Circulating Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Vaccine Antigen Detected in the Plasma of mRNA-1273 Vaccine Recipients.
Level 4 - case-series / case-control
Small prospective longitudinal case series without a comparison group
PubMed 34015087 · doi:10.1093/cid/ciab465
What was done
Longitudinal plasma samples from 13 individuals who received two doses of the mRNA-1273 vaccine were analyzed to track the presence and clearance kinetics of circulating SARS-CoV-2 proteins.
What was found
Eleven of 13 participants had detectable SARS-CoV-2 protein in plasma as early as day 1 after the first injection. The clearance of circulating antigen correlated with the emergence of SARS-CoV-2-specific IgG and IgA antibodies. Quantitative antigen concentrations and exact clearance timelines were not reported in the abstract.
Why it matters
It provides direct evidence that translated viral antigen enters systemic circulation shortly after mRNA vaccination and is cleared as humoral immune responses develop.
Limits
The sample size is extremely small (n = 13), there is no control group, and the abstract lacks quantitative values for antigen concentrations, exact antibody titers, and participant demographic details.
Cited by
- supports In a study of 13 individuals who received the Moderna mRNA vaccine, 11 had detectable S1 subunit and 3 had full spike protein in plasma, but the detection assay exhibited a 25% false positive rate in pre-pandemic samples.