ABSTRACT
COVID-19 (Corona virus 2019) is a disease caused by SARS-CoV-2 (Severe Acute Respiratory Syndrome) that can trigger what is called a respiratory tract infection. The oxford-AstraZeneca vaccine is produced by Oxford University in Co-operation with the British-Swedish company AstraZeneca, along with its Indian version, which is called Covishield. Oxford AstraZeneca is a vector vaccine that utilizes a vector based on the recombinant ChAdOx1 of chimpanzees. The Covid-19 vaccine is intended to provide immunity against the disease caused by SARS-CoV-2. It is given to individuals > 18 years in two doses (standard doses, “SD/SD”). This study was carried out to investigate the changes induced by Oxford-AstraZeneca vaccine on the liver in a rat model. A total of thirty (30) weighing between 157g-318g were randomly assigned into groups (A, B, C, D, E & F) of five (5) rats per group. Group A served as Control while Group B, C, D, E, & F served as treatment groups. The rats had free access to grower mash feed and water throughout the entire study period. Group A which served as control were administered 0.2ml 0f Sterile Injection water; Group B, C, D, & E were intramuscularly vaccinated with Oxford-AstraZeneca respectively and Group F was vaccinated with Oxford-AstraZeneca vaccine and also induced with 0.4ml of Alloxan. The rats were sacrificed and their liver were harvested and immediately fixed in 10% of formal saline for tissue processing. Haematoxylin and Eosin stains were used for the histological staining. Results show there was no significant increase in hepatic weight and hepatosomatic index. There was significant increase in group A and D when the initial and final body weights were compared. In liver function tests, there was significant increase in group B and F and significant decrease in group D and E in the charts showing the levels of Alanine aminotransferase and Alkaline Phosphatase when compared to the control group. In charts showing the levels of Aspartate aminotransferase, there was significant increase in group F and significant decrease in group D and E when compared to the control group. In the chart showing the level of total bilirubin, there was significant increase in group B and F and a significant decrease in group C when compared to the control group. In charts showing the levels of conjugated bilirubin and albumin, there was significant increase in group B and F and a significant decrease in group D and E when compared to the Control group. And in oxidative stress, there was increase across all the groups in total protein and MDA. In charts showing the levels of GPx and GSH, there was significant increase in group B, C, and E and significant decrease in group D and F. In charts showing the levels of catalase and SOD, there was increase in group C and decrease in group D and F. Histological slides showed there was vascular congestion, periportal mobilization of lymphocytes and activation of kupffer cells. Oxford AstraZeneca vaccine had no effects on rats that were sacfrificed on the 13th, 28th, 59th and 90th day respectively
