There are two types of polio vaccines; the inactivated polio vaccine (IPV) and the live attenuated oral polio vaccine (OPV). The IPV was developed first in 1955, and it successfully eliminated the poliovirus in some countries. To protect the people in those post-eradicated environments the OPV vaccine was generated in 1961. This vaccine reproduces mucosal immunity that decreases the replication and transmittance of the virus. The drawback of the OPV is that since it is an attenuated virus, it can still become virulent and cause poliomyelitis.
Out of the three strains of the poliovirus, two of them have been eliminated. Poliovirus type 3 was eradicated four years after the elimination of poliovirus type 2 in 2015. The largest concentration of the poliovirus type 3 is in Pakistan and Afghanistan. The worldwide eradication of the poliovirus is projected to happen in 2023 as this project began in 1988. If completed, polio would be the second human disease, after smallpox, to become worldwide eradicated.
After reading these two articles, I find it fascinating that we maybe only three years away from the poliovirus becoming completely eradicated worldwide. I do believe is going to take a lot of dedication to achieve this goal as vaccine-derived poliovirus outbreaks also have to be taken into consideration. It was also very shocking to learn that polio could be potentially the second disease to be completely eradicated. Thinking of how advanced technology is now, it is kinda hard to believe that polio would be ONLY be the second disease. As I think that OPV is very helpful, I think it could be also very harmful in countries with poor sanitation. The infected fecal material could be potentially a huge problem.
Vanessa's Mircrobiology Blog 