Lockdowns may reduce the peak of transmission and recovery rates but not the number of critical cases or overall mortality.
Lastly, government actions such as border closures, full lockdowns, and a high rate of COVID-19 testing were not associated with statistically significant reductions in the number of critical cases or overall mortality.
…full lockdowns and early border closures may lessen the peak of transmission, and thus prevent health system overcapacity, which would facilitate increased recovery rates.
https://www.thelancet.com/journals/eclinm/article/PIIS2589-5370(20)30208-X/fulltext