Table 2.
cVDPV2 emergences and viruses identified after the switch from trivalent OPV to bivalent OPV, by time-period — worldwide, April 2016 – December 2020.
| Period |
No. cVDPV2 Emergences |
No. Countries Affected |
No. Confirmed AFP Cases | No. Confirmed ES Isolates | No. Confirmed Healthy or Community Contacts | No. Total Viruses | ||
|---|---|---|---|---|---|---|---|---|
| Prevalent | Incident | Prevalent | Incident1 | |||||
| Apr 2016 – Dec 2016 | 3 | 3 | 2 | 2 | 2 | 5 | 2 | 9 |
| Jan 2017 – Dec 2017 | 5 | 4 | 4 | 3 | 96 | 3 | 62 | 161 |
| Jan 2018 – Dec 2018 | 8 | 6 | 7 | 5 | 71 | 81 | 75 | 227 |
| Jan 2019 – Dec 2019 | 44 | 40 | 19 | 14 | 366 | 252 | 176 | 794 |
| Jan 2020 – Dec 2020 | 35 | 14 | 30 | 13 | 1079 | 612 | 286 | 1977 |
| Apr 2016 – Dec 2020 | 672 | 67 | 342 | 342 | 1614 | 953 | 601 | 3168 |
Abbreviations: AFP, Acute Flaccid Paralysis; ES, Environmental Surveillance samples.
1
Includes countries with new emergences, new outbreaks, and new infections by spread from other countries.
2
Sum of first five rows is not equivalent to the last row of the column.