ABSTRACT
Objectives: To estimate the public health impact of COVID-19 booster vaccination in the UK during Omicron predominance, and to explore the impact in counterfactual scenarios with different booster eligibility or uptake. Method(s): A dynamic transmission model was developed to compare public health outcomes for actual and hypothetical UK Spring and Autumn 2022 booster programs. Outcomes were projected over an extended time horizon from April 2022-April 2023, assuming continued Omicron predominance as in Jan-Mar 2022. Health outcomes included averted cases, hospitalizations, long COVID cases, and deaths. NHS resource use outcomes were averted general ward and intensive care unit bed days and general practitioner visits. Patient productivity loss outcomes considered productive days lost for those in and outside the paid work force. Analyses used publicly available data. Result(s): Model output suggested that actual Spring and Autumn 2022 programs, which offered boosters to older adults and vulnerable populations, would avert approximately 716,000 hospitalizations, 1.9M long COVID cases and 125,000 deaths compared to not offering boosters in Spring and Autumn 2022. In a scenario that broadened eligibility to individuals aged >=5 years, an estimated 1.6M hospitalizations, 8.3M long COVID cases, and 222,000 deaths were averted. A scenario assuming broadened eligibility and increased uptake produced the greatest benefit among scenarios analyzed: 1.6M hospitalizations, 9.2M long COVID cases, and 228,000 deaths averted;and 953M productive days saved. Scenarios offering boosters only to high-risk individuals (aged >=5 years) were also estimated to improve benefit relative to actual programs. High-risk-only programs assuming increased uptake provided about half to two-thirds of the benefit estimated for programs assuming broadened eligibility and increased uptake. Conclusion(s): UK booster vaccination programs were estimated to provide substantial benefit to public health during Omicron predominance. Public health benefits could be maximized by broadening booster eligibility to younger age groups and increasing uptake.Copyright © 2023
ABSTRACT
Many countries have adopted border closures and other jurisdictions (provinces, states, cities, etc.) to control the spread of SARS-CoV-2. Such measures have significantly restricted population movement and have thus led to immense economic and social fallouts. We build a Susceptible-Exposed-Asymptomatic- Infectious (prodromal phase)- Infectious (with symptoms) -Recovered (SEAIR) model with a household structure to investigate the potential of a safe reopening of a border, which can control disease spread but also allow for economic growth. We focus on the Ontario-USA border, considering an opening date of September 21, 2020. In addition to the instantaneous reproduction number, we also define a novel risk indicator by calculating daily new infections’ percentile to inform risk levels promptly. Under ideal conditions, assuming extremely efficient border testing and strict traveler adherence to quarantine policy, the Ontario-USA can be reopened for a maximum daily number of 500 travelers entering Canada. A number exceeding 500 will stem an uncontrollable spread of the virus. Additionally, the current quarantine policy may not be sufficient under specific scenarios;hence testing measures at the border must be extremely efficient. Reopening of the Ontario-USA must consider the potential for disease spread (which can overburden healthcare resources) and economic growth. If a reopening plan is implemented, the local government must limit the number of daily entrances to 500 and enforce a mandatory quarantine, which may need to be stricter than current policy practice. © 2022, Springer Nature Switzerland AG.