Lessons Learned From the Implementation of a Participant-Collected, Mail-Based SARS-CoV-2 Serological Survey in Massachusetts, USA

The rapid spread of SARS-CoV-2 is largely driven by pre-symptomatic or mildly symptomatic individuals who transmit the virus. Serological tests to identify antibodies against SARS-CoV-2 are an important tool to characterize subclinical infection exposure, which is critical in determining transmission trajectories and consequent population immunity. During the summer of 2020, a mail-based serological survey with self-collected dried blood spot (DBS) samples was implemented among university affiliates and their household members in Massachusetts, USA. Described here are some of the challenges faced and novel procedures used during the implementation of this study to assess the prevalence of SARS-CoV-2 antibodies amid the global pandemic. Important challenges included remote and contact-minimized participant recruitment, limited availability of commodities and laboratory capacity, a potentially biased sample population, and policy changes impacting the distribution of clinical results to study participants. Methods used to surmount these challenges and lessons learned are presented to inform similar studies. Key lessons relate to the acceptability and feasibility of DBS sampling, supply requirements, the logistics of packing and shipping packages, data linkages to enrolled household members, and the utility of having an on-call nurse available for participant concerns during sample collection. Future studies might consider additional recruitment techniques such as conducting studies during academic semesters when recruiting in a university setting, partnerships with supply and shipping specialists, and using a stratified sampling approach to minimize potential biases in recruitment. This study design highlights the feasibility and acceptability of self-collected bio-samples and has broad applicability for other serological surveys for a range of pathogens.