Tri-valent polio vaccine

[Katana]

What is this?

I did a quick goggle search and could only find information on the OPV or IPV polio vaccine.

Is the trivalent one still used? How does/did that one differ, if it does from the other two?

Thanks for any info.

[amnesiac]

OPV is live & IPV is not. Both use type 1, 2 & 3 polioviruses. IPV (IPOL) is used for all 4 doses in the US.

[Katana]

So the word tri-valent just means that there are types 1,2, and 3 in the vaccine, whether it's OPV or IPV?

And when did they stop using the OPV in the US?