  We describe our participation in all five rounds of the TREC 2020 COVID Track
(TREC-COVID). The goal of TREC-COVID is to contribute to the response to the
COVID-19 pandemic by identifying answers to many pressing questions and
building infrastructure to improve search systems [8]. All five rounds of this
Track challenged participants to perform a classic ad-hoc search task on the
new data collection CORD-19. Our solution addressed this challenge by applying
the Continuous Active Learning model (CAL) and its variations. Our results
showed us to be amongst the top scoring manual runs and we remained competitive
within all categories of submissions.
