CDC said it was "ok" to do so back in January. In Europe they studied mixing mRNA with non-mRNA doses (astra zeneca and pfizer) and that also appeared to work v

CDC said it was "ok" to do so back in January. In Europe they studied mixing mRNA with non-mRNA doses (astra zeneca and pfizer) and that also appeared to work very well: https://www.pbs.org/newshour/health/a-mix-and-match-approach-to-covid-19-vaccines-could-provide-logistical-and-immunological-benefits https://www.pbs.org/newshour/health/a-mix-and-match-approach...