How many Covid-19 patients in ICU are unvaccinated?

Update 11 January 2022: This article correctly summarises the latest data available at the time it was published. Since then, new data has become available, which shows that most Covid patients admitted to ICU in November and December were unvaccinated. We’ve published a new article to explain what we now know about Covid vaccines and patients in ICU.

We’ve seen several reports over the past month claiming “almost all” Covid-19 patients in intensive care units (ICUs) are unvaccinated.

While this used to be true, some of these claims were made when up to date figures were not available. More recent data on ICU admissions, which had already been published by the time Channel 4 News made the claim on 13 December, shows a different picture.

In the three months up to the end of July, 73% of ICU admissions were unvaccinated, but that figure had dropped to 47% in October and 48% in the first half of November.

These figures, which are published by the Intensive Care National Audit and Research Centre (ICNARC), give the best available overview of Covid ICU admissions in England, Wales and Northern Ireland by vaccination status. But they come with some important caveats:

• The ICNARC data is about the number of ICU admissions, not the number of patients in ICU at any given time. It is possible unvaccinated Covid patients in ICU tend to be more severely ill. If so, it is also possible they spend longer in ICU on average, and might therefore make up the majority “in ICU” at a given time—but we don't have clear evidence on this so we can't say for sure.
• The proportions may have changed again since the ICNARC data was published. It only goes up to 15 November, which predates the spread of the Omicron variant, and most of the likely effect of the booster programme.
• None of this means that the vaccines are ineffective. There is overwhelming evidence that vaccination makes people far less likely to get seriously ill with Covid. Because the vast majority of the adult population of the UK has been vaccinated against Covid, if even a small proportion of them get seriously ill, it may be enough to outnumber the severe cases which are more common among the unvaccinated.
• There is some anecdotal evidence (explained below) that many of the vaccinated patients admitted to ICU are immunocompromised. This means that their bodies may not have been able to generate protection in response to the vaccine.

What do we know about Covid in ICU?

Most of the reports we’ve seen talk about the proportion of patients “in” ICU who are unvaccinated (as opposed to the proportion of ICU admissions), but this isn’t data that’s readily available. In fact, we can’t find any centrally collected data on patients in ICU by vaccination status. Data on Covid ICU admissions however has followed a similar path to Covid hospitalisations in general, which we have written about before.

As more people have been vaccinated, and perhaps as vaccine protection has waned slightly, the proportion of admissions who are vaccinated has risen gradually over time.

Until 10 December, ICNARC’s data on ICU admission in England, Wales and Northern Ireland only went up to July. It showed that across May, June and July about 73% of ICU admissions were unvaccinated.

This number was still often being quoted as the latest data at the end of November, even though by then it was potentially out of date. For example, National Medical Director of NHS England Professor Stephen Powis told the Sunday Times: “Data shows that the overwhelming majority of people admitted to intensive care with Covid are not fully vaccinated.” Health campaigner Dr Rachel Clarke wrote (also in the Sunday Times): “Of the Covid patients treated in intensive care in recent months, the majority—nearly 75 per cent according to the latest data—have chosen not to be vaccinated.”

However, when ICNARC updated its figures on 10 December, it showed that things had changed. By October and November, a very slight majority of ICU admissions were vaccinated. (Although this still shows that they were very well protected, because by then a very large majority of adults was vaccinated, including an even larger majority of those who are older and therefore most at risk.)

Of course, the autumn numbers themselves may not fit the picture now, in late December, because they won’t yet show any substantial effect of the booster campaign or the arrival of the Omicron variant.

Anecdotal evidence

As we’ve said, the ICNARC data available at the time of writing only counts admissions. It doesn’t tell us how severely ill these patients were, or how long they stayed in ICU. We therefore can’t use it to say for sure what the vaccination status was of patients “in” ICU at a given time.

Besides the data from ICNARC, there has been local and anecdotal evidence that the most severely ill patients in ICU are unvaccinated.

In an article for the Guardian on 23 November, Professor Andrew Pollard, chair of the Joint Committee on Vaccination and Immunisation, and Professor Brian Angus, a professor of infectious diseases, described the reality of severe Covid infections in hospital. They said: “This ongoing horror, which is taking place in ICUs across Britain, is now largely restricted to unvaccinated people.”

Full Fact asked Professor Pollard what this claim was based on. In response, he told us that he had discussed it with hospitals and ICU teams around the UK. He also told us on 29 November, before the updated ICNARC data appeared, that “the majority of ICU admissions are unvaccinated”.

Professor Pollard now says that what he hears from ICUs at the time of writing is more in line with the latest ICNARC data, showing similar proportions of vaccinated and unvaccinated patients. He has also been told that vaccinated Covid patients in ICU are very often immunocompromised.

News reports in the last week have included claims from hospitals and doctors that a large majority of Covid patients now being seen in ICU are unvaccinated.

For example, on 22 December the Guardian reported that “in some hospitals all new intensive care Covid patients have not had jabs”, quoting a number of hospitals and doctors. We are not able to confirm whether this is typical of ICUs across the country, because we don’t yet have data from ICNARC for December.

What about patients who need the ‘most care and attention’?

Another source of data about severe Covid may also have caused confusion.

Speaking on Sky News on 19 December, the health secretary Sajid Javid said: “If we look at those that are the most ill in hospital, needing the most care and attention, around nine out of 10 of them are unvaccinated.”

Full Fact asked the Department of Health and Social Care what Mr Javid meant. It told us that his nine out of 10 figure did not refer to all patients in ICU, but only those receiving Extra Corporeal Membrane Oxygenation (ECMO) treatment, essentially a type of artificial lung which oxygenates the blood.

Data on this shows that of 154 patients in England who received ECMO due to a Covid infection between the beginning of July and 22 November, 141 were unvaccinated. This amounts to about 92%, and is similar to the figures reported previously in the Sunday Times.

However, patients receiving ECMO treatment are only a very small proportion of those receiving intensive care. ICNARC’s latest report at the time of writing records more than 8,600 ICU admissions with Covid in England, Wales and Northern Ireland between July and October 2021.