Ivanova 2018.

Methods	Study design: nationwide uncontrolled before‐and‐after study. National AFP surveillance data from 2006 to 2013. Virological testing in WHO‐accredited laboratories of faecal specimens adequately taken and handled. VAPP cases were identified through the acute flaccid paralysis surveillance system, classified by the National Expert Classification Committee Setting: Russian Federation Study dates: 1998 to 2014
Participants	Participants: out of 6643 cases of AFP during the period 1998–2014, 127 cases were VAPP. 82 cases were observed in OPV recipients (rVAPP), whereas 45 cases were observed in non‐vaccinated contacts and classified as ‘contact VAPP’ (cVAPP). Age: the age of the patients varied from 1 month to 5.4 years (8.4 ± 8.1 months old). Children younger than 1 year constituted 74% of the group Sex: boys were dominant (80%) Ninety (70.9%) of the 127 VAPP patients were vaccinated against poliomyelitis. The majority of them (85.6%) had received one dose of OPV, while 10% had received two doses, 3.3% three doses, and 1.1% four doses. The time between OPV administration and the onset of paralysis was 20.9 8.7 days (ranging from 2 to 35 days).
Interventions	Before: exclusive use of OPV scheme OOOO (OPV at 6, 18, 20 months; 14 years) during the period 1998‐2007 After: Sequential scheme IIIOOOO ( IPV at 3, 4.5 months; OPV at 6, 18, 20 months; 14 years) during the period 2008‐2014.
Outcomes	Frequency of the VAPP cases presented as case per million doses of distributed and per million newborns. Criteria for a ‘recipient VAPP’ (rVAPP) case were poliomyelitis symptoms 6–30 days after OPV administration, isolation of the vaccine virus, and residual paralysis 60 days after disease onset. Unvaccinated cases with a similar picture 6 to 60 days after contact with an OPV recipient were classified as ‘contact VAPP’ (cVAPP) cases. Timing of outcome assessment: 10‐year period of tOPV use and a 7‐year period of the use of the sequential IPV–tOPV. Follow‐up: 10‐year period of tOPV use and a 7‐year period of the use of the sequential IPV–tOPV.
Notes	The research was carried out with support from the Federal Budget of the Russian Federation allocated for the implementation of the Polio Eradication Programme in the Russian Federation, the WHO Polio Eradication Programme, the WHO Regional Office for Europe, and a Russian Science Foundation grant (project No.15‐15‐00147). The work of OEI, KLI, and APG were partially supported by Russian academic excellence project “5–100”.
Risk of bias
Bias	Authors' judgement	Support for judgement
ITS/UBA: blinded assessment of primary outcome(s)	Unclear risk	Comment: AFP and virological testing are objective outcomes; however, VAPP requires interpretation.
ITS/UBA: reliable primary outcome measure(s)	Low risk	Comment: national AFP surveillance and virological testing of faecal specimens in WHO‐accredited laboratories adequately taken and handled
UBA: follow‐up of professionals	Low risk	Comment: national AFP surveillance suggests a complete nationwide follow‐up. The follow‐up period was long enough. The AFP surveillance was unchanged from 2006 through to 2014.
UBA: follow‐up of patients	Low risk	Comment: national AFP surveillance suggests a complete nationwide follow‐up. The follow‐up period was long enough. The AFP surveillance was unchanged from 2006 through to 2014.
Conflict of interest	Low risk	Comment: the study was financed from the Russian Federation budget within the framework of the Program for eradication of poliomyelitis in the Russian Federation, WHO Polio eradication initiative, WHO's European Regional Bureau, Russian Foundation for Basic Research (project number 15‐15‐00147).