The present invention encompasses canine parvovirus (CPV) vaccines or compositions. The vaccine or composition may be a vaccine or composition containing CPV virus-like particle (VLP), and a preparation method and a use thereof. The CPV VLPs provided by the invention are formed by the CPV VP2 protein. Further, the invention broadly encompasses vaccines comprising combinations of MLV and VLP, which are capable of overcoming MDA against a variety of pathogens, which infect a variety of different species.

A heavy-chain variable region sequence of the nanobody CPV-VHH-H1 has the amino acid sequence set forth in SEQ ID NO: 1; and a gene encoding the nanobody CPV-VHH-H1 has the nucleotide sequence set forth in SEQ ID NO: 2. A nanobody immune library of the CPV is constructed by a phage display technology, a specific anti-CPV nanobody CPV-VHH-H1 is obtained by screening, and it is verified by experiments that the nanobody may specifically bind to the CPV. A new nanobody preparation for use in clinical diagnosis and treatment of the CPV can be developed, and a certain theoretical reserve is provided for applying the nanobody to the field of veterinary biological products.