Acute hepatitis E virus (HEV) is associated with viremia and faecal excretion of the virus. The information on duration and temporal pattern of viremia and faecal shedding in HEV infection is important, but is not available. Serial serum and stool specimens were collected from patients with acute hepatitis E (typical clinical picture, serum alanine aminotransferase levels > 5‐folds the upper limit of normal and presence of IgM anti‐HEV), beginning from within 7 days of the onset of symptoms. HEV RNA concentrations were measured in sera and 10% stool suspensions, using a real‐time Taqman‐based nucleic acid amplification assay. Seventeen patients (median age 25 [range 19‐61] years; all men) were enrolled within a median of 5 (range 3‐8) days of the onset of the first symptom and provided 113 serum specimens and 71 stool specimens. The median (range) highest levels of serum bilirubin, alanine aminotransferase and aspartate aminotransferase in the patients were 10.3 (5.9‐43.4) mg/dL, 1817 (442‐4642) IU/L and 1016 (88‐4561) IU/L, respectively. All the 17 patients had demonstrable viremia, and 12 of the 13 patients who were tested had faecal excretion at one or more time points. The HEV RNA titres were the highest in the early phase of disease and declined rapidly with time, becoming nondetectable in the serum by day 20 and in the stool by day 21. In most of the patients with acute uncomplicated acute hepatitis E, the degree of viremia and faecal shedding decline quickly after the onset of clinical illness and rapidly disappear in parallel with each other.

The SARS-CoV-2 infection spread rapidly throughout the world and appears to involve in both humoral and cell-mediated immunity. SARS-CoV-2 is attached to host cells via binding to the viral spike (S) proteins and its cellular receptors angiotensin-converting enzyme 2 (ACE2). Consequently, the S protein is primed with serine proteases TMPRSS2 and TMPRSS4, which facilitate the fusion of viral and cellular membranes result in the entry of viral RNA into the host cell. Vaccines are urgently required to combat the coronavirus disease 2019 (COVID-19) outbreak and aid in the recovery to pre-pandemic levels of normality. The long-term protective immunity is provided by the vaccine antigen (or pathogen)-specific immune effectors and the activation of immune memory cells that can be efficiently and rapidly reactivated upon pathogen exposure. Research efforts aimed towards the design and development of vaccines for SARS-CoV-2 are increasing. Numerous coronavirus disease 2019 (COVID-19) vaccines have passed late-stage clinical investigations with promising outcomes. This review focuses on the present state and future prospects of COVID-19 vaccines research and development, with a particular emphasis on immunological mechanisms of various COVID-19vaccines such as adenoviral vector-based vaccines, mRNA vaccines, and DNA vaccines that elicits immunological responses against SARS-CoV-2 infections in humans.

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T-cell acute lymphoblastic leukemia (T-ALL) is a genetically heterogeneous disease, characterized by an abnormal transformation of T cells into highly proliferative leukemic lymphoblasts. Identification of common genetic alterations has provided promising opportunities for better risk stratification in T-ALL. Current treatment in T-ALL still poses the major challenge of integrating the knowledge of molecular alterations in the clinical setting. We utilized the Multiplex Ligation Dependent Probe Amplification (MLPA) method to determine the frequency of common copy number alterations (CNAs) in 128 newly diagnosed T-ALL patients. We also studied the association of these CNAs with patient's clinical characteristics and survival. The highest frequency of deletion was observed in CDKN2A (59.38%), followed by CDKN2B (46.88%), LMO1 (37.5%), and MTAP (28.12%). PTPN2 (22.66%), PHF6 (14.06%), and MYB (14.06%) had the highest number of duplication events. A total of 89.06% patients exhibited CNAs. STIL::TAL1, NUP214::ABL1, and LMO2::RAG2 fusions were observed in 5.47%, 3.12%, and 0.78% of patients, respectively. CDKN2A, CDKN2B, and PTPN2 gene deletions were mainly observed in pediatric patients, while CNAs of NF1 and SUZ12 were observed more frequently in adults. In pediatric patients, alterations in CDKN2B, CASP8AP2, and AHI1 were associated with poor prognosis, while SUZ12 and NF1 CNAs were associated with favorable prognosis. In adult patients, ABL1 CNA emerged as an independent indicator of poor prognosis. The observed molecular heterogeneity in T-ALL may provide the basis for variations observed in clinical response in T-ALL and MLPA based CNA detection may help in risk stratification of these patients.

In the study population, the 157insMTTTVP variant of HAVCR1 gene was not associated with more severe outcome of HAV infection. Further studies in other populations around the world are needed to assess the relation of this genetic variation with disease outcome.