IgG genetic differences in people with alpha-1 antitrypsin deficiency

Genetic Variation in IgG as a Mechanism for Immune Deficiency and Exacerbations in AATD

PHASE4 · University of Alabama at Birmingham · NCT07135427

This study will test whether adults who carry one SERPINA1 Z mutation and have frequent COPD exacerbations make weaker antibody responses to the 20-valent pneumococcal vaccine than similar people without recent exacerbations.

Quick facts

PhasePHASE4
Study typeInterventional
Enrollment30 (estimated)
Ages19 Years and up
SexAll
SponsorUniversity of Alabama at Birmingham (other)
Locations1 site (Birmingham, Alabama)
Trial IDNCT07135427 on ClinicalTrials.gov

What this trial studies

This Phase 4 interventional study compares immune responses to the 20-valent pneumococcal conjugate vaccine (PCV20, Pfizer) in adults heterozygous for the SERPINA1 Z allele who either had no COPD exacerbations or had two or more exacerbations in the prior year. Participants who received a pneumococcal conjugate vaccine within the past five years are excluded, although prior receipt of the pneumococcal polysaccharide vaccine is permitted. The study team will measure antibody responses after vaccination and perform genetic analyses of IgG-related loci near SERPINA1 to identify variation linked to reduced immune function and respiratory infection risk. Findings will be compared between the two exacerbation groups to determine whether genetic variation correlates with vaccine response or clinical susceptibility.

Who should consider this trial

Good fit: Adults heterozygous for the SERPINA1 Z allele who have either no COPD exacerbations or two or more exacerbations in the past year and who have not received a pneumococcal conjugate vaccine within five years are the intended participants.

Not a fit: People without the SERPINA1 Z mutation, those recently vaccinated with a pneumococcal conjugate vaccine within five years, or those with known severe allergies to the vaccine are unlikely to benefit from participation.

Why it matters

Potential benefit: If a link is found, this could identify people who need different vaccine strategies or closer monitoring to prevent respiratory infections.

How similar studies have performed: Prior research has linked AATD genetics to infection risk and vaccine responses, but using PCV20 responses to detect IgG gene variation in SERPINA1 heterozygotes is a relatively novel approach.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Adults who are heterozygous for a SERPINA1 Z allele
* Have either had no COPD exacerbations or 2 or more exacerbations in the previous year
* Has not received a pneumococcal conjugate vaccine within the past 5 years, or has only received the pneumococcal polysaccharide vaccine in the past

Exclusion Criteria:

* Received a pneumococcal conjugate vaccine within the past 5 years
* Known allergy, severe adverse reaction, or other sensitivity to pneumococcal conjugate vaccines

Where this trial is running

Birmingham, Alabama

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: Alpha 1-Antitrypsin, COPD, Antibody Deficiency

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.