While at FDA, Phil performed vaccine-relevant research and had close involvement with all aspects of the review process, including CMC, preclinical, clinical, and post-marketing. As He left Deputy Director of the Office of Vaccines and Research and Review for about 10 years, Phil played a role in evaluation and licensure of many important vaccines, including those for Covid-19. Since that time, Phil has been a consultant on vaccine regulatory and strategic issues, including as a key advisor to the WHO R&D Blueprint for outbreak preparedness and response. Phil has also been a member of the CEPI Scientific Advisory Committee since its inception.