Cold bags for vaccine?

Hello all,

I hope to find an answer to my question here. I am leaving tomorrow on a trip,
and I need to take with me vaccine (Hepatitis B 2 last shots) but the
recommended storage temperature is 2-8 C.

The flight will take around 24 hours one way. I have many connections. Could
you please tell me how I can keep the drug in that temperature during the
trip? As soon as I arrive I will put it in a fridge, but while flying I need
to keep it in a colder temperature....

Are there any ?cold bags? I can use? Please help!!

Thanks,
Julie
.