The coronavirus disease 2019 (COVID-19) pandemic, which is caused by the emergence and subsequent global spread of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has caused many countries to experience an acute and overwhelming strain on their healthcare systems. This has led many intensive care units (ICUs) and hospitals around the world to become flooded beyond capacity.
Following the rollout of highly effective vaccines against SARS-CoV-2, it is expected that the incidence of COVID-19 will begin to decline and ultimately allow for a return to a semblance of normalcy. However, public health authorities need a reliable model to forecast future trends in viral transmission and clinical disease.
Study: COVID-19 Vaccination and Healthcare Demand. Image Credit: Kunal Mahto / Shutterstock.com
A new preprint on the medRxiv* server discusses a model that has been developed to predict the effects of relaxing restrictions on social and business interactions, travel, and other non-pharmaceutical interventions (NPIs), along with vaccination coverage, on the number of new COVID-19 cases and the demand on healthcare professionals and facilities.
Healthcare systems have experienced the brunt of the pandemic in many ways. Not only are these the front line of medical management of the disease, but they have had to adapt to different methods of offering routine but unavoidable care to non-COVID-19 patients, including remote consultations.
Meanwhile, many healthcare professionals have also had to take strict precautions against getting infected with SARS-CoV-2 themselves, using personal protective equipment, and being vaccinated early on if in contact with patients.
Many patients have also suffered the postponement of elective but necessary procedures because of the strain on their healthcare providers.
The model discussed in the current model comprises two modules. The first module is epidemiological and makes use of various NPIs both when they are being enforced and after their relaxation, as well as vaccine uptake. The end result is a predicted caseload.
The second module is based on both the output of the first module and estimates healthcare visits, bed occupation rates in hospitals and in ICUs, ICU stay duration, and excess demand for these services and facilities. The current study was carried out in Canada.
Initial strict NPIs reduced infection rates and thus reduced the demand on hospitals and healthcare systems. Vaccination programs in Canada began early in 2021, with an initial goal of getting one dose of the vaccine to as broad of a population as possible in order to quickly provide some immunity to vulnerable populations.
The second dose was then offered earlier than expected. Coincidentally, the second dose was offered at the same time that the SARS-CoV-2 Delta variant emerged in Canada and quickly became the dominant circulating strain. Despite the emergence of this variant, vaccination rates typically slow down after 40-50% coverage, while people tended to relax their personal attitudes of protecting themselves against infection once they were vaccinated with even one dose.
The 50% coverage mark occurred in Canada towards the middle of May 2021, followed by both these phenomena. The current study is aimed at understanding the predicted healthcare burden in quantitative terms.
The researchers found that their model fitted the length of stay in the hospital ward and ICU closely. The model predicts that an excess demand for ICU beds would occur in the fall in some regions of Canada at least, with the decline in vaccine efficacy against newer SARS-CoV-2 variants of concern (VOCs) and with no further significant rise in vaccine uptake.
To free up hospital and ICU beds, patients have to be discharged sooner. However, without better treatments, this cannot be done on a large scale unless NPIs are reintroduced. Unfortunately, this step is extremely disagreeable to the population that is suffering from pandemic fatigue and frustration.
On a brighter note, the model also shows that many regions in Canada, especially those provinces that have the highest population, are unlikely to run out of hospital and ICU beds.
The lesson to be learned is the need to balance NPI relaxation with the healthcare demand. Simply dismissing all earlier NPIs can rapidly lead to a situation where the efficacy of vaccines is limited and enormous loads again fall on the overburdened healthcare system.
In fact, while many provinces are unlikely to experience an excess demand on healthcare services overall during autumn, this could happen with ICU beds.
“It must be noted that Fall resurgence outcomes that do not see excess ICU demand should still be a goal for all Canadians. Increased vaccine uptake should thus be considered, as well as increased uptake and proper practice of personal protective behaviours.”
The model used here can be used for the study of other infectious diseases to express in quantitative terms the healthcare demand in smaller or larger regions.
medRxiv publishes preliminary scientific reports that are not peer-reviewed and, therefore, should not be regarded as conclusive, guide clinical practice/health-related behavior, or treated as established information