Accession Number : AD0428950


Title :   SEQUENTIAL IMMUNIZATION PROCEDURE AGAINST GROUP B ARBOVIRUSES.


Descriptive Note : Annual progress rept., 1 Feb 63-1 Feb 64,


Corporate Author : JOHNS HOPKINS UNIV BALTIMORE MD SCHOOL OF HYGIENE AND PUBLIC HEALTH


Personal Author(s) : Price,Winston H


Report Date : 01 Feb 1964


Pagination or Media Count : 1


Abstract : A strain of Japanese B encephalitis virus has been partially attenuated in its virulence for rhesus monkeys by chick embryo passage. This partially attenuated strain gives excellent protection in monkeys against challenge of virulent Japanese B virus using lowering of viremia and absence of neuropathology as criteria of protection. It also protects against St. Louis encephalitis virus. A combination of 17D yellow fever vaccine plus dengue 4 virus gives protection in monkeys against a challenge of dengue 1 virus. The subcutaneous or oral administration of Langat virus to spider monkeys protects them against challenges by Russian spring summer encephalitis virus or Omsk hemorraghic fever virus. This protection lasts at least 22 months. Data from various types of experiments indicate that two basic mechanisms are important in conferring protection in the sequential immunization procedure. One requires the initial presence of circulating neutralizing antibody. The second mechanism depends on the sensitization of the immune mechanisms of the host by the virus vaccines so that in the absence of detectable neutralizing antibody the host responds with an anamnestic response in neutralizing antibody when challenged by heterologous group B viruses. It is this latter mechanism that appears to be important in long lasting immunity. (Author)


Descriptors :   *ENCEPHALITIS , VIRUSES , IMMUNITY , ANTIGENS , ANTIBODIES , VIRUSES , SENSITIVITY , PRIMATES , NEUROLOGY , PATHOLOGY


Distribution Statement : APPROVED FOR PUBLIC RELEASE