Transmission dynamics of COVID-19 in Ghana and the impact of public health interventions

The study characterized COVID-19 transmission in Ghana in 2020-21 by estimating the time-varying reproduction number (R _t ) and exploring its association with various public health interventions at the national and regional levels. Ghana experienced four pandemic waves with epidemic peaks in July 2020, and January, August and December, 2021. The epidemic peak was the highest nationwide in December 2021 with R _t ≥2. Throughout 2020-21, per-capita cumulative case count by region increased with population size. Mobility data suggested negative correlation between R _t and staying home in the first 90 days of the pandemic. The relaxation of movement restrictions and religious gatherings were not associated with increased R _t in the regions with lower case burdens. R _t decreased from above 1 when schools reopened in January 2021 to below 1 after vaccination rollout in March 2021. Findings indicated most public health interventions were associated with R _t reduction at the national and regional levels.