(93) Estimation of COVID-19 Vaccination Uptake by Brand to Inform Global Impact Measurement

Publication Number: 767

Background: Multiple vaccines were developed and deployed to populations globally in response to the COVID-19 pandemic. These vaccines have different dosing regimens, variable effectiveness, and wane at different rates. Brand-specific data can help us to better characterize the immune landscape due to vaccination. However, the vast majority of reported vaccine uptake data is brand agnostic and existing sources suffer from a high degree of missingness for many locations and time periods.

Objectives: We sought to produce a complete time series of vaccine uptake by location, day, and brand. These estimates may serve as inputs into subsequent efforts to ascertain the global impact of COVID-19 vaccines in terms of infections, hospitalizations, and deaths averted.

Methods: Since the start of the COVID-19 pandemic, the Institute for Health Metrics and Evaluation (IHME) at the University of Washington has been collating and tracking reported COVID-19 outcomes, projecting the trajectory of the pandemic, and quantifying its toll. Building on this work, we produced estimates of COVID-19 vaccine coverage globally by location, by day since December 1, 2020, and by brand. We included 10 brands in our analysis (CanSinoBio, CoronaVac, Covaxin, Johnson & Johnson, Moderna, Novavax, Oxford-AstraZeneca, Pfizer-BioNTech, Sinopharm, and Sputnik V), as well as a residual “other” category. We rely on observed brand-specific vaccine uptake data rather than estimated uptake when available. Absent brand-specific uptake data for many locations in the world, we developed a stepwise estimation approach to quantify vaccine uptake as a function of predicted vaccine supply, distribution, and hesitancy. We estimate newly available doses by brand based on purchase agreements, model distribution as a function of location-specific infrastructure and brand-specific abundance, and assume 10% spoilage and 10% drop-out for two-dose series.

Results: Between December 1, 2020 and December 31, 2021, we estimate that 8 billion doses of vaccine were administered globally, excluding boosters. This includes 2.6 billion, 1.3 billion, and 1.2 billion doses of Sinopharm, Oxford-AstraZeneca, and Pfizer-BioNTech vaccines, respectively. We estimate that 3.9 billion individuals were fully vaccinated during that period: 571 million with a single dose of Johnson & Johnson; the remaining with two-dose regimens. As of December 31, 2021, we estimate that 806 million had received only a single dose of a two-dose regimen. Of these, we expect only 395 million will complete their series.

Conclusions: These estimates of vaccine uptake by brand can be used to inform subsequent analyses of global impact as well as to identify the size of partially-vaccinated populations globally.