Vaccines 2023

Cases of polio linked to the novel oral polio vaccine type 2 (nOPV2) have been detected in the Democratic Republic of the Congo and Burundi. Since its initial rollout in March 2021, approximately 600 million doses of the vaccine have been administered across 28 countries. These represent the first recorded cases associated with this new vaccine, which was engineered with high expectations that it would not revert to virulence.