Estimating the infection fatality risk of COVID-19 in New York City during the spring 2020 pandemic wave

Background As the COVID-19 pandemic continues to unfold, the infection fatality risk (IFR, i.e. risk of death among all infections including asymptomatic and mild infections) is crucial for gauging the burden of death due to COVID-19 in the coming months or years. Here we estimate the IFR of COVID-19 in New York City (NYC), the first epidemic center in the United States where the IFR remains unclear. Methods We developed a meta-population network model-inference system to estimate underlying SARS-CoV-2 infection rates in NYC during the 2020 spring pandemic wave using case, mortality, and mobility data. Based on these estimates, we further estimated the IFR for all ages overall and for 5 age groups (i.e. <25, 25-44, 45-64, 65-74, and 75+ years) separately, during March 1 – June 6, 2020 (i.e., before NYC began its phased reopening). Findings During March 1 – June 6, 2020, 205,639 laboratory-confirmed COVID-19 cases were diagnosed and 21,447 confirmed and probable COVID-19 deaths occurred among NYC residents. We estimated an overall IFR of 1.39% (95% Credible Interval: 1.04-1.77%) in NYC. Estimated IFR for the two oldest age groups (65-74 and 75+ years) was much higher than the younger age groups and about double estimates reported for elsewhere. In particular, weekly IFR was estimated as high as 6.7% for 65-74 year-olds and 19.1% for 75+ year-olds. Interpretation These results are based on more complete ascertainment of COVID-19-associated deaths in NYC and thus likely more accurately reflect the true, higher burden of death due to COVID-19 than previously reported elsewhere.