• Vaccine Name: G. lamblia vaccine encoding a-enolase
• Target Pathogen: Giardia lamblia
• Type: Live, attenuated vaccine
• Status: Research
• Host Species for Licensed Use: Human
• Antigen: alpha-enolase - Enolase is one of the most abundantly expressed enzymes in the cytosol of a variety of organisms and its mRNA transcript is highly expressed in Giardia trophozoites. In Giardia, enolase is specifically secreted from trophozoites in the presence of intestinal epithelial cells(Castillo-Romero et al., 2012).
• Immunization Route: Intramuscular injection (i.m.)
• Description: An a-enolase based heterologous vaccine utilizing an attenuated, recombinant Salmonella vaccine as a vehicle(Jenikova et al., 2011)

Mouse Response

• Host Strain: BALB/c
• Host age: 8 weeks
• Host gender: Female
• Vaccination Protocol: Female BALB.c mice were fasted for 3h and given 109 CFU of the Salmonella vaccine strain or vector control by oral gavage in 200 ul of a buffer. Immune boosting was performed by 10ug of cholera toxin with live vaccine vectors in both immunizations or sublingual administration of 15 ug purified recombinant antigen followed immediately by oral gavage of live vaccine vector. A second immunization was given two weeks later. Six weeks after the second immunization, mice were infected with G.lamblia trophozoites by oral gavage. (Jenikova et al., 2011)
• Immune Response: The vaccine strain expressing a1-giardin elicited high levels of specific IgG in the serum, indicating that the vaccine was strongly immunogenic in vivo. It also simulated strong antibody responses to the Salmonella antigens. It also elicited IgA responses to a-enolase.(Jenikova et al., 2011)
• Challenge Protocol: Mice were immunized orally twice two weeks apart and were challenged orally six weeks later with G.lamblia GS/M trophozoites. Four days after infection, trophozoite numbers in the small intestine were determined. The a-enolase vaccine had no significant protective effect under the same conditions. (Jenikova et al., 2011)