Further-attenuated measles vaccine: virus passages affect viral surface protein expression, immunogenicity and histopathology pattern in vivo.

Measles vaccine viruses Leningrad-16 (L-16) and Moscow-5 (M-5, an L-16-derived clonal variant), at passage levels used for vaccination and after ten further low-multiplicity passages on quail embryo (QE) cells, were compared for (1) immunogenicity, (2) histopathological lesions induced in vivo and (3) surface protein expression within infected cells and on the virion surface. At the 10th passage, viruses evoked a poorer neutralizing antibody response in guinea pigs, induced an earlier appearance of more pronounced pathological lesions and replicated faster in Vero cells than the original viruses. H protein expression increased 1.

[Experimental measles infection in rodents].

The sensitivity of newborn hamsters to inoculation with the vaccine L-16 strain of measles virus and the Lec strain isolated from a patient with subacute sclerosing panencephalitis as well as the possibility of persistence of these viruses in the animals were studied. Intracerebral inoculation of the L-15 strain was shown to produce in hamsters acute meningoencephalitis leading to death in 85%-100% of cases. Over 30 days after inoculation, the infectious virus, the virus-specific antigen and virus genome were found in the brain.

[Comparative clinico-morphological research on measles and mumps infections in an experiment on guinea pigs].

The pathological process typical of measles and mumps infections was reproduced clinically and morphologically in 250 experimental guinea pigs infected into the anterior eye chamber with different strains of measles and mumps viruses. The intraocular inoculation of measles virus induced in guinea pigs the signs of iridocyclitis and follicular conjunctivitis, whereas inoculation of mumps virus induced dacryoadenitis as well as iridocyclitis and follicular conjunctivitis. The severity of the reproduced process and its dynamics correlated with the pathogenicity of measles and mumps virus strains used in the experiment.

Comparative clinico-morphological investigations of the CNS of monkeys and of the eye teguments of guinea pigs infected with different measles virus strains.

Measles virus strains Edmonston and L-16 have been studied in 10 intracerebrally (i.c.) infected monkeys and in 155 guinea pigs infected into the anterior eye chamber.

Pathomorphologic characterization of CNS damage in monkeys infected with persistent variant of measles virus vaccine strain L-16.

The lesions of CNS were examined in monkeys infected intracerebrally (i.c.) with a variant of measles virus vaccine strain L-16 isolated after prolonged persistence in human cell culture NEr-2.