The clinical presentation of the ongoing coronavirus disease-19 (COVID-19) pandemic in pregnant women is unique with more asymptomatic infection, higher morbidity when symptomatic, yet without a difference in mortality rate. This is strikingly different from the high mortality observed during the past influenza A pandemics. Though both influenza A virus (IAV) and SARS-CoV-2 are single-stranded RNA viruses, the exquisite vulnerability of pregnant women to influenza A but not COVID-19 remains a mystery. Our objective, therefore, is to determine the mechanisms that predispose pregnant women to severe influenza A but confer protection against SARS-CoV-2 infection by examining the viral entry factors and innate immune response mechanisms in the nasal epithelium of pregnant vs. non-pregnant age-matched women.

Inclusion Criteria:

• Healthy, uncomplicated pregnant subjects in the third trimester ((≥ 28 ≤ 41 weeks' gestation)
• Healthy non-pregnant adult female volunteers between the ages of 18 - 45 years.
• Between 18-45 years old
• Able to provide consent

Exclusion Criteria:

• Patients in labor
• Critically ill patients needing intubation and mechanical ventilation
• Patients with fever or influenza-like illness
• H/o epistaxis or rhinosinusitis
• Nasal polyposis and deviated nasal septum
• Preeclampsia and chronic hypertension
• Use of anti-hypertensives
• Ongoing seasonal allergy
• H/o asthma
• Recent recovery from SARS-CoV-2 or influenza A infection (≤ 4 weeks)
• Recent receipt of either COVID-19 or influenza A vaccine (≤ 4 weeks)
• Use of immunosuppressive medications
• Use of inhaled corticosteroids
• Use of hormonal contraceptives in non-pregnant population
• Allergy to local anesthetic

Only females are eligible for the study.

Pregnant cohort: pregnant women in their third trimester admitted to the hospital for any elective procedure (cesarean delivery, labor induction etc.,)

Non-pregnant cohort: age-matched female volunteers