The Preclinical Working Group (PCWG) was charged with standardizing and sharing preclinical evaluation resources and methods and accelerating testing of candidate therapies and vaccines to support entry into clinical trials.

PCWG focused on:

  • Establishing a centralized process and repository for harmonizing and sharing methods and evaluating animal models
  • Extending access to high-throughput screening facilities, especially in biosafety level 3 (BSL-3) labs
  • Increasing access to validated animal models
  • Enhancing comparison of approaches to identify informative assays
  • Generating a process to assess viral variant effects on vaccines and therapeutics
  • 107

    preclinical assets prioritized

  • 4

    guidance documents developed for in vitro and in vivo therapeutic testing

  • 17,000+

    therapeutic activity data points tracked for all variants and subvariants

  • 8.10M

    Developed harmonized protocol for consistent sequence analysis and provided database of consensus mutation calls


TRACE Initiative

The Tracking Resistance and Coronavirus Evolution (TRACE) initiative was established by PCWG in February 2021 to help monitor the global emergence and circulation of SARS-CoV-2 mutations. As the pandemic progressed, the rise of viral variants and their potential to increase the transmission of SARS-CoV-2 and to blunt the effectiveness of vaccines and therapeutics became a critical obstacle to attempts to end the pandemic.

The TRACE Initiative focused on:

  • Monitoring global emergence and circulation of SARS-CoV-2 mutations
  • Cross-referencing initial sequence data against databases of experimentally or clinically phenotyped mutants
  • Characterizing prioritized mutants in vitro/ in vivo through critical-path assays
  • Rapidly sharing activity data with ACTIV and scientific community
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