Antibodies generated by 2 doses of COVID19 mRNA vaccines wane after 6 months—and have poorer neutralizing activity against newer SARSCoV2 variants such as Omicron—shows a ScienceTM study of samples from vaccinated healthcare workers.
Breakthrough SARS-CoV-2 infection boosts nAb responses.
Prior COVID-19 status is a critical parameter for the nAb response to vaccination . Of the 48 HCWs examined, one HCW was positive for antibodies against the SARS-CoV-2 N protein by enzyme-linked immunosorbent assay before vaccination—indicating a SARS-CoV-2 infection prior to vaccination. Four HCWs were anti-N protein positive at their post-first vaccine dose sample, indicating a SARS-CoV-2 infection before or within three weeks following their first vaccine dose.
COVID-19 status was determined by anti-N protein ELISA. Individuals were characterized as anti-N protein positive or anti-N protein negative . ELISA optical density at 450nm are shown for anti-N protein positive and anti-N protein negative HCWs. The dashed line indicates the cut-off of 0.4. Comparisons of NTvalues between anti-N protein positive and anti-N protein negative HCWs are shown for the indicated time points.