@AandW
Removing comorbidity factors would probably be a strategy that makes more sense, especially if the vaccine has an unknown efficacy against new variants of concern. General health, fitness, and immuno response is the only course of action that does make sense to universally ensure reduced fatality rates and adverse effects. This is true irrespective of vaccine usage.
@Gideon
With any hypothetical contagious bioweapon you would want to make sure that your own valued population is protected. This could be through supplements to guard against the effects (vaccines, etc.), or by designing it in such a way that the genetic profiles of interest are not critically affected (or entirely unaffected, when possible).
To support such a theory, one would need evidence that not everyone is affected equally. Interestingly, the
Chinese population has a significantly higher percentage of B type blood, and Western countries have a
significantly higher percentage of A type blood. Covid-19 allegedly infects more effectively on A type blood
(
https://www.webmd.com/lung/news/20210303/why-blood-type-may-matter-for-covid-infection). Perhaps it is a coincidence, but perhaps it is the tip of the iceberg of other yet to be discovered characteristic features of the virus that could be targeted at nonresidents of China. In either case we've seen concepts that are consistent with a bioweapon speculation even if there is room for opposing speculation that it isn't a bioweapon. Before the covid story, a scientist in China got into hot water for creating genetically engineered humans with CRISPR technology. It would not be out of character to have other rogue elements that have contributed to unethical activities, up to and including a bioweapon targeted based on genetics. It is also possible that a third party did so to frame China in a bad light. The conclusion isn't clear, but the scenario remains a possibility.