Larger risk of hospital admission with Delta variant, study suggests

People infected with the Delta variant of coronavirus (Covid-19) carry twice the risk of needing hospital treatment than those with the Alpha strain, a study has suggested.

Researchers looked at more than 43,000 cases in England between March and May. The Lancet, a leading medical journal, has published their findings.

Nearly three-quarters of coronavirus cases in the study were in people who were unvaccinated. Only 1.8% were those who had received both inoculations.

More than double the risk with Delta

The study said around one in 50 patients were admitted to hospital within two weeks of their first positive test. That’s 2.3% of Delta cases and 2.2% of those with the Alpha variant.

Researchers then adjusted these figures to take into account other factors. These included someone’s age, ethnicity and vaccination status. And they determined that the risk of hospital admission more than doubled with the Delta variant compared with Alpha.

Dr Gavin Dabrera is one of the study’s lead authors. He’s a consultant epidemiologist at Public Health England’s National Infection Service. He said:

This study confirms previous findings that people infected with Delta are significantly more likely to require hospitalisation than those with Alpha, although most cases included in the analysis were unvaccinated.

We already know that vaccination offers excellent protection against Delta and as this variant accounts for over 98% of Covid-19 cases in the UK, it is vital that those who have not received two doses of vaccine do so as soon as possible.

It is still important that if you have Covid-19 symptoms, stay home and get a PCR test as soon as possible.

Vaccines work

Moreover, the authors said it’s not possible to draw conclusions about risk among vaccinated patients who go on to develop infections. And studies have shown a link between vaccination and prevention of serious illness from coronavirus.

Dr Anne Presanis, one of the study’s lead authors and senior statistician at Cambridge University’s MRC Biostatistics Unit, said:

Our analysis highlights that in the absence of vaccination, any Delta outbreaks will impose a greater burden on healthcare than an Alpha epidemic.

Getting fully vaccinated is crucial for reducing an individual’s risk of symptomatic infection with Delta in the first place, and, importantly, of reducing a Delta patient’s risk of severe illness and hospital admission.

UK government data shows 88.2% of people aged 16 and over have had at least one dose of a vaccine. And 90.2 million doses have been given overall.