BibTex format
@article{Majeed:2021:10.1136/bmj.n1976,
author = {Majeed, A},
doi = {10.1136/bmj.n1976},
journal = {BMJ: British Medical Journal},
pages = {1--1},
title = {Longitudinal data on covid-19 immunity could be collected from medical records},
url = {http://dx.doi.org/10.1136/bmj.n1976},
volume = {374},
year = {2021}
}