Table 1.

Outline of key caveats when assessing the existing literature on vaccine response in the context of DMARD/biologic therapies

Most literature focuses on influenza or pneumococcal vaccine responses, with a smaller number of studies evaluating tetanus/HBV vaccines. The validity of extrapolating these studies to COVID-19 vaccination using novel (e.g. mRNA) vaccine platforms is uncertain.

Most studies assess only humoral responses to vaccination with limited data on T-cell responses, which may be more important in conferring viral immunity.

The degree to which reduced antibody titres on vaccination correlate with impairment of immunity to COVID-19 is uncertain. T-cell mediated immunity is likely to be important in COVID-19 vaccination based on data to date. However, currently there is no known immune correlate of protection identified.