You don't get stronger immunity. It's like cold virus. The idea behind cold virus is to not allow your host to develop any immunity. Before host's immune system gets around it, cold virus spreads and kills itself in host. This combined with rapid mutations means that there is no cure for cold. Covid DNA structure is similar and may eventually evolve to adopt same strategy in long term. Killing host is not a good strategy for viruses which is why Ebola was unable to take stronger foothold.