Alpha 1-Antitrypsin

The goal of this study is to learn whether patients who have a genetic mutation in the genes that cause alpha 1 antitrypsin deficiency also have genetic variation in nearby genes that can increase risk for reduced immune function and respiratory infections. To investigate this hypothesis, we will compare immune responses to the 20-valent pneumococcal conjugate vaccine (PCV20, Pfizer) between participants who have one abnormal copy of the SERPINA1 gene and either no COPD exacerbations, vs those with 2 or more COPD exacerbations in the past year.

The goal of this cross-sectional observational study is to estimate the prevalence of lung function impairment as measured by spirometry in a population of Gambian women aged 15 and older. The main question\[s\] it aims to answer are: * What is the prevalence of lung function impairment in Gambian women * What is the prevalence of eosinophilic inflammation in Gambian women Consenting participants will undergo * Spirometry * Fractional exhaled nitric oxide (FENO) testing * α1-antitrypsin testing in patients with lung function impairment as assessed by spirometry