Revealing the extent of the COVID-19 pandemic in Kenya based on serological and PCR-test data

Policy makers in Africa need robust estimates of the current and future spread of SARS-CoV-2. Data suitable for this purpose are scant. We used national surveillance PCR test, serological survey and mobility data to develop and fit a county-specific transmission model for Kenya. We estimate that the SARS-CoV-2 pandemic peaked before the end of July 2020 in the major urban counties, with 34 - 41% of residents infected, and will peak elsewhere in the country within 2-3 months. Despite this penetration, reported severe cases and deaths are low. Our analysis suggests the COVID-19 disease burden in Kenya may be far less than initially feared. A similar scenario across sub-Saharan Africa would have implications for balancing the consequences of restrictions with those of COVID-19.

The importance of supplementary immunisation activities to prevent measles outbreaks during the COVID-19 pandemic in Kenya

BackgroundThe COVID-19 pandemic has disrupted routine measles immunisation and supplementary immunisation activities (SIAs) in most countries including Kenya. We assessed the risk of measles outbreaks during the pandemic in Kenya as a case study for the African Region. MethodsCombining measles serological data, local contact patterns, and vaccination coverage into a cohort model, we predicted the age-adjusted population immunity in Kenya and estimated the probability of outbreaks when contact-reducing COVID-19 interventions are lifted. We considered various scenarios for reduced measles vaccination coverage from April 2020. FindingsIn February 2020, when a scheduled SIA was postponed, population immunity was close to the herd immunity threshold and the probability of a large outbreak was 22% (0-46). As the COVID-19 restrictions to physical contact are lifted, from December 2020, the probability of a large measles outbreak increased to 31% (8-51), 35% (16-52) and 43% (31-56) assuming a 15%, 50% and 100% reduction in measles vaccination coverage. By December 2021, this risk increases further to 37% (17-54), 44% (29-57) and 57% (48-65) for the same coverage scenarios respectively. However, the increased risk of a measles outbreak following the lifting of restrictions on contact can be overcome by conducting an SIA with [≥] 95% coverage in under-fives. InterpretationWhile contact restrictions sufficient for SAR-CoV-2 control temporarily reduce measles transmissibility and the risk of an outbreak from a measles immunity gap, this risk rises rapidly once physical distancing is relaxed. Implementing delayed SIAs will be critical for prevention of measles outbreaks once contact restrictions are fully lifted in Kenya. FundingThe United Kingdoms Medical Research Council and the Department for International Development