# SARS-CoV-2 serosurvey across multiple waves of the COVID-19 pandemic in New York City between 2020–2023

## TL;DR

This study tracks how SARS-CoV-2 immunity in New York City changed over time, showing a sharp rise in antibody levels after vaccination.

## Contribution

The study provides detailed seroprevalence data across multiple pandemic waves and vaccine rollouts in a large urban population.

## Key findings

- Seroprevalence exceeded 90% in NYC by July 2022 due to vaccination and natural infection.
- Antibody levels increased gradually during the first two waves and sharply during the third wave.
- The study highlights how immunity evolves as a pandemic transitions to an endemic stage.

## Abstract

Sero-monitoring provides context to the epidemiology of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections and changes in population immunity following vaccine introduction. Here, we describe results of a cross-sectional hospital-based study of anti-spike seroprevalence in New York City (NYC) from February 2020 to July 2022, and a follow-up period from August 2023 to October 2023. Samples from 55,092 individuals, spanning five epidemiological waves were analyzed. Prevalence ratios (PR) were obtained using Poisson regression. Anti-spike antibody levels increased gradually over the first two waves, with a sharp increase during the 3rd wave coinciding with SARS-CoV-2 vaccination in NYC resulting in seroprevalence levels >90% by July 2022. Our data provide insights into the dynamic changes in immunity occurring in a large and diverse metropolitan community faced with a new viral pathogen and reflects the patterns of antibody responses as the pandemic transitions into an endemic stage.

Continued monitoring of population SARS-CoV-2 seroprevalence can reveal infection and vaccination patterns. Here, the authors report data from a prospective hospital-based sero-monitoring study in New York City from 2020–2023, including ~55,000 individuals.