Anti-spike S1 IgA, anti-spike trimeric IgG, and anti-spike RBD IgG response after BNT162b2 COVID-19 mRNA vaccination in healthcare workers

Abstract

Background: Most studies on immune response after coronavirus disease 2019 (COVID-19) vaccination focused on serum IgG antibodies and cell-mediated immunity, discounting the role of anti-SARS-CoV-2 neutralizing IgA antibodies in preventing viral infection. This study was aimed to quantify serum IgG and IgA neutralizing antibodies after mRNA COVID-19 vaccination in baseline SARS-CoV-2 seronegative healthcare workers.
 Methods: The study population consisted of 181 SARS-CoV-2 seronegative healthcare workers (median age 42 years, 59.7% women), receiving two doses of Pfizer COVID-19 vaccine BNT162b2. Serum samples were collected before receiving the first vaccine dose, 21 days (before the second vaccine dose) and 50 days afterwards. We then measured anti-spike trimeric IgG (Liaison XL, DiaSorin), anti-spike receptor binding domain (RBD) IgG (Access 2, Beckman Coulter) and anti-spike S1 subunit IgA (ELISA, Euroimmun). Results were presented as median and interquartile range (IQR).
 Results: Vaccine administration elicited all anti-SARS-CoV-2 antibodies measured. Thirty days after the second vaccine dose, 100% positivization occurred for anti-spike trimeric IgG and anti-spike RBD IgG, whilst 1.7% subjects remained anti-spike S1 IgA negative. The overall increase of antibodies level over baseline after the second vaccine dose was 576.1 (IQR, 360.7-867.8) for anti-spike trimeric IgG, 1426.0 (IQR, 742.0-2698.6) for anti-spike RBD IgG, and 20.2 (IQR, 12.5-32.1) for anti-spike S1 IgA. Significant inverse association was found between age and overall increase of anti-spike trimeric IgG (r=-0.24; p=0.001) and anti-spike S1 IgA (r=-0.16; p=0.028), but not with anti-spike RBD IgG (r=-0.05; p=0.497).
 Conclusions: mRNA COVID-19 vaccination elicits sustained serum levels serum anti-spike trimeric IgG and anti-spike RBD IgG, while also modestly but significantly increasing those of serum anti-spike S1 IgA.

Immunogenicity of BNT162b2 Vaccine in Patients with Inflammatory Bowel Disease on Infliximab Combination Therapy: A Multicenter Prospective Study

“…Another important finding of our study is that while 75-80% of patients on infliximab combination therapy had positive IgG and neutralizing antibody levels, only 40% had positive IgA levels. SARS-CoV-2-circulating antibodies, particularly the IgG class, have been the major contributor to risk reduction of severe COVID-19 after vaccination [24]. IgG antibodies specifically target the spike protein of SARS-CoV-2, its S1 subunit, or its receptor-binding domain (RBD).…”

Humoral immune response to Comirnaty (BNT162b2) SARS-Cov2 mRNA vaccine in Thalassemia Major patients

“…The efficiency of the humoral response to the new vaccines against SARS-CoV-2 is currently a topic of great scientific relevance and represents an important aspect to monitor viral spread and reduce the access in intensive care unit [ 1 , 2 ] Anti-Spike antibodies (anti-S ab) and anti-Nucleocapsid antibodies (anti-N ab) are, at the current time, the best tools to monitor humoral response to SARS-CoV-2 infection [ 3 , 4 ]. Vaccination-induced immunity in comparison to natural infection-induced immunity, provides a strong reason why in vulnerable patients vaccination is needed.…”

Immunogenicity of BNT162b2 Vaccine in Patients with Inflammatory Bowel Disease on Infliximab Combination Therapy: A Multicenter Prospective Study

“…SARS-CoV-2 circulating antibodies, particularly the IgG class, have been the major contributor to risk reduction of severe COVID-19 after vaccination. 24 IgG antibodies specifically target the spike protein of SARS-CoV-2, its S1 subunit or its receptor binding domain (RBD). This diminish or completely halt the binding of the virus with the host receptors.…”