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# Put T-Cell Assessment in Covid-19 Vaccine Trials: Scientists
- URL: https://www.fdaweb.com/put-t-cell-assessment-in-covid-19-vaccine-trials-scientists/
- Published: 2022-04-21T12:00:00.000Z
- Updated: 2026-09-14T17:41:44.000Z
- Author: David McFarland
- Tags: Biologics, #legacy-id-D5151644

A 4/21 letter signed by 69 experts working in academic centers, companies, and non-profit organizations is urging FDA to include a recommendation for T-cell assessment in its guidance to vaccine developers for Covid-19 vaccine trials. The [letter](http://www.fdaweb.com/download.php?file=Letter%5Fto%5FFDA-%5FT-cell%5Fassessment%5Fin%5Fvaccine%5Fstudies%5F4-21-22%5FFINAL.pdf) says that “measuring T-cell responses in addition to antibodies is critical to help better evaluate vaccine efficacy and inform decisions regarding ongoing protection against current and future variants.”

The scientists say the limited study to date of T-cells in SARS-CoV-2 research “is impeding our ability to inform policies related to emerging variants and long-term immune protection after antibody titers have appropriately declined following infection and/or vaccination….. If thorough data had been collected on the broader adaptive immune response, including antibodies and T-cells, since the beginning of the Covid-19 pandemic, we would better understand the risks posed by the emerging variants and could more readily provide swift messaging to counter misinformation and associated vaccine hesitancy.”