Longitudinal cohort study of primary healthcare workers reveals long-lasting SARS-CoV-2 humoral immunity in the absence of vaccination UniBarcelona BioMedCentral SARSCoV2 COVID19 Coronavirus HealthcareWorkers HumoralImmunity
By Dr. Chinta SidharthanOct 24 2022Reviewed by Aimee Molineux In a recent study published in BMC Medicine, researchers performed a longitudinal cohort study to assess the levels of immunoglobulins M , G , and A against the spike and nucleocapsid proteins of severe acute respiratory syndrome coronavirus 2 in 247 primary health care workers in Barcelona, Spain across 616 days from the onset of the coronavirus disease 2019 pandemic.
Waning humoral immunity and the emergence of immune-evading SARS-CoV-2 variants can increase the susceptibility to reinfections. Furthermore, many studies have found strong correlations between comorbidities and the severity of COVID-19, but the effect of comorbidities on the antibody levels from previous infections has not been investigated.
The effect of a wide range of comorbidities such as diabetes mellitus, chronic obstructive pulmonary disease, cardiovascular diseases, autoimmune diseases, cancer, and many more on the antibody responses to SARS-CoV-2 infections was analyzed. Results The results reported that while a significant but gradual decline was noted in antibody levels over time, the seropositivity against the five SARS-CoV-2 proteins cumulatively remained above 90% during the study period. The seropositivity in the unvaccinated subset was 95.65%. The highest seropositivity was for IgA and IgG , with mainly anti-spike protein and anti-RBD responses for IgG and anti-spike responses for IgA and lower for IgM , which were primarily anti-RBD responses.