Effective partnership and in-country resource mobilization in Sudan for cVDPV2 outbreak response amid multiple emergencies in 2020-2021.

BACKGROUND: During 2020 and immediately prior to the COVID-19 pandemic, Sudan was experiencing multiple emergencies including violence, seasonal flooding, and vector-borne disease outbreaks. After more than ten years since its last case of wild poliovirus, Sudan declared a circulating vaccine-derived poliovirus type 2 (cVDPV2) outbreak on 9 August 2020. METHODS: cVDPV2 outbreak response data and programme documents of the Federal Ministry of Health and WHO were reviewed. Surveillance data was verified through WHO-recommended procedures for detecting and characterizing polioviruses from stool and sewage samples collected from acute flaccid paralysis (AFP) cases and the environment. RESULTS: This outbreak in Sudan led to a total of 58 confirmed cases of cVDPV2 from 15 of the 18 states. Two nationwide vaccination campaigns were held to increase immunity of children under-five against poliovirus type 2. Funding challenges were overcome by intense additional resource mobilization from in-country sources. The funding gap was bridged from domestic resources (49%) sourced through GPEI partners, and in-country humanitarian funding mechanisms. CONCLUSIONS: During an outbreak response and challenge of funding shortfall, mobilizing in-country resources is possible through coordinated approaches, regular communication with partners, disaggregation of needs, and matching in-kind and financial support to fill gaps. A cVDPV2 outbreak requires a fast, resourced, and quality response to stop virus circulation.

The effect of mass immunisation campaigns and new oral poliovirus vaccines on the incidence of poliomyelitis in Pakistan and Afghanistan, 2001-11: a retrospective analysis.

BACKGROUND: Pakistan and Afghanistan are two of the three remaining countries yet to interrupt wild-type poliovirus transmission. The increasing incidence of poliomyelitis in these countries during 2010-11 led the Executive Board of WHO in January, 2012, to declare polio eradication a "programmatic emergency for global public health". We aimed to establish why incidence is rising in these countries despite programme innovations including the introduction of new vaccines. METHODS: We did a matched case-control analysis based on a database of 46,977 children aged 0-14 years with onset of acute flaccid paralysis between Jan 1, 2001, and Dec 31, 2011. The vaccination history of children with poliomyelitis was compared with that of children with acute flaccid paralysis due to other causes to estimate the clinical effectiveness of oral poliovirus vaccines (OPVs) in Afghanistan and Pakistan by conditional logistic regression. We estimated vaccine coverage and serotype-specific vaccine-induced population immunity in children aged 0-2 years and assessed their association with the incidence of poliomyelitis over time in seven regions of Afghanistan and Pakistan. FINDINGS: Between Jan 1, 2001, and Dec 31, 2011, there were 883 cases of serotype 1 poliomyelitis (710 in Pakistan and 173 in Afghanistan) and 272 cases of poliomyelitis serotype 3 (216 in Pakistan and 56 in Afghanistan). The estimated clinical effectiveness of a dose of trivalent OPV against serotype 1 poliomyelitis was 12·5% (95% CI 5·6-18·8) compared with 34·5% (16·1-48·9) for monovalent OPV (p=0·007) and 23·4% (10·4-34·6) for bivalent OPV (p=0·067). Bivalent OPV was non-inferior compared with monovalent OPV (p=0·21). Vaccination coverage decreased during 2006-11 in the Federally Administered Tribal Areas (FATA), Balochistan, and Khyber Pakhtunkhwa in Pakistan and in southern Afghanistan. Although partially mitigated by the use of more effective vaccines, these decreases in coverage resulted in lower vaccine-induced population immunity to poliovirus serotype 1 in FATA and Balochistan and associated increases in the incidence of poliomyelitis. INTERPRETATION: The effectiveness of bivalent OPV is comparable with monovalent OPV and can therefore be used in eradicating serotype 1 poliomyelitis whilst minimising the risks of serotype 3 outbreaks. However, decreases in vaccination coverage in parts of Pakistan and southern Afghanistan have severely limited the effect of this vaccine. FUNDING: Poliovirus Research subcommittee of WHO, Royal Society, and Medical Research Council.