Establishment of a Reference Material in Quality Control for Use in Infectivity and Identity Assays of Recombinant COVID-19 Vaccine, in Accordance with International Standards Organization Guidance.

The COVID-19 pandemic, caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), began in 2019. One of the strategies for pandemic control was mass vaccination. In Brazil, the recombinant COVID-19 vaccine (RCV) was produced on a large scale and offered at no charge to the population. The specifications for quality control analyses of RCV included identity and infectivity determination. To validate the results, a reference material (RM) must be analyzed in parallel with the sample vaccine. This research aimed to establish the RM for use in the identity and infectivity assay for RCV. The candidate RM was analyzed using homogeneity and stability studies. The RM was considered homogeneous for identity (cycle threshold (Ct) ≤ 25.19) and infectivity (average x- was 9.25 log infectious units/mL). The RM was considered adequately stable for identity during the total period in all studies, being stable at -70, 5, and 22.5 °C for 380, 313, and 14 days, respectively (Ct ≤ 21.81). For infectivity, the RM was stable at -70, 5, and 22.5 °C for 380, 97, and three days, respectively. Since the property identity and infectivity values of the RM were established, the new RM could be used in quality control analysis.