tl;dr — Immune life history, vaccination, and the dynamics of SARS-CoV-2 over the next 5 years*
This blog is an account of key takeaways I had from the paper by Saad-Roy, C.M et. al.,[1] which was published in Science[2].
The paper looks at various scenarios after the introduction of vaccines and based on different efficacy and longevity. The paper concludes that even with a 100% efficate vaccine it is not possible to achieve Ro < 1 (re-emphasising on the swiss cheese models). All these are modeled with the help of mathematical models of the SIR family. The paper also looks at further effects of second/third waves coming in and the effects of the vaccine under different constraints.
- Further issues of antibody dependent enhancements and intensification of the virus.
- A vaccine is assumed to be available in 1.5 years to the general public in such a way that 0% <= x <= 1% of the population from susceptible and secondary susceptible (secondary → population with vaccinated/natural immunity)
- The paper also tries to model the impacts of vaccine denials under different situations where they have lesser immunity, more immunity and in multiple such brackets of possibilities and report studies. Largely acc to this model, anti-vaxxers might not have a very huge effect on the population getting diseases.
- Caveats — Seasonal trends of other coronavirus is considered here, heterogeneity of the population is ignored(age buckets, chances of exposure, previous conditions), other facts related to logistics are ignored, the rate of vaccination is considered to be similar to what was done for H1N1 vaccinations (~1% from each compartments of susceptible)
This is part of a larger body of papers that I am working on with multiple collaborators from the PathCheck Foundation on testing and vaccine digital management. Please check this blog from Joseph Bae to understand more about the clinical tests of COVID-19 and this blog from Parth Patwa and me to see 2 line summaries of multiple papers on the clinical/testing landscape.
References
[1] Saad-Roy, C. M., Wagner, C. E., Baker, R. E., Morris, S. E., Farrar, J., Graham, A. L., … & Grenfell, B. T. (2020). Immune life history, vaccination, and the dynamics of SARS-CoV-2 over the next 5 years. Science, 370(6518), 811–818.