BACKGROUND: In November, 2020, WHO authorised novel oral polio vaccine type 2 (nOPV2) use under Emergency Use Listing in response to outbreaks of circulating vaccine-derived poliovirus type 2 (cVDPV2). Although no concerns were identified in nOPV2 trials, the Global Advisory Committee on Vaccine Safety requested more extensive vaccine safety data during emergency use. The Uganda Ministry of Health declared a cVDPV2 outbreak in 2021 and responded with an nOPV2 campaign in January, 2022. More than 9 million children aged 0-59 months were vaccinated, providing an opportunity to generate robust safety data. METHODS: We monitored the safety of nOPV2 for 42 days post-vaccination using: routine passive surveillance for adverse events following immunisation (AEFI); ongoing acute flaccid paralysis (AFP) surveillance; active, hospital-based surveillance for pre-specified adverse events of special interest (AESI); and active, cohort event monitoring. AFP cases were reviewed by the National Polio Expert Committee. Serious AEFI and all AESI and AFP cases with nOPV2 receipt underwent causality assessment by the National AEFI Committee. FINDINGS: Across surveillance systems, 1128 children vaccinated with nOPV2 experienced one or more AEFI: 43 children identified through passive surveillance, 128 suspected AFP cases, five AESI cases, and 952 children with reported AEFI through cohort event monitoring. Overall, 109 adverse events were considered serious; six (fever, gastroenteritis (n=3), acute disseminated encephalomyelitis, and encephalitis) were determined by the National AEFI Committee to be consistent with causal association to immunisation with nOPV2. No cases of vaccine-associated paralytic poliomyelitis were detected. One death was detected, considered inconsistent with causal association to immunisation with nOPV2, per the National AEFI Committee. INTERPRETATION: No new safety concerns were identified with nOPV2 use in Uganda following a national vaccination campaign, providing valuable data that informed WHO prequalification and product licensure. FUNDING: Centers for Disease Control and Prevention. TRANSLATION: For the French translation of the abstract see Supplementary Materials section.

BACKGROUND: In 2019, WHO recommended dolutegravir (DTG) as a backbone for first- and second-line antiretroviral therapy (ART) regimens for people living with HIV (PLHIV). According to the 2018 Uganda's HIV treatment guidelines, patients with viral non-suppression (≥1,000 copies/mL) should receive intensive adherence counseling (IAC) with repeat viral load (VL) within 6 months. This analysis focused on the prevalence and factors associated with viral suppression following IAC among PLHIV on DTG-based regimens (DBRs) with an initial episode of viral non-suppression (VNS) in Uganda. METHODS: We conducted a retrospective analysis for PLHIV on DBRs with an initial episode of VNS (≥1,000 copies/mL) in Uganda during October 2019-September 2020 who had a follow up VL test result during September 2020-July 2021. Data were abstracted from the Central Public Health Laboratory (CPHL) database, including patient demographics and VL results. Viral non-suppression (VNS) was defined as a VL test result of ≥1,000 copies/mL. We characterized PLHIV on DBRs and used logistic regression models to determine factors associated with VL suppression after an initial episode of VNS. RESULTS: A total of 564 PLHIV on DBRs with an initial episode of VNS were followed up and 43 were excluded due to missing data. Of the 521, 220 (42.2%) were children (<15 years) and 231 (44.3%) were female. Median age was 28 years (interquartile range [IQR]: 12-43 years), and median duration on DBRs was 12 months (IQR: 6-15 months). Overall, 80.8% (421/521) PLHIV had a suppressed viral load at first follow up testing (children = 74.5% [164/220]; adults = 85.4% [257/301]). Children with initial VL results ≥5,000 copies/mL were less likely to achieve viral suppression at follow up testing compared to those with <5,000 copies/mL (AOR: 0.38; 95% CI: 0.20-0.71; p = 0.002). CONCLUSIONS: In a programmatic setting, most adults and children suppressed following an initial episode of VNS on DBRs. High rates of suppression after VNS suggest adherence challenges, rather than drug resistance. Continuation of DBRs should be considered before regimen switch.

HIV-positive children and adolescents face gaps in viral load (VL) testing. To understand trends in pediatric/adolescent VL testing, 7 countries collected data from Laboratory Information Management Systems. Results showed increasing proportion of VL tests done through dried blood spot (DBS) and decreased sample rejection rates for DBS compared with plasma, supporting use of DBS VL when skilled phlebotomy is unavailable.