RNPC3 and influenza: Mice vaccinated with BPPcysMPEG by the i.n. route showed enhanced protection with almost no influence on the loss of weight after sub-lethal challenge with homologous influenza strain A/Puerto Rico/8/34 (H1N1) and were statistically significant (***, p < 0.001) compared with rNP alone on day 7 (Figure 5C).