Understanding how respiratory infections affect lung inflammation from ozone exposure

Macrophage Regulation of Ozone-Induced Lung Inflammation

PHASE1 · Duke University · NCT05773001

This study is testing how past respiratory infections affect lung inflammation in people aged 18-55 when they are exposed to ozone.

Quick facts

PhasePHASE1
Study typeInterventional
Enrollment100 (estimated)
Ages18 Years to 55 Years
SexAll
SponsorDuke University (other)
Locations1 site (Durham, North Carolina)
Trial IDNCT05773001 on ClinicalTrials.gov

What this trial studies

This research aims to investigate the impact of prior respiratory infections on lung inflammation susceptibility following ozone exposure. Participants aged 18-55 will undergo a series of tests, including blood draws and breathing tests, over a one-and-a-half-month period. They will be divided into cohorts based on their history of SARS-CoV-2 infection and will be challenged with either filtered air or ozone to evaluate their lung response. The study includes follow-up assessments to monitor participants' health after exposure.

Who should consider this trial

Good fit: Ideal candidates are individuals aged 18-55 with varying histories of SARS-CoV-2 infection.

Not a fit: Patients with no prior respiratory infections or those outside the age range may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could lead to better understanding and management of lung inflammation in individuals with a history of respiratory infections.

How similar studies have performed: Other studies have explored the effects of environmental exposures on lung health, but this specific approach focusing on SARS-CoV-2 infection history is relatively novel.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Individuals between 18-55 yrs. of age (No subject will be excluded from the study on the basis of gender or ethnicity)
* Individuals with knowledge of prior SARS-CoV-2 infection history allowing them to be segregated into one of three cohorts

  * Cohort 1 - No history of SARS-CoV-2 infection (defined as no symptoms consisted with SARS-CoV-2 nor history of a positive SARS-CoV-2 test)
  * Cohort 2 - Documented mild SARS-CoV-2 infection (a positive test, either PCR- or antigen-based) but with mild to no symptoms and no evidence of a lower respiratory tract infection (including no hospitalization, and no oxygen use)
  * Cohort 3 - History of SARS-CoV-2 infection and symptoms/imaging consistent with a lower respiratory tract infection who have recovered, are \>6 months out from their infection, and have normal lung function (spirometry with FVC, FEV1 and FEV1/FVC)

    * There will be no maximal period from SARS-CoV-2 infection for inclusion in the study, the minimal period will be \>6 months out from infection

Exclusion Criteria:

* Individuals with prior SARS-CoV-2 pneumonia who have ongoing respiratory symptoms, are still using supplemental oxygen, or have abnormal lung function
* Individuals with prior SARS-CoV-2 infection that cannot provide documentation of a positive test
* Current smokers of tobacco products including e-cigarettes or those with previous smoking history within the prior 5 years
* Pregnant women and women who are presently lactating.
* Subjects that have received antibiotic administration or an upper respiratory infection within the previous 4 weeks
* College and graduate students or employees who are under direct supervision by any of the investigators in this protocol
* Alcohol or illicit substance abuse
* Chronic cardio/pulmonary respiratory disorders or other medical conditions as determined by the investigator
* Increased airway hyperresponsiveness at baseline as measured by a positive methacholine challenge response (methacholine PC20 FEV1 \< 4 mg/ml)
* Subjects will be requested to refrain from antihistamines, nonsteroidal anti-inflammatory agents, antioxidants (e.g. beta-carotene, selenium, and lutein) and supplemental vitamins (e.g. C and E), for 1 week prior to, and during testing.

Where this trial is running

Durham, North Carolina

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.

View on ClinicalTrials.gov →

Conditions: SARS-CoV-2 Pneumonia

Last reviewed 2026-05-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.