Question: what is topv and bopv?
Answer: As a result, the type 2 component of oral poliovirus vaccine is slated for global withdrawal through a switch from trivalent oral poliovirus vaccine (tOPV) to bivalent oral poliovirus vaccine (bOPV). tOPV is currently being used or stockpiled in 156 countries, all of which will need to switch from tOPV to bOPV.