Abstract Importance Routine case surveillance data for SARS-CoV-2 are incomplete, biased, missing key variables of interest, and may be unreliable for both timely surge detection and understanding the burden of infection.Objective To determine the prevalence of SARS-CoV-2 infection during the Omicron BA.2/BA.2.12.1 surge in relation to official case counts, and to assess the epidemiology of infection and uptake of SARS-CoV-2 antivirals.Design Cross-sectional survey of a representative sample of New York City (NYC) adult residents, conducted May 7-8, 2022.Setting NYC, April 23-May 8, 2022, during which the official SARS-CoV-2 case count was 49,253 and BA.2.12.2 comprised 20% of reported cases.Participants A representative sample of 1,030 NYC adult residents >18 years.Exposure(s) Vulnerability to severe COVID-19, including vaccination/booster status, prior COVID, age, and presence of comorbidities.Main Outcome(s) and Measure(s) Prevalence of SARS-CoV-2 infection during a 14-day period, weighted to represent the NYC adult population. Respondents self-reported on SARS-CoV-2 testing (including at-home rapid antigen tests), testing outcomes, COVID-like symptoms, and contact with confirmed/probable cases. Individuals with SARS-CoV-2 were asked about awareness/use of antiviral medications.Results An estimated 22.1% (95%CI 17.9%-26.2%) of respondents had SARS-CoV-2 infection during the study period, corresponding to ∼1.5 million adults (95%CI 1.3-1.8 million). Prevalence was estimated at 34.9% (95%CI 26.9%-42.8%) among individuals with co-morbidities, 14.9% (95% CI 11.0%-18.8%) among those 65+ years, and 18.9% (95%CI 10.2%-27.5%) among unvaccinated persons. Hybrid protection against severe disease (i.e., from both vaccination and prior infection) was 66.2% (95%CI 55.7%-76.7%) among those with COVID and 46.3% (95%CI 40.2-52.2) among those without. Among individuals with COVID, 55.9% (95%CI 44.9%-67.0%) were not aware of the antiviral nirmatrelvir/ritonavir (Paxlovid™), and 15.1% (95%CI 7.1%-23.1%) reported receiving it.Conclusions and Relevance The true magnitude of NYC’s BA.2/BA.2.12.1 surge was vastly underestimated by routine SARS-CoV-2 surveillance. Until there is more certainty that the impact of future pandemic surges on severe population health outcomes will be diminished, representative surveys are needed for timely surge detection, and to estimate the true burden of infection, hybrid protection, and uptake of time-sensitive treatments.