The goal of this study was to investigate COVID-19 risk factors, infection, vaccination and immunity among paramedics in Ontario and British Columbia.
COVID-19 is a global health crisis, but the risks to specific occupational groups such as first responders have not been fully studied. Paramedics are a very high-risk group due to the nature of their work, including treating people who are potentially infected with COVID-19. They often provide care in close proximity and transport patients in confined spaces. Paramedics also routinely provide emergency medical treatments that may increase the risk of transmission, such as CPR for cardiac arrest.
The study recruited 5,000 paramedics in Ontario and British Columbia, who completed surveys and gave blood samples three times over a one-year period.
Blood samples were tested for antibodies to determine the proportion of paramedics who were previously infected with COVID-19 as well as the proportion who have been vaccinated. Antibodies are part of the body’s method of fighting infection, and provide a level of immunity to reinfection. For COVID-19, it is unknown how long the virus’s antibodies remain in the blood, either from previous infection or from vaccination. By measuring antibodies in the blood over time, this study provided information on how long antibodies are produced by the body, and how this may differ between people who had a previous infection compared to those who were vaccinated.
The study also investigated workplace factors that may impact infection, such the risk of administering certain treatments (for example, those that generate aerosols) and the benefit of infection control strategies used by their workplaces. The results will help identify factors that increase or decrease the risk of infection among paramedics, and how their risk compares to other groups such as health care workers and the general population.
This study helped to identify the tasks and procedures that put paramedics most at risk of COVID-19, as well as the protective measures that can reduce their likelihood of infection. This evidence can be used to inform workplace health and safety guidelines to protect paramedics from COVID-19 and future infectious disease outbreaks, as well as seasonal flu.
Preliminary results were presented on October 26, 2021 by Christopher MacDonald, University of Toronto.
This project is supported by funding from the Government of Canada, through the COVID-19 Immunity Task Force.
