Waning of SARS-Cov-2 vaccine effectiveness against delta variant in COPD
patients
Abstract
Although, the COVID-19 pandemic is profoundly changing, data on the
effect of vaccination and duration of protection can still be
advantageous, especially for patients with COPD, who are more vulnerable
to respiratory infections. The Hungarian-COVID-19 registry was
retrospectively investigated for vaccine effectiveness (VE) and daily
risk for infection and hospitalization by time since the last
vaccination and vaccine type in adults with COPD diagnosis and an
exact-matched control group during the Delta VOC wave in Hungary. For
the matching sex, age, major comorbidities, vaccination status, and
prior infection was used on August 23, 2021. The study population
included 373 962 cases divided into COPD patients (age: 66.67±12.66) and
a 1:1 matched group (age: 66.73±12.67). In both groups, the female/male
ratio was 52.2:47.7. There was no significant difference between the
groups in daily risks for infection or hospitalization among the
unvaccinated. Regarding vaccinated cases, a faster decline of
effectiveness was noted for hospitalization prevention in the COPD group
regardless of vaccine type. The VE reduction in this group was from
90.1% (mRNA) and 87.8% (other) to 48.8% and 34.1% respectively in
180 days. Based on the time-stratified multivariate Cox analysis of the
vaccinated cases, the hazard ratio was 1.09 (95% CI: 1.05-1.14) for
infection and 1.87 (95% CI: 1.59-2.19) for hospitalization in the COPD
group. Based on our study COPD patients are at higher risk for SARS-Cov2
VE waning and have altogether a higher risk for infection and need for
hospitalization emphasizing suggestion for revaccination measures in
this patient population.