This is a summary, written by members of the CITF Secretariat, of:

Abubakar H, Valdez C, Lovblum E, Ravindran R, Clarke R, Colwill K, Dayam RM, Gingras A-C, Walmsley S, on behalf of the STOPCOV Research Team. Feasibility and Acceptability of Self-Collected Dried Blood Spots for SARS-CoV-2 Vaccine Response in Community-Dwelling Elderly: A Large Decentralized Prospective Study. J Community Med Public Health. 2023 Apr 26. doi:

The results and/or conclusions contained in the research do not necessarily reflect the views of all CITF members.

A CITF-funded study, published in the Journal of Community Medicine and Public Health, highlighted that using self-collected dried blood spot (DBS) samples to assess the SARS-CoV-2 vaccine responses in older people is feasible and offers acceptable results. Participants in this study were highly engaged, submitting good quality DBS samples within the expected timeframe, and committing to the study for 48 weeks. This study was led by Dr. Sharon Walmsley (University Health Network, University of Toronto).

The SafeTy and Efficacy of Preventative Covid Vaccines (STOP-CoV) study aimed to assess the safety and immune response to COVID-19 vaccines in individuals over 70 years old and compared them to a younger cohort (30-50 years old). It utilized a decentralized approach, where participants self-collected blood samples using a lancet for a single finger-prick and dropping blood on DBS cards for antibody testing.

Key findings:

  • Among the 1,205 eligible participants, 94.3% submitted at least one DBS sample and 68.4% submitted all expected specimens.
  • Overall, 98.1% of specimens were submitted within the expected time window and 93.9% of the submitted samples were adequate for serology testing across the study.
  • Women were more likely to have samples that were adequate for serology testing compared to men after adjusting for time, age, race, and level of education. The proportion of specimens that were adequate for testing increased over time.
  • The older cohort (over 70 years) submitted DBS samples more frequently than the younger cohort over the course of the study’s 48 weeks.

The authors demonstrate the success of using self-collected DBS samples for evaluating the antibody immune response to COVID-19 vaccines in a large cohort of community-dwelling older adults. DBS collection offers a convenient and effective alternative to in-person blood draws.  The DBS method for self-collecting blood samples expands research opportunities for older and vulnerable populations, allowing them to participate in clinical studies and be better represented in public-health related research.

The STOP-CoV study included a total of 1,286 ambulatory adults, including 911 older (70+ years old) and 375 younger (30-50 years) adults who were recruited in Ontario between May and July 2021. DBS samples were requested every three months after the initial vaccine series and three to four weeks after vaccine boosters.