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. 2022 Jan 18;10(2):140.
doi: 10.3390/vaccines10020140.

The Population-Wide Risk-Benefit Profile of Extending the Primary COVID-19 Vaccine Course Compared with an mRNA Booster Dose Program

Tinevimbo Shiri  1 , Marc Evans  2 , Carla A Talarico  3 , Angharad R Morgan  1 , Maaz Mussad  4 , Philip O Buck  3 , Phil McEwan  1 , William David Strain  5   6
Affiliations

The Population-Wide Risk-Benefit Profile of Extending the Primary COVID-19 Vaccine Course Compared with an mRNA Booster Dose Program

Tinevimbo Shiri et al. Vaccines (Basel). .

Abstract

The vaccination program is reducing the burden of COVID-19. However, recently, COVID-19 infections have been increasing across Europe, providing evidence that vaccine efficacy is waning. Consequently, booster doses are required to restore immunity levels. However, the relative risk-benefit ratio of boosters, compared to pursuing a primary course in the unvaccinated population, remains uncertain. In this study, a susceptible-exposed-infectious-recovered (SEIR) transmission model of SARS-CoV-2 was used to investigate the impact of COVID-19 vaccine waning on disease burden, the benefit of a booster vaccine program compared to targeting the unvaccinated population, and the population-wide risk-benefit profile of vaccination. Our data demonstrates that the rate of vaccine efficacy waning has a significant impact on COVID-19 hospitalisations with the greatest effect in populations with lower vaccination coverage. There was greater benefit associated with a booster vaccination strategy compared to targeting the unvaccinated population, once >50% of the population had received their primary vaccination course. The population benefits of vaccination (reduced hospitalisations, long-COVID and deaths) outweighed the risks of myocarditis/pericarditis by an order of magnitude. Vaccination is important in ending the COVID-19 pandemic sooner, and the reduction in hospitalisations, death and long-COVID associated with vaccination significantly outweigh any risks. Despite these obvious benefits some people are vaccine reluctant, and as such remain unvaccinated. However, when most of a population have been vaccinated, a focus on a booster vaccine strategy for this group is likely to offer greater value, than targeting the proportion of the population who choose to remain unvaccinated.

Keywords: COVID-19; boosters; modelling; population risk.

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Conflict of interest statement

T.S., A.R.M. and P.M. are employees of Health Economics and Outcomes Research Ltd., Cardiff, UK. Health Economics and Outcomes Research Ltd. received fees from Moderna in relation to this study. C.A.T. and P.O.B. are employees of Moderna, Inc. and hold Moderna stocks/stock options. M.M. is an employee of Ashfield Healthcare on behalf of Moderna and does not hold stocks/ stock options. M.E. and W.D.S. have no conflicts of interest to declare.

Figures

Figure 1
Figure 1
Model scheme for vaccinating framework.
Figure 2
Figure 2
The impact of different theoretical waning rate on the expected number of daily COVID-19 hospitalisations at three months as a function of infection rates and vaccine coverage.
Figure 2
Figure 2
The impact of different theoretical waning rate on the expected number of daily COVID-19 hospitalisations at three months as a function of infection rates and vaccine coverage.
Figure 3
Figure 3
The number of COVID-19 hospitalisations prevented per 100,000 primary series or booster vaccines (logarithmic scale).
Figure 4
Figure 4
The impact of vaccine coverage and infection rates on the total number of adverse events (myocarditis/pericarditis), hospitalisations, long COVID and deaths after three months by age in vaccinated individuals in the population.
Figure 4
Figure 4
The impact of vaccine coverage and infection rates on the total number of adverse events (myocarditis/pericarditis), hospitalisations, long COVID and deaths after three months by age in vaccinated individuals in the population.
See this image and copyright information in PMC

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References

    1. Polack F.P., Thomas S.J., Kitchin N., Absalon L., Gurtman A., Lockhart S., Perez J.L., Pérez Marc G., Moreira E.D., Zerbini C., et al. Safety and efficacy of the BNT162b2 mRNA Covid-19 vaccine. N. Engl. J. Med. 2020;383:2603–2615. doi: 10.1056/NEJMoa2034577. - DOI - PMC - PubMed
    1. Baden L.R., El Sahly H.M., Essink B., Kotloff K., Frey S., Novak R., Diemert D., Spector S.A., Rouphael N., Creech B., et al. Efficacy and safety of the mRNA-1273 SARS-CoV-2 vaccine. N. Engl. J. Med. 2021;384:403–416. doi: 10.1056/NEJMoa2035389. - DOI - PMC - PubMed
    1. Voysey M., Clemens S.A.C., Madhi S.A., Weckx L.Y., Folegatti P.M., Aley P.K., Angus B., Baillie V.L., Barnabas S.L., Bhorat Q.E., et al. Safety and efficacy of the ChAdOx1 nCoV-19 vaccine (AZD1222) against SARS-CoV-2: An interim analysis of four randomised controlled trials in Brazil, South Africa, and the UK. Lancet. 2021;397:99–111. doi: 10.1016/S0140-6736(20)32661-1. - DOI - PMC - PubMed
    1. Sadoff J., Gray G., Vandebosch A., Cárdenas V., Shukarev G., Grinsztejn B., Goepfert P.A., Truyers C., Fennema H., Spiessens B., et al. Safety and efficacy of single-dose Ad26.COV2.S vaccine against Covid-19. N. Engl. J. Med. 2021;384:2187–2201. doi: 10.1056/NEJMoa2101544. - DOI - PMC - PubMed
    1. Shrotri M., Krutikov M., Palmer T., Giddings R., Azmi B., Subbarao S., Fuller C., Irwin-Singer A., Davies D., Tut G., et al. Vaccine effectiveness of the first dose of ChAdOx1 nCoV-19 and BNT162b2 against SARS-CoV-2 infection in residents of long-term care facilities in England (VIVALDI): A prospective cohort study. Lancet Infect. Dis. 2021;21:1529–1538. doi: 10.1016/S1473-3099(21)00289-9. - DOI - PMC - PubMed

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