PRIMARY AND SECONDARY INFECTIONS BY ASIAN AND AMERICAN GENOTYPES OF DENGUE 2 VIRUS IN MACACA FASCICULARIS MONKEYS

Department of virology, PAHO/WHO Collaborating Center for the Study of Dengue and its Vector, "Pedro Kourí" Tropical Medicine Institute, Autopista Novia del Mediodía, km 6 P.O. Box 601 Marianao 13, Havana, Cuba, Center for Genetic Engineering and Biotechnology, Apdo 6162. Havana 10600, Cuba

^* To whom correspondence should be addressed. Email: lupe{at}ipk.sld.cu.

	Abstract

This study aims at comparing the immune response and the protection capacity induced by the DENV-2 American and Asian genotypes in Macaca fascicularis monkeys. Animals were primary infected with American or Asian DENV-2 strains and challenged one year later with a DENV-2 Asian genotype strain. The viremia and monkey antibody levels were similar among the strains after primary and secondary infection; however, the functionality of such antibody response was different. A limited viral replication was demonstrated after the secondary infection in all the monkeys. No virus was isolated in tissue culture while RT-PCR showed a late positive reaction in 4 of 5 challenged monkeys. The IgM response pattern and the detection of antibodies to specific proteins by Western blot test supported the protection data. In spite of demonstrating the protective effect after homologous challenge, a strong anamnestic antibody response was observed.