What would be the most plausible strategy to combine vaccination with natural immunity to maximimize the containment of global pandemics like Covid-19?

For COVID-19 in particular, natural immunity (i.e., from infection) has no place because of the sequelae of infection, including effects on the heart, brain, and other organs.  This is manifested in long COVID and in increased post-infection all-cause mortality.  See, for example, https://www.stroke.org/en/news/2022/03/31/after-covid-19-experts-say-watch-for-these-potential-heart-and-brain-problems.

You should check a multination questionnaire of Deans of Schools of Public Health asking how the pandemic has influenced the future of their curriculum, research and overall objectives of PH for the future...