The two Infanrix are Hexa (Combined Diphtheria-Tetanus-acellular Pertussis (DTPa), Hepatitis B, Inactivated Poliovirus and Haemophilus influenzae type b Vaccine) and IPV (Combined Diphtheria-Tetanus-acellular Pertussis (DTPa) and Inactivated Poliovirus Vaccine)

so neither incorporate the flu vaccine, the Hexa one which is like IPV but plus Hep B and Hib is not that new either been around at least 16 months as DS has had it.

Maybe on the phone you saw influenzae and thought flu?
It's been around for years, i remember using it 5 years ago.