First, that's not how monoclonal antibodies are designed to be administered. Second, that's not how they are administered (anywhere). Third, even if they were,

First, that's not how monoclonal antibodies are designed to be administered. Second, that's not how they are administered (anywhere). Third, even if they were, we would call it a vaccine. Why don't we? Because they're many orders of magnitude more expensive than the actual vaccines which are designed to be used prophylactically and do not provide the immunity.