Considering the early inequity in global COVID-19 vaccine distribution, we compared the level of population immunity to SARS-CoV-2 with vaccine uptake and refusal between rural and urban Kenya two years after the pandemic onset. A population-based seroprevalence study was conducted in the city of Nairobi (n = 781) and a rural western county (n = 810) between January and February 2022. The overall SARS-CoV-2 seroprevalence was 90.2% (95% CI, 88.6–91.2%), including 96.7% (95% CI, 95.2–97.9%) among urban and 83.6% (95% CI, 80.6–86.0%) among rural populations. A comparison of immunity profiles showed that >50% of the rural population were strongly immunoreactive compared to <20% of the urban population, suggesting more recent infections or vaccinations in the rural population. More than 45% of the vaccine-eligible (≥18 years old) persons had not taken a single dose of the vaccine (hesitancy), including 47.6% and 46.9% of urban and rural participants, respectively. Vaccine refusal was reported in 19.6% of urban and 15.6% of rural participants, attributed to concern about vaccine safety (>75%), inadequate information (26%), and concern about vaccine effectiveness (9%). Less than 2% of vaccine refusers cited religious or cultural beliefs. These findings indicate that despite vaccine inequity, hesitancy, and refusal, herd immunity had been achieved in Kenya and likely other African countries by early 2022, with natural infections likely contributing to most of this immunity. However, vaccine campaigns should be sustained due to the need for repeat boosters associated with waning of SARS-CoV-2 immunity and emergence of immune-evading virus variants.

Objective: To characterize human immunodeficiency virus (HIV)-positive infants among HIV-exposed infants (HEIs) in Nairobi County for public health action. Methods: We conducted a retrospective review of records of HEIs’ HIV polymerase chain reaction (PCR) results in Nairobi County in 2015, excluding confirmatory PCR-positive results. HIV-exposed infant registry data were entered into Microsoft Excel and descriptive and associative statistics were calculated with OpenEpi software. Results: A total of 5802 HEI records were analyzed, with a median age of 4.5 (interquartile range, 8.5) months; 342 (5.9%) tested positive, 51% were female, and 4420 (76.2%) were seen at maternal and child health clinics. Standard highly active antiretroviral therapy intervention was given to 184 (60.3%) of the mothers of exposed infants, and 178 (53%) of the HIV-positive infants received active antiretroviral therapy. A total of 3464 (59.7%) HEIs had PCR done within the first 2 months, and 119 (3.4%) tested positive. The average turnaround time for PCR samples was 28 ± 22 days, and a total of 191 (3.3%) HIV-positive HEIs were exclusively breastfed for the first 6 months of life. Conclusion: The recorded mother-to-child transmission (MTCT) rate of 5.9% in Nairobi County is lower than the 2015 national rate, which suggests the Nairobi prevention of mother-to-child transmission efforts are moderately effective. However, results from this study show that Kenya will struggle to meet the MTCT 2020 target rate of <5%.

Objective: The aim of this study is to estimate the proportion of virologically suppressed People living with HIV on second-line ART and to identify factors associated with virologic suppression. With an increasing population of patients on complex second-line anti retroviral therapy (ART), understanding the factors associated with viral suppression and adherence is critical for ensured longevity of ART. Methods: A retrospective study was conducted of patients on second-line ART in 17 facilities supported by University of Maryland, Baltimore, in Nairobi, Kenya, covering the period beginning October 2016 up to August 2019. Viral suppression was defined as viral load <1000 copies/mL in a test conducted in the last 12 months. Adherence was assessed through self-reports and classified as optimal (good) or suboptimal (inadequate/poor). Associations were presented as adjusted risk ratios with 95% confidence intervals. Statistical significance was considered when p value ⩽0.05. Results: Of 1100 study participants with viral load data, 974 (88.5%) reported optimal adherence while on first-line ART and 1029 (93.5%) reported optimal adherence to second-line ART. Overall, viral load suppression on second-line ART was 90%. Optimal adherence ((adjusted risk ratio) 1.26; 95% confidence interval 1.09–1.46)) and age 35–44 versus 15–24 years ((adjusted risk ratio) 1.06; 95% confidence interval 1.01–1.13)) were associated with viral suppression . Adherence to first-line ART ((adjusted risk ratio) 1.19; 95% confidence interval 1.02–1.40)) was associated with adherence to second-line ART. Conclusion: Viral suppression remains high and adherence was strongly associated with viral suppression, underscoring the need to adequately address the barriers to adherence before switching regimens.

Objective To describe the implementation strategies of the index testing program across Nairobi County in Kenya, assess outcomes along the HIV index testing cascade (acceptance, elicitation ratio, HIV positivity and linkage to treatment), and assess annual changes along the HIV index testing cascade during the first 2 years of implementation. Methods Retrospective analysis of programmatic aggregate data collected from October 2017 to September 2019 after the roll‐out of index testing services in 48 health facilities in Nairobi County. Proportions and ratios were calculated for acceptance, elicitation ratio, testing uptake and HIV positivity. We compared these outcomes between years using a chi‐squared test, Fisher's exact test or Wilcoxon sign test, and we assessed trends using the Mann‐Kendall test. Results Testing among eligible partners increased from 42.4% (1471/3470) to 74.9% (6114/8159) in the general population, and the positivity yield remained high across both years (25.2% in year 1 and 24.1% in year 2). Index testing positivity yield remained significantly higher than other testing modalities (24.3% vs. 1.3%, p < 0.001). The contribution of index testing services to the total number of HIV‐positive individuals identified increased from 7.5% in the first year to 28.6% in the second year (p < 0.001). More men were tested, but the positivity yield was higher among women (30.0%) and those aged 50 years or older (32.4%). Testing eligible partners in key populations (KPs) decreased from 52.4% (183/349) to 40.7% (109/268) (p = 0.674); however, the HIV positivity yield increased from 8.6% to 23.9% (p < 0.001) by the second year of implementation. The HIV positivity yield from index testing remained higher than other testing modalities (14% vs. 0.9%, p < 0.001) for KPs. Conclusion Index testing was well‐accepted and effective in identifying individuals living with HIV in a Kenyan urban setting across both general populations and KPs. Ongoing adaptations to the strategies deployed as part of index testing services helped improve most of the outcomes along the index testing cascade.