Project 466523

The COVID-19 pandemic is caused by SARS-CoV-2, which has infected over 261 million people and caused over 5 million deaths worldwide. Pregnant women have been especially affected by COVID-19, leading to worse pregnancy outcomes, such as more frequent hospitalizations and increased pre-term births. This may be associated with changes in the maternal immune system during pregnancy.Upon infection, our immune system produces antibodies, which specifically recognize the infecting virus. There are at least 4 common cold coronaviruses that are closely related to SARS-CoV-2 ; these are called Human Coronaviruses (HCoV). Because these HCoV are closely related to SARS-CoV-2, antibodies that were previously made by our immune systems against them can alter our immune response to SARS-CoV-2. Recent studies have shown that patients with severe COVID-19 have higher levels of HCoV antibodies in their blood. At the same time, people who recently had the common cold were found to have milder COVID-19. Our study aims to fill this gap in knowledge to understand what role these HCoV antibodies play during a SARS-CoV-2 infection ; if they can contribute to protection from severe disease, or worsen the outcomes of COVID-19 in pregnancy.We believe that antibodies against HCoV can modify the antibody levels generated in response to a SARS-CoV-2 infection; this can then affect COVID-19 severity and outcomes during pregnancy. We will investigate how the levels of antibodies against SARS-CoV-2 and HCoV are associated with pre-existing maternal conditions and pregnancy outcomes. Our findings will provide guidance on clinical care for COVID-19 affected pregnancies and inform vaccination guidelines for pregnant women.