The model estimates approximately 30 current long-term iVDPV excretors globally and suggests that passive use of a single polio antiviral drug has limited impact without active identification efforts.
What is the global prevalence of long-term iVDPV excretors and what is the potential impact of polio antiviral drugs?
Active identification and treatment with highly effective polio antiviral drugs are necessary to mitigate the risk of live poliovirus reintroduction from immunodeficient excretors after OPV cessation.
BACKGROUND: A small number of individuals with B-cell-related primary immunodeficiency diseases (PIDs) may exhibit long-term (prolonged or chronic) excretion of immunodeficiency-associated vaccine-derived polioviruses (iVDPVs) following infection with oral poliovirus vaccine (OPV). These individuals pose a risk of live poliovirus reintroduction into the population after global wild poliovirus eradication and subsequent OPV cessation. Treatment with polio antiviral drugs may potentially stop excretion in some of these individuals and thus may reduce the future population risk. METHODS: We developed a discrete event simulation model to characterize the global prevalence of long-term iVDPV excretors based on the best available evidence. We explored the impact of different assumptions about the effectiveness of polio antiviral drugs and the fraction of long-term excretors identified and treated. RESULTS: Due to the rarity of long-term iVDPV excretion and limited data on the survival of PID patients in developing countries, uncertainty remains about the current and future prevalence of long-term iVDPV excretors. While the model suggests only approximately 30 current excretors globally and a rapid decrease after OPV cessation, most of these excrete asymptomatically and remain undetected. The possibility that one or more PID patients may continue to excrete iVDPVs for several years after OPV cessation represents a risk for reintroduction of live polioviruses after OPV cessation, particularly for middle-income countries. With the effectiveness of a single polio antiviral drug possibly as low as 40% and no system in place to identify and treat asymptomatic excretors, the impact of passive use of a single polio antiviral drug to treat identified excretors appears limited. Higher drug effectiveness and active efforts to identify long-term excretors will dramatically increase the benefits of polio antiviral drugs. CONCLUSIONS: Efforts to develop a second polio antiviral compound to increase polio antiviral effectiveness and/or to maximize the identification and treatment of affected individuals represent important risk management opportunities for the polio endgame. Better data on the survival of PID patients in developing countries and more longitudinal data on their exposure to and recovery from OPV infections would improve our understanding of the risks associated with iVDPV excretors and the benefits of further investments in polio antiviral drugs.
Tebbens et al. (Thu,) conducted a other in Primary immunodeficiency diseases (PIDs) with long-term vaccine-derived poliovirus excretion. Polio antiviral drugs (PAVDs) vs. Status quo (no PAVDs) was evaluated on Global prevalence of long-term iVDPV excretors. The model estimates approximately 30 current long-term iVDPV excretors globally and suggests that passive use of a single polio antiviral drug has limited impact without active identification efforts.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: