According to the above arguments, we consider it unlikely that a conventional vaccine based on young adult responses will be highly effective in COVID prophylaxis for older adults, but should be rigorously applied to everyone else to achieve herd immunity that will indirectly protect the elderly. The ability to prevent infection by adoptive immunotherapy remains a possibility, albeit logistically and financially challenging. Pharmacological prevention of infection by other means, for example, by blocking the interactions between viral proteins and host cell molecules acting as receptors may be useful. Finally, various ways to improve the general immune functions in the older population should be considered and developed to strengthen the immune response to infection and vaccine in general. These approaches could include interventions at the level of hematopoiesis to correct the skewing of output towards dysfunctional myeloid cells responsible for acute inflammatory responses in the lung, normalisation of T cell progenitor output and reconstitution of the thymus for correct selection of T cells, especially regulatory T cells to keep inflammation in check, reconstitution of antigen presentation function in the lymph nodes and re-alignment of T-B cell interactions and functionality. In the meantime, the major benefit of vaccination will be seen at the population level in younger people. Once herd immunity is established, the well-known effect of diluting out new hosts for acute viruses should result in the virus disappearing, with the proviso that protective immunity is retained for long enough (this is not yet established) and reinfection is not introduced from a location where new hosts were still available. And with the linked proviso that the virus does not mutate into a form against which immune memory is not present.