A Recombinant Influenza A/H1N1 Carrying A Short Immunogenic Peptide of MERS-CoV as Bivalent Vaccine in BALB/c Mice

Shehata, Mahmoud M.; Kandeil, Ahmed; Mostafa, Ahmed; Mahmoud, Sara H.; Gomaa, Mokhtar R.; El-Shesheny, Rabeh; Webby, Richard; Kayali, Ghazi; A. Ali, Mohamed

Four groups of mice were intramuscularly injected with inactivated chimeric bivalent 5 + 3, WT 5 + 3, MERS-CoV vaccines, and 1× phosphate buffer saline (PBS). The collected sera of vaccinated groups with inactivated chimeric bivalent 5 + 3 and WT 5 + 3 revealed an increase in antibody titers at two weeks post vaccination (wpv). At week 4, the hemagglutination inhibition (HAI) titers waned after booster vaccination at week 3. The chimeric bivalent 5 + 3 vaccine showed a significant increase in mean HAI titer reaching 6.5 and 8.2 log 2 at weeks 6 and 8, respectively, in comparison with control-PBS group. The inactivated WT 5 + 3 control group showed statistically significant increase in HAI titer at weeks 6 and 8 in comparison with control-PBS and MERS-CoV inactivated groups. These results revealed that the vaccinated mice have a potent immunogenic response against rgH1N1 virus as shown in Figure 3 . Plaque reduction neutralization test (PRNT 50 ) showed a high significant neutralizing titer in inactivated MERS-CoV vaccinated mice 1:160 titer (7.3 log 2 ) at 8 wpv. The chimeric bivalent 5 + 3 vaccinated mice showed a significant increase (p value < 0.001) of nAbs against MERS-CoV reaching to 1:160 (7.3 log 2 ) at week 8 compared to the control group, as demonstrated in Figure 4 . The control-PBS and inactivated WT 5 + 3 groups showed no nAbs in their sera against MERS-CoV throughout the duration of experiment.