This study was a meta-analysis of the literature on the efficacy and safety of tenofovir disoproxil fumarate (TDF) in preventing vertical transmission of hepatitis B in pregnancies with high viral load. Four observational studies and one randomized controlled trial involving 585 pregnant women and 595 newborns were included in the meta-analysis. TDF was more effective than the placebo in reducing vertical transmission in HBeAg-positive chronic hepatitis B (CHB) pregnancies with high serum HBV-DNA levels (OR = 0.21, 95% CI = 0.07-0.61) at 4-12 months, infant HBV DNA seropositivity at delivery (OR = 0.16, 95% CI = 0.07-0.37), and a severe flair in maternal alanine aminotransferase (ALT) levels (OR = 0.43, 95% CI = 0.19-0.95) during pregnancy. In addition, TDF showed more improvement in HBV DNA suppression at delivery (OR = 254.46, 95% CI = 28.39-2280.79). No significant differences were found in HBeAg seroconversion or ALT normalization; or in rates of cesarean section, emergent cesarean section, postpartum hemorrhage, prematurity, congenital malformations, or infant death. However, TDF induced more drug-related adverse events (OR = 2.33, 95% CI = 1.39-3.89) and elevated creatine kinase (CK) (OR = 9.56, 95% CI = 1.17-78.09) than in controls. The available evidence suggests that TDF is effective and safe in preventing vertical transmission of hepatitis B in pregnancies exhibiting a high viral load.

Virus-like particles (VLPs) can be used as powerful nanoscale weapons to fight against virus infection. In addition to direct use as vaccines, VLPs have been extensively exploited as platforms on which to display foreign antigens for prophylactic vaccination and immunotherapeutic treatment. Unfortunately, fabrication of new chimeric VLP vaccines in a versatile, site-specific and highly efficient manner is beyond the capability of traditional VLP vaccine design approaches, genetic insertion and chemical conjugation. In this study, we described a greatly improved VLP display strategy by chemoenzymatic site-specific tailoring antigens on VLPs surface with high efficiency. Through the transpeptidation mediated by sortase A, one protein and two epitopes containing N-terminal oligoglycine were conjugated to the LPET motif on the surface of hepatitis B virus core protein (HBc) VLPs with high density. All of the new chimeric VLPs induced strong specific IgG responses. Furthermore, the chimeric VLPs with sortase A tagged enterovirus 71 (EV71) SP70 epitope could elicit effective antibodies against EV71 lethal challenging as well as the genetic insertion chimeric VLPs. The sortase A mediated chemoenzymatic site-specific tailoring of the HBc VLP approach shows great potential in new VLP vaccine design for its simplicity, site specificity, high efficiency, and versatility.

Since 2013, the outbreak or sporadic infection of a new reassortant H7N9 influenza virus in China has resulted in hundreds of deaths and thousands of illnesses. An H7N9 vaccine is urgently needed, as a licensed human vaccine against H7N9 influenza is currently not available. Here, we developed a recombinant adenovirus-based vaccine, AdC68-H7HA, by cloning the H7N9 haemagglutinin (HA) gene into the chimpanzee adenoviral vector AdC68. The efficacy of AdC68-H7HA was evaluated in mice as well as guinea pigs. For comparison, an H7N9 DNA vaccine based on HA was also generated and tested in mice and guinea pigs. The results demonstrated that both AdC68-H7HA and the DNA vaccine prime-adenovirus boost regimen induced potent immune responses in animals and completely protected mice from lethal H7N9 influenza viral challenge. A post-immunization serum transfer experiment showed that antibody responses could completely protect against lethal challenge, while a T cell depletion experiment indicated that HA-specific CD8+ T cells responses also contributed to protection. Therefore, both HA-specific humoral immunity and cellular immunity play important roles in the protection. These data suggest that the chimpanzee adenovirus expressing HA is a promising vaccine candidate for H7N9 virus or other influenza viral subtypes.