CD4+ T follicular helper (TFH) cells are critical to the induction and maintenance of germinal centre reactions and B cell maturation. To better understand how neutralising antibody responses are generated in response to SARS-CoV-2 infection or vaccination, we studied circulating TFH responses to SARS-CoV-2 and ‘common cold’ human coronaviruses (hCoV). By comparing the frequency and phenotypic profile of these cells in uninfected individuals, people recovered from COVID-19 infection, or animal trials of SARS-CoV-2 vaccines, we gain insight into biomarkers of potent neutralising antibody responses and better understand how coronaviruses induce serological responses.