Giorgio Quer et al. –

To the Editor — Vaccines against COVID-19 have been a remarkable public health success. However, as with all vaccines, immunologic response can vary by several orders of magnitude between individuals1. This is important since antibody levels following COVID-19 vaccination have been shown to correlate with the level of protection2. As only a miniscule fraction of the over 5 billion people vaccinated worldwide have undergone blood testing to analyze their immune response, for the majority of people the ultimate measure of their adequacy of immune protection is whether they experience a breakthrough infection and the level of its severity.

Read the full correspondence in Nature Biotechnology.