Updated modelling of the prevalence of immunodeficiency-associated long-term vaccine-derived poliovirus (iVDPV) excreters

Abstract

Conditions and evidence continue to evolve related to the prediction of the prevalence of immunodeficiency-associated long-term vaccine-derived poliovirus (iVDPV) excreters, which affect assumptions related to forecasting risks and evaluating potential risk management options. Multiple recent reviews provided information about individual iVDPV excreters, but inconsistencies among the reviews raise some challenges. This analysis revisits the available evidence related to iVDPV excreters and provides updated model estimates that can support future risk management decisions. The results suggest that the prevalence of iVDPV excreters remains highly uncertain and variable, but generally confirms the importance of managing the risks associated with iVDPV excreters throughout the polio endgame in the context of successful cessation of all oral poliovirus vaccine use.

Review of poliovirus modeling performed from 2000 to 2019 to support global polio eradication

“…Table 2 provides an overview of some of the attributes of the model structures and assumptions for the 83 papers that included a poliovirus transmission model [ 4 , 9 , 10 , 14 , 18 – 20 , 22 , 24 – 27 , 33 – 36 , 38 – 41 , 43 , 46 , 47 , 49 – 62 , 64 , 65 , 68 – 71 , 73 – 77 , 81 , 97 – 100 , 129 , 132 – 135 , 147 – 171 ] organized by modeling group. Mathematical models for poliovirus transmission vary considerably in their complexity.…”

“… a All of the following: [ 9 , 14 , 18 – 20 , 22 , 24 – 26 ]. b All of the following: [ 4 , 33 – 36 , 38 – 41 , 43 , 46 , 47 , 49 – 62 , 64 , 65 , 68 , 69 , 71 , 73 – 77 , 81 ]. c All of the following: [ 4 , 9 , 10 , 14 , 18 – 20 , 22 , 24 , 26 , 33 – 36 , 38 – 41 , 43 , 46 , 47 , 49 – 62 , 64 , 65 , 68 , 71 , 73 – 77 , 81 ].…”

Case of Poliomyelitis Caused by Significantly Diverged Derivative of the Poliovirus Type 3 Vaccine Sabin Strain Circulating in the Orphanage

“…As regards iVDPVs, since the year 1961, iVDPV type 2 has been the most prevalent (66% of the cases), followed by types 3 (17%), 1 (12%) and heterotypic mixes (i.e., types 1 and 2, or types 2 and 3-5%) [17]. The registration of cases with prolonged isolation of iVDPV by patients with PID is hard to account for completely due to the irregularity of registration of PID cases in different countries; nevertheless, it is estimated that from 1962 to 2018, 143 VDPV excretors with immunodeficiencies were identified in the world, 32 of which (22.4%) were long-term or chronic excretors of PV3 [18]. Only a few cases of high-level VDPV3 isolations from wastewater are known, the sources of which cannot be determined (the so-called aVDPV), but a high degree of divergence of which from Sabin strain type 3 suggests that their source was a person with immunodeficiency [19,20].…”

“…Although less than 1% of people with PID excrete iVDPV, the potential for iVDPV to enter the human population is considered a serious threat of OPV withdrawal after the global certification for polio eradication [18]. Currently, the ability of iVDPV to infect unvaccinated individuals in the surroundings of the excretor is rare [21]; it has been confirmed for poliovirus type 1 in a specific poorly vaccinated religious group [22] and poliovirus type 2 in a family [23].…”

Stool serology: development of a non-invasive immunological method for the detection of Enterovirus-specific antibodies in Congo gorilla faeces

“…The lack of circulation of wild poliovirus type 1 in Nigeria has been reported since 2016 14,15 . On 25 August 2020, the WHO African region was certified as free of wild poliovirus, leaving only the Eastern Mediterranean Region with endemic circulation of wild poliovirus type 1 in 2 countries (https://www.who.int/wer/2020/wer9541/en/) 6,[11][12][13] . In parallel, another challenge arose with the emergence of vaccine-associated paralytic poliomyelitis 6 .…”