As I understand it, “serotype” just means that you get immunity from things with the “same serotype”? In which case cow-pox and small-pox were two genotypes of one serotype?
Do we know at this stage that there is only one COV-19 serotype? Do we even know if a COV-19 infection will give good immunity? And do we know that all the existing cases are from one genotype?
Also, flu and corona virus infections sometimes lead to a “cytokine storm,” a result of an extremely complex interaction between the virus and the different individual components of the immune system, both systemic and at the site of the infection. Are we at a stage where we can assign different kinds of immune response for /any/ virus, in /any/ population subgroup?