These is at a higher dose but gives you a sense:

Although frequently effective, IFNα induces a variety of neuropsychiatric adverse effects, including an acute confusional state that develops rapidly after initiation of high-dose IFNα, a depressive syndrome that develops more slowly over weeks to months of treatment, and manic conditions most often characterised by extreme irritability and agitation, but also occasionally by euphoria. Acute IFNα-induced confusional states are typically characterised by disorientation, lethargy, somnolence, psychomotor removedation, difficulties with speaking and writing, parkinsonism and psychotic symptoms. Strategies for managing delirium should be employed, including treatment of contributing medical conditions, use of either typical or atypical antipsychotic agents and avoidance of medications likely to worsen mental status. Significant depressive symptoms occur in 21–58% of patients receiving IFNα, with symptoms typically manifesting over the first several months of treatment. The most replicated risk factor for developing depression is the presence of mood and anxiety symptoms prior to treatment.

A vaccine trains your immune system to respond, and interferon therapy is throwing the immune system into DEFCON 1

Useful and an achievement for Cuba but still worse than other social interventions

Cases would exhibit some seasonality instead of going to zero for years of new variants

This is not unique to Cuba of course

And of course, even China eventually succumbed to "letting it rip" instead of eradication which was, at one point, actually feasible.