Age-Stratified SARS-CoV-2 Infection Fatality Rates in New York City estimated from serological data

ImportanceCOVID-19 has killed hundreds of thousands of people in the US and >1 million globally. Estimating the age-specific infection fatality rate (IFR) of SARS-CoV-2 for different populations is crucial for assessing the fatality of COVID-19 and for appropriately allocating limited vaccine supplies to minimize mortality. ObjectiveTo estimate IFRs for COVID-19 in New York City and compare them to IFRs from other countries. Design, Setting, ParticipantsWe used data from a published serosurvey of 5946 individuals 18 years or older conducted April 19-28, 2020 with time series of COVID-19 confirmed cases and deaths for five age-classes from the New York City Department of Health and Mental Hygiene. We inferred age-specific IFRs using a Bayesian framework that accounted for the distribution of delay between infection and seroconversion and infection and death. Main Outcome and MeasureInfection fatality rate. ResultsWe found that IFRs increased approximately 77-fold with age, with a nearly linear increase on a log scale, from 0.07% (0.055%-0.086%) in 18-44 year olds to 5.4% (4.3%-6.3%) in individuals 75 and older. New York City IFRs were higher for 18-44 year olds and 45-64 year olds (0.58%; 0.45%-0.75%) than Spanish, English, and Swiss populations, but IFRs for 75+ year olds were lower than for English populations and similar to Spanish and Swiss populations. Conclusions and RelevanceThese results suggest that the age-specific fatality of COVID-19 differs among developed countries and raises questions about factors underlying these differences. Key PointsO_ST_ABSQuestionC_ST_ABSHow do age-specific infection fatality rates (IFR) for COVID-19 in the U.S. compare to other populations? FindingsWe estimated age-specific IFRs of SARS-CoV-2 using seroprevalence data and deaths in New York City. IFRs increased more than 75-fold with age, from 0.07% in 18-45 year olds to 5.3% in individuals over 75. IFRs in New York City were higher than IFRs in England, Geneva, France and Spain for individuals younger than 64 years old, but similar for older individuals. MeaningThe age-specific fatality of COVID-19 varies significantly among developed nations for unknown reasons.