The Cost-Effectiveness of COVID-19 Vaccination in Australia

COVID-19 first appeared in Australia in early 2020, and since then, it has significantly affected the healthcare system and economy. Fast forward to 2022-2023, Australia faced around 182,800 hospital admissions due to COVID-19. Of these cases, 3.5% required intensive care, 1.3% needed mechanical ventilation, and 3.6% ended in death. Besides the immediate health impacts, Long COVID has been a big concern, with estimates showing that more than 102 million work hours were lost in Australia due to this condition in just one year, translating to a staggering $4.8 billion in lost productivity.

#Antibody Presence and Ongoing Spread

In 2022, a study found that a remarkable 99.6% of adult blood donors in Australia had antibodies against the virus that causes COVID-19, indicating a high level of exposure to the virus. However, despite this, COVID-19 is still spreading. The reasons include changes in the virus itself and weakening immunity from past Vaccinations and infections. To tackle this issue, health authorities recommended booster shots for older adults. Those aged 75 and above should get vaccinated every six months, while those aged 65-74 and certain younger, more vulnerable groups should aim for a shot every year, with a chance for an extra dose if needed.

In late 2024, updated versions of popular vaccines were approved, showing that the fight against COVID-19 was still very much alive.

#Low Vaccination Rates

Despite the grim situation, vaccination rates in Australia have been surprisingly low. As of September 2024, only 19.0% of adults aged 65-74, and 30.5% of those aged 75 and above, had received a vaccination in the last six months. The numbers for younger adults (ages 18-64) were even lower, with only 6.7% getting vaccinated within the last year. To put this into perspective, the vaccination rates for the flu in 2023 were much higher, at about 64% for those aged 65 and older.

#Importance of Cost-Effectiveness Studies

As the vaccination program shifted to become part of the regular immunization schedule, it became essential to assess whether the COVID-19 vaccine was worth the money. A detailed study was conducted to see if a COVID-19 vaccination campaign in the winter and summer of 2024 using an updated vaccine would be cost-effective. The team decided to look at adults aged 18 and over for the winter dose, while those aged 65 and older would be the target for the summer dose.

#The Models at Work

Two separate mathematical models were used to evaluate the costs and benefits of the vaccination campaign. One model focused on tracking how the virus spreads, while the other looked at the costs of treating COVID-19 and its complications. This approach allowed researchers to analyze various factors like the number of expected vaccinations, infections, and Hospitalizations.

#SEIR Model

The SEIR model has two phases. The first phase looked at how the virus spread from January 2020 to February 2024, estimating factors such as natural immunity from infections and the lingering protection from previous vaccinations. The second phase focused on what would happen during the year-long analysis period from March 2024 to February 2025, comparing scenarios with and without the vaccination campaign.

#Vaccine Effectiveness

To determine how effective the vaccines would be, researchers needed real-world data. Recent data from Australia showed different levels of vaccine effectiveness, but the most useful information came from previous vaccine effectiveness against various strains.

#Vaccine Coverage Expectations

The winter campaign targeted all adults aged 18 and above, while the summer dose was primarily for those 65 and older. Predictions of how many people would get vaccinated were based on trends from past vaccination seasons, with total coverage and the number of doses given each month tracked closely.

#Cost-Effectiveness Analysis

The next step was to calculate the costs and benefits of the vaccination versus no vaccination. Researchers wanted to see how much money would be saved from reduced hospitalizations and healthcare costs due to the vaccinations. They looked at various scenarios to understand the financial implications better.

#The Decision Tree

In the decision tree for infections, only sick patients were considered for costs and quality-of-life adjustments. This included potential hospitalizations and issues related to some COVID-19 cases, such as myocarditis and long COVID. The analysis factored in the expected costs associated with each health issue and the long-term impact on quality of life.

#Health Outcomes and Cost Savings

The initial findings showed a decrease in COVID-related hospitalizations and deaths by 23% and 26%, respectively, with the vaccination campaign. This reduction was more pronounced than the overall reduction in COVID-19 infections, which stood at 16%. The campaign also lowered the risk of long-term complications, contributing to a significant decrease in the number of lost quality-adjusted life years (QALYs).

#Cost of the Campaign

The total cost of the vaccination campaign was estimated to be about $1.03 billion, but significant savings of about $511.7 million in treatment costs were also identified. After factoring everything in, the overall cost of the vaccination campaign was approximately $522 million for a population of over 26 million people, leading to an impressive cost-effectiveness ratio.

#Sensitivity Analyses

The researchers also conducted various sensitivity analyses to see how different assumptions would affect the results. It turned out that the cost-effectiveness ratio was influenced heavily by estimates of infection transmissibility and vaccine effectiveness. For example, if the expected rate of infection increased, even by a small amount, the cost-effectiveness improved significantly.

If only older adults were vaccinated, the cost-effectiveness worsened due to a smaller number of people benefiting. Vaccinating a broader age range was found to provide more overall protection to the community. There were many scenarios where if vaccination rates improved, the benefits would increase, making it more cost-effective.

#The Broader Impact

While the primary analysis focused on healthcare costs, looking at things from a broader societal perspective yielded even better results. Including productivity loss from infections showed that vaccination could help save an additional $219 million. This was mainly from preventing acute infections and reducing severe long COVID cases.

The model also outlined the 15 key factors that could influence the cost-effectiveness ratio, ensuring that policymakers understood what areas needed attention.

#Conclusion: A Strong Case for Vaccination

The analysis provides substantial evidence for the effectiveness of a vaccination campaign against COVID-19 in Australia. While the nation has a high level of immunity due to prior vaccinations and infections, the data indicates that further vaccination continues to be valuable. The vaccination campaign could potentially prevent hundreds of thousands of infections, thousands of hospitalizations, and many deaths, all while being economical.

Although challenges remain, particularly with the emergence of new variants, the data supports the idea that a comprehensive vaccination approach can lessen both the clinical and economic impacts of COVID-19.

In short, the math shows that getting vaccinated could save us from not just a bad cold, but also from the financial headache of COVID-19 treatment. And while we might not have discovered the secret to eternal life, at least we can extend the quality of life for many by rolling up our sleeves! So, here’s hoping more people get the message and take their shots before the next wave of sneezes, coughs, and hospital visits come knocking.