Assessing the impacts of COVID-19 vaccination programme’s timing and speed on health benefits, cost-effectiveness, and relative affordability in 27 African countries

Table 1 Vaccine efficacy estimates by vaccine type

Outcome	Vaccine efficacy Base case set \| sensitivity analysis set
	mRNA vaccines		Viral vector vaccines
	1st dose	2nd dose	1st dose	2nd dose
Infection	0.7 \| 0.55	0.85 \| 0.7	0.7 \| 0.55	0.75 \| 0.65
Cases	0.7 \| 0.55	0.9 \| 0.85	0.7 \| 0.55	0.8 \| 0.7
Severe cases	0.85 \| 0.75	0.95 \| 0.9	0.85 \| 0.75	0.9 \| 0.8
Critical cases	0.85 \| 0.73	0.95 \| 0.93	0.85 \| 0.75	0.93 \| 0.78
Deaths	0.85 \| 0.7	0.95 \| 0.95	0.85 \| 0.75	0.95 \| 0.75
Onward transmission	0.47 \| 0.47	0.47 \| 0.47	0.47 \| 0.47	0.47 \| 0.47

In the context of this study, cases are defined as symptomatic infections; severe cases are defined as those that require hospitalisation; critical cases are defined as those that require critical/intensive care units at some point during their hospital stay. This includes cases that eventually proceed to death as their final outcome. These estimates are broadly in line with Barnard et al. [16]. However, Barnard et al. did not provide estimates for efficacy against critical cases [16]. Based on the relative relationship we observed between vaccine efficacy against severe cases (i.e. hospitalisations of at least 2 days long with acute respiratory infection (ARI) code in the primary diagnosis field), critical cases (i.e. hospitalisations of at least 2 days long with ARI code in primary diagnosis field and with either oxygen, ventilation, or intensive care unit use), and deaths reported in the UK Health Security Agency Vaccine Surveillance Report (week 12) [46], we assumed the vaccine efficacy against critical cases to be the average of that against severe cases and that against death. The alternative estimates used in the sensitivity analysis (i.e. the lower limits from their estimated uncertainty ranges) are from the same report [46]

ISSN: 1741-7015

Outcome	Vaccine efficacy Base case set \| sensitivity analysis set
	mRNA vaccines		Viral vector vaccines
	1st dose	2nd dose	1st dose	2nd dose
Infection	0.7 \| 0.55	0.85 \| 0.7	0.7 \| 0.55	0.75 \| 0.65
Cases	0.7 \| 0.55	0.9 \| 0.85	0.7 \| 0.55	0.8 \| 0.7
Severe cases	0.85 \| 0.75	0.95 \| 0.9	0.85 \| 0.75	0.9 \| 0.8
Critical cases	0.85 \| 0.73	0.95 \| 0.93	0.85 \| 0.75	0.93 \| 0.78
Deaths	0.85 \| 0.7	0.95 \| 0.95	0.85 \| 0.75	0.95 \| 0.75
Onward transmission	0.47 \| 0.47	0.47 \| 0.47	0.47 \| 0.47	0.47 \| 0.47