The newly identified coronavirus SARS-CoV-2 is responsible for the worldwide pandemic COVID-19. Considerable efforts have been made for the development of effective vaccine strategies against COVID-19. The SARS-CoV-2 spike protein has been assigned as major antigen candidate for the development of COVID-19 vaccines. The COVID-19 mRNA BNT162b2 vaccine (comirnaty, Pfizer/BioNTech) is a lipid nanoparticle-encapsulated mRNA encoding a full-length and prefusion-stabilized SARS-CoV-2 spike protein. In the present study, synthetic peptide-based ELISA assays were performed to identify linear B cell epitopes that contribute to elicitation of antibody response in vaccinated individuals with comirnaty. The synthetic S2P6 peptide containing the spike residues 1138/1169 and to a lesser extent, the synthetic S1P4 peptide containing the spike residues 616/644 were recognized by the immune sera from comirnaty recipients but not COVID-19 recovered patients. The S2P6 peptide has been identified as immunogenic peptide in adult BALB/c mice that received protein-peptide conjugates in a prime-boost schedule. Based on our data, we propose that the synthetic S2P6 peptide and to a lesser extent the synthetic S1P4 peptide, would be of interest to measure the dynamic of antibody response to comirnaty vaccine. The synthetic S2P6 peptide is a SARS-CoV-2 spike peptide candidate for the development of peptide-based vaccines against COVID-19.