The Journal of Biological Physics and Chemistry



Volume 21, Number 4, pp. 125-131




Covid-19, vaccination and immunity: an extension of the SIRD model

Jeremy J. Ramsden

Department of Biomedical Research, The University of Buckingham, MK18 1EG, England

The susceptible, infected, recovered and dead (SIRD) model is extended to include vaccination (SIRDV model). The greatly reduced mortality conferred by vaccination tends to prolong the pandemic. The effects of lockdown and differential lockdown (imposed on the unvaccinated) are examined, and those of moral hazard, which encourages vaccinated individuals to behave as if there is no pandemic. The continual emergence of new variants that can evade vaccination makes it ultimately unsustainable.

Keywords: economics, evolution, immune escape, lockdown, moral hazard, SIRDV


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