A highly effective ferritin-based divalent nanoparticle vaccine shields Syrian hamsters against lethal Nipah virus.

The Nipah virus (NiV), a highly deadly bat-borne paramyxovirus, poses a substantial threat due to recurrent outbreaks in specific regions, causing severe respiratory and neurological diseases with high morbidity. Two distinct strains, NiV-Malaysia (NiV-M) and NiV-Bangladesh (NiV-B), contribute to outbreaks in different geographical areas. Currently, there are no commercially licensed vaccines or drugs available for prevention or treatment. In response to this urgent need for protection against NiV and related henipaviruses infections, we developed a novel homotypic virus-like nanoparticle (VLP) vaccine co-displaying NiV attachment glycoproteins (G) from both strains, utilizing the self-assembling properties of ferritin protein. In comparison to the NiV G subunit vaccine, our nanoparticle vaccine elicited significantly higher levels of neutralizing antibodies and provided complete protection against a lethal challenge with NiV infection in Syrian hamsters. Remarkably, the nanoparticle vaccine stimulated the production of antibodies that exhibited superior cross-reactivity to homologous or heterologous henipavirus. These findings underscore the potential utility of ferritin-based nanoparticle vaccines in providing both broad-spectrum and long-term protection against NiV and emerging zoonotic henipaviruses challenges.

Protective Efficacy of Inactivated Vaccine against SARS-CoV-2 Infection in Mice and Non-Human Primates.

The ongoing coronavirus disease 2019 (COVID-19) pandemic caused more than 96 million infections and over 2 million deaths worldwide so far. However, there is no approved vaccine available for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the disease causative agent. Vaccine is the most effective approach to eradicate a pathogen. The tests of safety and efficacy in animals are pivotal for developing a vaccine and before the vaccine is applied to human populations. Here we evaluated the safety, immunogenicity, and efficacy of an inactivated vaccine based on the whole viral particles in human ACE2 transgenic mouse and in non-human primates. Our data showed that the inactivated vaccine successfully induced SARS-CoV-2-specific neutralizing antibodies in mice and non-human primates, and subsequently provided partial (in low dose) or full (in high dose) protection of challenge in the tested animals. In addition, passive serum transferred from vaccine-immunized mice could also provide full protection from SARS-CoV-2 infection in mice. These results warranted positive outcomes in future clinical trials in humans.

Infection with novel coronavirus (SARS-CoV-2) causes pneumonia in Rhesus macaques.

The 2019 novel coronavirus (SARS-CoV-2) outbreak is a major challenge for public health. SARS-CoV-2 infection in human has a broad clinical spectrum ranging from mild to severe cases, with a mortality rate of ~6.4% worldwide (based on World Health Organization daily situation report). However, the dynamics of viral infection, replication and shedding are poorly understood. Here, we show that Rhesus macaques are susceptible to the infection by SARS-CoV-2. After intratracheal inoculation, the first peak of viral RNA was observed in oropharyngeal swabs one day post infection (1 d.p.i.), mainly from the input of the inoculation, while the second peak occurred at 5 d.p.i., which reflected on-site replication in the respiratory tract. Histopathological observation shows that SARS-CoV-2 infection can cause interstitial pneumonia in animals, characterized by hyperemia and edema, and infiltration of monocytes and lymphocytes in alveoli. We also identified SARS-CoV-2 RNA in respiratory tract tissues, including trachea, bronchus and lung; and viruses were also re-isolated from oropharyngeal swabs, bronchus and lung, respectively. Furthermore, we demonstrated that neutralizing antibodies generated from the primary infection could protect the Rhesus macaques from a second-round challenge by SARS-CoV-2. The non-human primate model that we established here provides a valuable platform to study SARS-CoV-2 pathogenesis and to evaluate candidate vaccines and therapeutics.

[Study on reproductive toxicity in male embryo rats with the pregnancy SD rates exposed by nonylphenol].

OBJECTIVE: To investigate the effect of nonylphenol (NP) exposure on the genital development of fetal male rats in pregnant rats, and to measure the mRNA and protein expression of insulin-like factor3 (Insl-3) in the testicular tissue of fetal rats. METHODS: A total of 100 pregnant SD rats were equally assigned to blank control group and four NP treated groups. Each rat in the NP treated groups received intragastric administration of NP at doses of 5, 40, 100, or 200 mg/kg/d from day 14 to 19 of gestation, and the rats in the blank control group received intragastric administration of pure peanut oil. The pregnant rats were sacrificed on day 19 of gestation. The body weight and testicular weight of each fetal rat were measured, and the descent of testis was also observed. The mRNA and protein expression of Insl-3 in the testicular tissue of fetal rats was analyzed by reverse transcription-PCR and Western blot. RESULTS: Compared with the blank control group, the 40, 100, and 200 mg/kg NP treated groups showed significantly decreased body weight and weight coefficient of testis (P < 0.05 or P < 0.01), significantly decreased testicular descent (P < 0.05), and significantly decreased mRNA and protein expression of Insl-3 (P < 0.05 or P < 0.01). CONCLUSION: Exposure to nonylphenol can lead to testicular maldevelopment, incomplete testicular descent, and Insl-3 expression downregulation of fetal male rats in pregnant rats.