If I were you, I'd double check with RCI. Although the information sent to you by email is consistent with the information on its website, it possibly pre-dates the recent Barbadian update of October 27th. Additionally, it predates the CDC's recent decision to accept AZ-mRNA mixes. With the constant changes, it's very possible that RCI simply hasn't adjusted its protocols yet, or they haven't amended the website. Either way, it's worth checking again, as Barbados does accept mixed AZ-mRNA vaccin