Unvaccinated Infection Research Articles

Evaluation of crude adult Ascaris suum intestinal tract homogenate in inducing protective IgG production against A. suum larvae in BALB/c mice

Globally, ascariasis ranks as the second leading intestinal helminth infection. However, progress in developing better control strategies, such as vaccines, remains slow-paced. This study aims to measure antibody production and parasite load in male BALB/c mice immunized with crude Ascaris suum intestinal tract homogenate.Thirty-two (32) mice were randomized into: (1) unvaccinated, uninfected (UU); (2) unvaccinated, infected (UI); (3) vaccinated, uninfected (VU); and (4) vaccinated, infected (VI) groups. A 100-μL vaccine containing 50 μg of homogenized A. suum intestines and Complete Freund's Adjuvant (1:1) were introduced intraperitoneally. Immunizations were done on days 0, 10, and 20. Oral gavage with 1000 embryonated eggs was done on day 30. Blood was obtained at day 40. To measure serum IgG levels, indirect ELISA was done. Microtiter plates were coated with 100 μg larval homogenate, and HRP-conjugated anti-mouse IgG was used as secondary antibody. Parasite load was measured in lung and liver tissues.Tukey's HSD of signal to cut-off ratios of absorbance readings obtained in indirect ELISA procedure for the 1:200 serum dilution showed statistically significant difference between the UU and VI (p = 0.026) as well as between UI and VI (p = 0.003) groups. No statistically significant difference in parasite load was observed in the lungs (p = 0.074), liver (p = 0.130), and both lungs and liver (p = 0.101).Immunization elicited a significant larva-directed IgG production. However, there is no significant difference in parasite loads in either lung or liver tissues across all treatment groups as the larval counts obtained from the study were very low and may not be indicative of the actual parasite load in mice.

Haematological changes in Isa-brown laying chickens (<i>Gallus gallus domesticus</i>) experimentally infected with velogenic Newcastle disease virus

This study investigated the haematological changes in vaccinated and unvaccinated laying chickens experimentally infected with a velogenic Newcastle disease virus. Two hundred and forty laying chickens were randomly assigned into four groups of 60 each: vaccinated with Newcastle disease vaccines and infected with velogenic Newcastle disease virus (VI), vaccinated uninfected (VU), unvaccinated infected (UI), unvaccinated uninfected (UU). At peak production, 32-weeks-old, groups VI & UI were each inoculated intramuscularly with 0.2 ml of velogenic Newcastle disease virus. The changes in the blood cells were assayed in the groups on the specified days. The total red blood cell count (RBC) was significantly (P 0.05) differences between the PCV, RBC and HbC in VI & VU groups from day 0 to 21 PI. The leukogram showed significant (P < 0.05) differences in leukocytosis on days 3 & 6 PI followed by significant (P < 0.05) leukopenia on days 10, 15 & 21 PI in UI group. However, significant leukocytosis on day 10 PI followed by leukopenia on day 15 PI were recorded in VI group. These findings suggest that leukocytosis in UI & VI and decreased haemogram in UI are features of Newcastle disease in laying chickens. Keywords: Experimental infection, Haematology, Laying chickens, Leukocytosis, Newcastle disease