PRRSV is a costly swine virus that can be controlled through vaccination.
Modified live virus (MLV) vaccines are leading candidates for novel PRRSV vaccines.
The CH-1R vaccine (classical PRRSV) provided some protection against HuN4 infection.
The HuN4-F112 vaccine (highly pathogenic PRRSV) protected against HuN4 infection.
Both vaccines elicited humoral and cellular immune responses.