Provided herein are polynucleotides encoding Lassa virus glycoprotein or Lassa virus nucleoprotein, or a chimeric protein comprising the ectodomain of Lassa virus glycoprotein and the transmembrane and cytoplasmic domains of NDV F protein. Also, provided herein are recombinant Newcastle disease virus (NDV) comprising such a polynucleotide, and immunogenic compositions comprising such recombinant NDV. Further, provided herein are methods for immunizing against Lassa virus comprising administering the recombinant NDV or an immunogenic composition thereof.

A recombinant vaccine is described, which comprises an active Newcastle disease viral vector (NDV) having inserted an exogenous nucleotide sequence of severe acute respiratory syndrome coronavirus 2 (SARS-COV-2), without adjuvant, capable of generating a significant cellular response in T cells (CD4+ or CD8+) when stimulated with the S protein of the SARS-CoV-2 virus or proteins derived from it in individuals with previous immunity.

The present disclosure provides a recombinant herpesvirus of turkeys (HVT) and a preparation method and use thereof. The present disclosure specifically provides a recombinant HVT, where an exogenous gene is inserted in a spacer region between an HVT005 region and an HVT006 region of an HVT genome; and the exogenous gene is selected from a gene derived from the group consisting of a Newcastle disease virus (NDV), an avian influenza virus (AIV), and an infectious bursal disease virus (IBDV); the spacer region between an HVT005 region and an HVT006 region of an HVT genome is located between 8,867 nt and 9,319 nt of the HVT genome, and has a nucleotide sequence set forth in SEQ ID NO: 1.

The present specification provides: a Newcastle disease virus with improved heat resistance; a Newcastle disease vaccine comprising the virus; a polypeptide comprising an L protein in the virus; a polynucleotide encoding same; and a recombinant vector comprising the polynucleotide.