In order to evaluate when antibody to the SARS-CoV-2 spike protein and neutralizing antibody to spike protein occurs subsequent to vaccination, we tested a 67-year-old healthy male subject at day 0, 6, 10, 14, 21, 35, and 56 who received the two-dose Pfizer BioNTech COVID-19 vaccine at day 0 and 21. IgG antibody avidity to spike protein was first detected at day 14, and neutralizing antibody activity was first detected at day 21. Both IgG and neutralizing antibody to spike protein peaked at day 35 and decreased modestly at day 56. This case report is consistent with the Pfizer BioNTech Phase III clinical trial showing protection is established early post vaccination and continues to increase with the second dose boost.