Linear DNA vaccine prepared by large-scale PCR provides protective immunity against H1N1 influenza virus infection in mice.

•In this study, we developed a large-scale PCR system based on two water baths.•The system produced a large amount of LEC DNA within a few hours at a low cost.•The system was used to obtain an influenza H1N1 HA1 linear DNA vaccine.•The vaccine provided full protection against a viral challenge in a mouse model.