(40) An update from MN on the seroprevalence of COVID-19 IgG in our adult population

Background: Since the onset of the COVID-19 global pandemic in 2019, much has been learned about the clinical course and epidemiology of SARS-CoV-2 in the cystic fibrosis (CF) population. Due to the severity of illness seen in this population during the H1N1 pandemic, people with CF (pwCF) were initially thought to be at increased risk of severe disease [1]. However, this community has shown significant resilience without clear evidence for more severe COVID pneumonia [2]. The reasons for this are likely multifactorial including younger age, and long-standing infectious risk mitigation practices such as social-distancing and handwashing.

Methods: Individuals >/= 12 years of age who receive care at the MN CF Center underwent virtual consent and completed a brief, online survey detailing possible exposures, symptoms of COVID-19, and behavioral data (e.g. handwashing, remote work opportunities, social distancing practices). We extracted additional data through the electronic medical record (EMR) to further risk stratify our patient cohort including age, BMI, sex, FEV₁ (forced expiratory volume in 1 second), CFTR modulator use, diabetes. Participants were evaluated for COVID-19 IgG at the time of enrollment (0 months), 6 and 12 months post-enrollment.

Results: Our data include 120 enrollees with an average age of 37 years. 50% of participants are female. Preliminary data show that of those tested, 20.1% had evidence of a natural COVID infection (e.g. IgG+ pre-vaccination or nucleocapsid Ab+). Of these 25, two individuals were hospitalized with COVID pneumonia between December 2020 and October 2021. Induced IgG ranged between 0 to 12 months duration. At this time, 85% of the enrolled participants have been vaccinated against SARS-CoV-2: 67% with Pfizer-BioNTech, 25% with Moderna, and 9% with Johnson & Johnson. This is significantly higher than the vaccination rate of the general population in MN, currently 66%.

Conclusions: As SARS-CoV-2 continually evolves, so too must our understanding of its natural history in pwCF. Our study shows that induced immunity through vaccination results in prolonged (12 months) IgG production in a subset of patients. The increased vaccination rate in the CF population along with infection risk reduction practices have all contributed to reduced disease severity from COVID-19.

Acknowledgements: UMN Medical School COVID-19 Rapid Response Grant Initiative, With One Breath Foundation. We thank our patients and their caregivers for participating in this study.

References: [1] Viviani L, Assael BM, Kerem E; ECFS (A) H1N1 study group. Impact of the A (H1N1) pandemic influenza (season 2009-2010) on patients with cystic fibrosis. J Cyst Fibros. 2011; 10(5):370-6. doi: 10.1016/j.jcf.2011.06.004.



[2] R. Cosgriff, S. Ahern and S.C. Bell et al. A multinational report to characterise SARS-CoV-2 infection in people with cystic fibrosis. Journal of Cystic Fibrosis 19. 2020;355–358. doi: 10.1016/j.jcf.2020.04.012