Lionel Shriver is wrong to say that Covid-19 vaccines can’t stop the virus spreading

[Vaccination] reduces death and hospitalisation, but can’t stop Covid from spreading.

The novelist Lionel Shriver misrepresented the evidence about Covid-19 vaccines in a column for the Spectator on 20 November 2021. One of her misleading comments was also included in a widely shared tweet from the Spectator.

Claiming that western governments are “detached from the facts”, Ms Shriver said that rates of Covid infection are higher in vaccinated people in “every age group over 30 in the UK”, and that vaccinated and unvaccinated people “pose a comparable danger to each other”.

But the claims Ms Shriver makes are themselves detached from the facts. The data she refers to from Public Health England (PHE) and the UK Health Security Agency (UKHSA) does not mean that vaccinated people over 30 are more likely to catch Covid-19.

She is also wrong to say that the vaccines “can’t stop Covid from spreading” and that the vaccines “won’t keep you from getting sick or even from making other people sick”. Being vaccinated does not guarantee that someone won’t catch Covid, but overall they do prevent many Covid infections from happening in the first place, and thereby also reduce the number of onward infections in other people.

What did Ms Shriver say?

Referring to one of her previous Spectator columns in which she made similar incorrect claims in August, Ms Shriver said that the Covid vaccines are not effective in preventing people from catching or spreading the virus.

She said: “In August, Public Health England released data which shows that vaccination does not appreciably guard against Covid infection and transmission and protection worked out at around 17 per cent for the over-fifties. As I observed then, this would mean the vaxxed and unvaxxed pose a comparable danger to each other.”

In the next paragraph, she claimed that more recent data continued to support her view, saying: “In every age group over 30 in the UK, the rates of Covid infection per 100,000 are now higher among the vaxxed than the unvaxxed. Indeed, in the cohorts aged between 40 and 79, infection rates among the vaccinated are more than twice as high as among the unvaccinated. PHE’s fruitlessly rechristened body, the UK Health Security Agency, frantically clarifies that the data ‘should not be used to estimate vaccine effectiveness’, a caveat which I include for the sake of accuracy. But the differences in the infection rates are drastic enough for you to draw your own conclusions.”

Ms Shriver is making a common error with this data, which is not clearly presented in the UKHSA report where it appears. We have written about this problem several times before.

Why she is wrong

The most recent UKHSA data for England on the morning of the day when Ms Shriver’s article was tweeted includes a table showing “unadjusted rates of COVID-19 infection” for different age groups. The first column shows the rate “among persons vaccinated with 2 doses”, while the second shows the rate “among persons not vaccinated”.

As Ms Shriver says, the Covid-19 case rate among fully vaccinated people is higher in all the age groups over 30, and more than double the case rate in unvaccinated people aged between 40 to 69. (Although this was not true for people in their 70s, as she claimed.)

However, any comparison that relies on the UKHSA’s unvaccinated case rate is extremely unreliable. Indeed there is reason to believe that the situation in the real world may be the opposite of what these tables show.

According to the Office for Statistics Regulation (OSR), the UKHSA’s unvaccinated population estimates “almost certainly overcount the eligible population, and so lead to large systematic biases in the case rates in the unvaccinated groups”.

We’ve written about misinformation arising from this problem in several recent articles.

The UKHSA report also says on another page: “The case rates in the vaccinated and unvaccinated populations are crude rates that do not take into account underlying statistical biases in the data. There are likely to be systematic differences between vaccinated and unvaccinated populations.”

Ms Shriver does quote one of the UKHSA’s caveats that the data “should not be used to estimate vaccine effectiveness”, but she suggests that the difference in the published case rates is large enough to be confident that vaccinated people are just as likely or more likely to catch Covid.

In reality, as our previous fact checks and the OSR have shown, this entire difference, and more, could be caused by the UKHSA’s uncertain population figures, even before you take account of other potential biases.

What about infectiousness?

Later in the article, Ms Shriver talks about vaccinated and unvaccinated people who catch Covid, and the “comparative contagiousness of each group”.

She quotes the scientific journal Nature saying: “People who become infected with the Delta variant are less likely to pass the virus to their close contacts if they have already had a Covid-19 vaccine than if they haven’t. But that protective effect is relatively small, and dwindles alarmingly at three months after the receipt of the second shot.”

From this she concludes that the vaccines “can’t stop Covid from spreading”, and suggests they “won’t keep you from getting sick or even from making other people sick”.

This isn’t true, because Ms Shriver has failed to take account of the Covid vaccines’ overall role in preventing infections in the first place. Indeed the same UKHSA report from which she took her other data estimates that more than 24 million Covid infections have been prevented by the vaccination campaign in England alone.

You can’t spread it without catching it

The Nature news article that Ms Shriver quotes reports new research into the infectiousness of vaccinated people who nevertheless became infected with Covid—so-called “breakthrough” infections.

The researchers did find that people with breakthrough infections seemed to be less contagious, but that this effect waned over time. However, the authors also say, in the first line of the Introduction: “SARS-CoV-2 vaccines have been shown in randomised controlled trials and real-world population studies to prevent infection”.

This means that many vaccinated people who would have otherwise caught Covid, don’t. And because they don’t catch it, they also don’t pass it on.

As a result, fewer people will be infected—even if a breakthrough case is just as infectious as a case in an unvaccinated person.

In short, it simply isn’t true that the vaccines don’t prevent Covid transmission, or that groups of vaccinated and unvaccinated people are equally likely to infect others.

At the time of writing, we do not yet know how effectively the current vaccines will reduce transmission of the Omicron variant.