Reference no: EM132520534

1. Great effort is now being directed at developing vaccines for the SARS-COV-2 (CoVid-19). If in one study, it was reported that antibodies against a particular epitope of a specific viral protein was protective. The structure of this epitope was determined to be a peptide that is 10 amino acids in length. This peptide was synthesized and used to immunize individuals exposed to the pathogen. Disappointingly, no protection was seen. Can you suggest any reasons for this failure?

2. It is well established that some of the indigenous populations in Australia have only few V genes for the L (2 genes) and H (3 genes) chains of the Ig. Nevertheless, they seem healthy and able to resist the diversity of pathogenic organisms endemic to the area. Suggest how this might be accomplished.

3. A gas station attendant was brought to the hospital suffering from excessive bone marrow aplasia due to long-term exposure to benzene. All blood elements are at low levels and death is imminent. The man and a sibling were rapidly typed as both being A cf11+ cf1Rhcf11+cf1, HLA-A3,7: B4,8, and bone marrow was transfused. Within few days the RBC count rose, indicating a successful take. However, 3 weeks later he began to experience diarrhea along with skin rashes on the palms, soles of the feet and the trunk. This was followed by jaundice and enlarged liver and spleen. Administration of an anti-CD3 monoclonal antibody plus cyclosporine produced some improvement. What went wrong, and why?