Poliovirus and Poliomyelitis Practice Test

Which statement correctly describes VAPP and cVDPV?

VAPP can occur only in the vaccinated person, not contacts.

cVDPV cannot cause outbreaks and remains contained.

VAPP is caused by reversion of Sabin vaccine strains; cVDPV describes outbreaks caused by vaccine-derived strains in under-immunized populations.

VAPP is a vaccine-related paralytic illness caused by reversion of the Sabin vaccine strains in the oral polio vaccine; it can affect the vaccinated person or contacts who are exposed to the attenuated virus. cVDPV, on the other hand, refers to outbreaks caused by vaccine-derived poliovirus strains that have mutated and regained neurovirulence, spreading in under-immunized populations. Therefore, the statement that VAPP results from reversion of Sabin strains and that cVDPV describes outbreaks caused by vaccine-derived strains in under-immunized groups is correct. VAPP can occur in contacts, and cVDPV can and does cause outbreaks in communities with low immunization coverage; these are not infections from wild poliovirus. Moreover, these issues are specific to live attenuated vaccines like OPV, whereas IPV does not cause VAPP or cVDPV.

Both VAPP and cVDPV are forms of wild poliovirus infection.