Reverse Vaccinology and Immunoinformatic Approach for Designing a Bivalent Vaccine Candidate Against Hepatitis A and Hepatitis B Viruses

Hepatitis A and B are two crucial viral infections that still dramatically affect public health worldwide. Hepatitis A Virus (HAV) is the main cause of acute hepatitis, whereas Hepatitis B Virus (HBV) leads to the chronic form of the disease, possibly cirrhosis or liver failure. Therefore, vaccination has always been considered the most effective preventive method against pathogens. At this moment, we aimed at the immunoinformatic analysis of HAV-Viral Protein 1 (VP1) as the major capsid protein to come up with the most conserved immunogenic truncated protein to be fused by HBV surface antigen (HBs Ag) to achieve a bivalent vaccine against HAV and HBV using an AAY linker. Various computational approaches were employed to predict highly conserved regions and the most immunogenic B-cell and T-cell epitopes of HAV-VP1 capsid protein in both humans and BALB/c. Moreover, the predicted fusion protein was analyzed regarding primary and secondary structures and also homology validation. Afterward, the three-dimensional structure of vaccine constructs docked with various toll-like receptors (TLR) 2, 4 and 7. According to the bioinformatics tools, the region of 99-259 amino acids of VP1 was selected with high immunogenicity and conserved epitopes. T-cell epitope prediction showed that this region contains 32 antigenic peptides for Human leukocyte antigen (HLA) class I and 20 antigenic peptides in terms of HLA class II which are almost fully conserved in the Iranian population. The vaccine design includes 5 linear and 4 conformational B-cell lymphocyte (BCL) epitopes to induce humoral immune responses. The designed VP1-AAY-HBsAg fusion protein has the potency to be constructed and expressed to achieve a bivalent vaccine candidate, especially in the Iranian population. These findings led us to claim that the designed vaccine candidate provides potential pathways for creating an exploratory vaccine against Hepatitis A and Hepatitis B Viruses with high confidence for the identified strains.

Status of Immunity Against the Hepatitis A Virus in Healthy Population: A Report From Southeastern Iran

Background: Recently, epidemiological studies on hepatitis A virus (HAV) infection showed the seroprevalence has been changing due to changes in lifestyle. To the best of our knowledge, there have been no published data on the seropositivity of HAV in Zahedan, southeastern Iran. Objectives: This study aimed to investigate the seroprevalence of HAV immunoglobulin G (IgG) antibody in Zahedan, southeastern Iran, to provide the required information for better planning in preventive strategies. Methods: In this cross-sectional study, using the available sampling method, a total of 250 serum samples (18 years and above) in both the urban and rural areas of Zahedan were evaluated for anti-HAV IgG by enzyme-linked immunosorbent assay. Results: Based on the results, it was observed that 228 out of 250 (91.2%) serum samples were positive for HAV IgG antibody. Male gender, family size, parents’ education, mother’s occupation, and history of jaundice before the age of 12 years were associated with positive HAV antibody (P < 0.001). The seroprevalence HAV rates were not statistically different between the residents of urban and rural regions. Conclusions: The seropositivity of HAV is high in both the urban and rural areas of Zahedan, Iran. Therefore, the HAV vaccination of the general population is not necessary. It is recommended to monitor HAV seroprevalence in the general population to determine high-risk groups, including anti-HAV seronegative individuals, for HAV vaccination in the residents of the southeast border.

The Seroprevalence of Hepatitis A Virus (HAV) Among Blood Donors Presenting to the Iranian Blood Transfusion Organization in Sanandaj, Iran

Background: Hepatitis A virus (HAV) infection is endemic in Iran. Detection of the seroprevalence of HAV is necessary to evaluate the feasibility of infection control strategies in the population. Objectives: This study aimed to determine the seroprevalence of HAV among blood donors as a representative sample of the general population. Methods: In this cross-sectional study, 268 blood samples were randomly selected from donors, presenting to the Iranian Blood Transfusion Organization in Sanandaj, Iran, in 2019. The collected sera were measured for anti-HAV antibodies (IgG and IgM), using ELISA assays. Also, demographic data, including age, gender, marital status, education, occupation, and blood donation status, were collected. The test results and demographic data were analyzed in STATA software. Results: The mean age of the blood donors was 37.79 ± 10.64 years, and 88.43% of them were male. Out of 268 blood samples, 218 (81.34%) were positive for anti-HAV antibodies. The antibody positivity was significantly correlated with age (P = 0.014) and marital status (P = 0.027). The majority of anti-HAV positive cases were found among farmers and ranchers (93.33%) (P = 0.045). Conclusions: A large proportion of blood donors had anti-HAV antibodies and were immune to HAV infection. Therefore, HAV was endemic in the study area.