What if a simple shot could be the difference between an overloaded hospital and a system that actually copes when flu and COVID-19 surge? That is exactly what new data is suggesting—yet the way different countries use vaccines paints a much more complicated, and at times controversial, picture.
A new analysis shows that vaccines dramatically cut hospital admissions for both seasonal influenza and COVID-19. But here's where it gets controversial: despite strong evidence that these vaccines help prevent severe disease, many countries still fall short in actually getting people vaccinated—especially those most at risk.
The study highlights striking differences in vaccine uptake from one country to another across the EU/EEA. These gaps suggest that far more could be done to ease pressure on national healthcare systems. In plain terms, if more people took up the vaccines already available, hospitals could see significantly fewer beds filled with flu and COVID-19 patients—especially during peak seasons.
And this is the part most people miss: even though the benefits of vaccination are well documented, influenza vaccination rates in most EU/EEA countries remain below the World Health Organization (WHO) targets for high‑risk groups, such as older adults and people with chronic conditions. At the same time, COVID-19 vaccination coverage is not only below optimal levels in many places, it is actually declining.
To better understand what this means in practice, RespiCompass collaborated with several international modelling teams. Instead of relying on a single model, they combined multiple independent models to simulate different real‑world scenarios. This approach is important because it reduces the dependence on any one set of assumptions and offers a more robust, nuanced picture of what vaccines are likely to achieve.
The results from these joint simulations complement traditional clinical vaccine effectiveness studies. While clinical trials and observational studies tell us how well a vaccine works at the individual level, modelling can estimate what happens at the population level. Together, they provide practical, actionable evidence for national public health agencies, vaccination programme managers, frontline healthcare workers, and science communicators. In other words, the findings help decision‑makers refine and strengthen vaccination strategies for future seasons.
Additional collaborative modelling efforts of this kind can also feed into several key policy areas. For example, they can support cost‑effectiveness analyses by showing how many hospitalisations—and associated healthcare costs—can be avoided. They can assist with resource planning by helping hospitals anticipate demand for beds, staff, and equipment under different vaccination scenarios. And they can guide stronger, more targeted public health communication at both EU/EEA and country level, tailoring messages to groups and regions where uptake is low.
Key findings from the projections
For the period between 5 August 2024 and 1 June 2025, vaccination programmes in EU/EEA countries were projected to:
- Prevent approximately 26–41% of flu‑related hospitalisations among adults aged 65 years and older.
- Reduce COVID-19‑related hospitalisations in the same age group by about 14–20%.
To arrive at these estimates, the modelling teams assumed that vaccine effectiveness against hospitalisation was around 60% for influenza vaccines and 75% for COVID-19 vaccines. These values were chosen based on the most recent and reliable evidence available at the time of the analysis.
However, the exact percentage of hospitalisations avoided varied from country to country. Why? Several factors were at play:
- Different levels of vaccine uptake, especially in older age groups.
- Variations in how easily the viruses spread (transmissibility) in each setting.
- Assumptions about how quickly immunity from vaccination or prior infection might wane over time.
This variability is crucial—and potentially controversial. It implies that countries with lower vaccination rates could be accepting higher levels of preventable hospitalisation as a trade‑off, whether knowingly or not. It also raises the question: are some healthcare systems under strain simply because they are not making full use of the tools already available?
Untapped potential to reduce hospital pressure
Taken together, these findings point to a clear conclusion: there is still substantial untapped potential to reduce pressure on hospitals using both long‑standing measures, such as seasonal flu vaccination, and newer tools like COVID-19 vaccination programmes.
Even modest increases in vaccine uptake can translate into meaningful reductions in hospital admissions. For example, if a country boosts coverage among older adults by just a few percentage points, that could still lead to hundreds or even thousands fewer hospitalisations over a single season. For healthcare workers and policymakers, this could be the difference between manageable winter pressures and a system pushed to its limits.
Here is where opinions may diverge: some might argue that individual choice should always come first, even if it means lower vaccination rates and higher hospital burden. Others might say that, given the evidence, governments and health services should be much more proactive—or even more assertive—in promoting and facilitating vaccination among at‑risk groups.
So what do you think: Are countries doing enough to use vaccines to protect their healthcare systems, or are they leaving preventable hospitalisations on the table? Do you agree that even small increases in vaccine uptake are worth pursuing aggressively, or do you see potential downsides that are often overlooked? Share whether you strongly agree, strongly disagree, or fall somewhere in between—and explain why in the comments.
