigate the horizontal transmission of virus after inoculation with live attenuated hepatitis A vaccine.


METHODS
One hundred and ninety nine children aged 4 approximately 7 years without anti-HAV and with normal ALT level have been screened out at two trial fields in Anning, Kunming and divided into vaccine group (82 children) and contact group (117 children) to observe the horizontal transmission of the live attenuated hepatitis A vaccine virus (H2 strain). Four supernatant specimens of HAV positive fecal suspension derived from individual vaccines and contacts were taken and injected intravenousely into 8 common marmoset (Callithrix jacchus) for detecting the virulence level of HAV.


RESULTS
The rates of seroconversion were 97.6% (80/82) for vaccine group 6 weeks after inoculation and 13.7% (16/117) for contact group at the ninth week of observation. The detection rates of fecal HAV were 89.5% (34/38) and 70.7% (53/75), respectively. No liver functional abnormality has been found in either groups. The responses of 8 marmosets separately infected with fecal shedding HAV of 2 vaccines and 2 contacts have been examined with neither elevations of serum liver enzyme nor liver histopathological changes but delay seroconversions as well as low titers of anti-HAV.


CONCLUSIONS
The safety and immunogenicity live attenuated hepatitis A vaccine (H2 strain) were good. The vaccine virus could actively propagate but keep the stability of attenuated characteristics in human bodies, and might result in horizontal transmission but not induce hepatitis A in crowd.
Huang
X
X
Institute of Medical Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Kunming 650118, China.
Cao
Y
Y
Tan
S
S
D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D002144:Callithrix; D002648:Child; D002675:Child, Preschool; D018562:Disease Transmission, Infectious; D005243:Feces / Q000821:virology; D005260:Female; D006506:Hepatitis A / Q000517:prevention & control / Q000635:transmission*; D022362:Hepatitis A Vaccines / Q000008:administration & dosage* / Q000276:immunology; D030041:Hepatitis A virus / Q000276:immunology; D006801:Humans; D008297:Male; D013997:Time Factors; D014613:Vaccines, Attenuated / Q000008:administration & dosage / Q000276:immunology
D000914:Antibodies, Viral; D022362:Hepatitis A Vaccines; D014613:Vaccines, Attenuated