Development of an efficient hiv vaccine has paradoxically been hampered by a malfunction of viral reverse transcriptase . During the reverse transcription process , it makes numerous errors that result in a high rate of mutations in the epitopes (amino acids of an antigen recognized by the histocompatibility complex). This causes the virus to escape the specific immune response . If we also add the frequent recombination events to the reverse transcriptase errors,
new subtypes and mosaic viruses are originated .that leave the immune system practically without ammunition in the face of this fierce battle. Mosaic vaccine: a preventive vaccine against hiv-1 in recent years, the janssen subsidiary of the johnson & johnson fax number list company has focused on developing effective vaccines against hiv. These are called mosaic vaccines. These are rna vaccines based on an adenovirus vector (vad26) encoding computationally optimized epitope sequences to capture the global diversity of hiv-1 variants .
Specifically, the antigens expressed in one of these vaccines (ad26.mos.hiv) belong to the env, gag and pol genes (respectively they code for spike proteins, structural proteins of the virus and proteins involved in transcription and the life cycle of the virus ). Virus). Early phases of double-blind clinical trials , conducted at 12 clinics located in east africa, south africa, thailand, and the united states, showed promising results. The mosaic vaccine was shown to trigger both a humoral (antibody production) and a cellular ( t-lymphocyte action) response. The tests carried out in monkeys