However, one past trial targeting amyloid with active immunotherapy (AN1792), caused a life-threatening T-cell mediated meningoencephalitis in 6% of patients, leading to trial termination and subsequent caution regarding this approach. [90] Early studies using full-length human tau inoculation in mouse models also provoked inflammation and further tau aggregation, further limiting initial enthusiasm for active immunization [91]. Subsequent vaccination strategies have avoided full-length tau, employing tau fragments, which have not demonstrated off-target immune response, though efficacy has yet to be evaluated.
