Objective:

To determine incidence rates of adverse events of special interest and other clinically significant events following receipt of the Pfizer-BioNTech COVID-19 vaccine in a post-Emergency Use Authorization context, and evaluate for any excessive risk of events post-vaccination.

Approach:

• Study Design: The HERO Together study was a US-based, prospective cohort study conducted from December 2020 to June 2023, initially focusing on healthcare workers and later expanding to include their families and community members to assess vaccine safety in a broader population.

Key Findings:

• The HERO Together study rapidly advanced knowledge in vaccine safety post-EUA by providing real-world data.
• Recruitment strategies effectively reached diverse populations, including healthcare workers and community members.
• Safety data were submitted to the FDA within 7 months of receiving EUA.

Interpretation:

The study's design and recruitment strategies contributed to addressing the urgent need for real-world safety data on the Pfizer-BioNTech COVID-19 vaccine.

Limitations:

• Initial focus on healthcare workers may limit generalizability to the broader population and the findings may not fully represent the experiences of other demographic groups.
• Self-enrollment may introduce selection bias, potentially affecting the reliability of the data.

Conclusion:

The HERO Together study demonstrates innovative methodologies for participant recruitment and safety monitoring in vaccine studies during a public health emergency.