Delta Variant Doubles Hospitalizations Compared to Alpha

A study from the United Kingdom shows the newer variant led to an increase in severe infections in a mostly unvaccinated population.

A new study from the UK has demonstrated that the risk of emergency care visits or hospital admission was 1.5 times higher for people infected with the Delta variant compared to the Alpha variant.

This very large study of more than 40,000 COVID-19 cases was published in The Lancet Infectious Diseases, and was based on cases confirmed by whole-genome sequencing.

The study was conducted in England between March 29 and May 23, 2021. During the study period, there were 34,656 cases of the Alpha variant (80%) and 8682 cases of the Delta variant (20%). Although the proportion of Delta cases in the study period overall was 20%, it grew to account for around two thirds of new COVID-19 cases in the week starting 17 May 2021 (65%, 3,973/6,090), indicating it had overtaken Alpha to become the dominant variant in England.

In this study, only 1.8% (794/43,338) of COVID-19 cases (with either variant) had received both doses of the vaccine; 74% of cases (32,078/43,338) were unvaccinated, and 24% (10,466/43,338) were partially vaccinated. The authors point out they were not able to provide statistical analysis about how the hospitalization risk differs between vaccinated persons who later develop either Alpha or Delta identified-infections.

“This study confirms previous findings that people infected with Delta are significantly more likely to require hospitalization than those with Alpha, although most cases included in the analysis were unvaccinated,” Gavin Dabrera, MD, one of the study’s lead authors and a consultant epidemiologist at the National Infection Service, Public Health England, said. "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 2 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.”

Earlier this year, The United Kingdom saw the changeover from the Alpha variant to the Delta strain as the predominant virus and it saw quite an uptick in incidence rates. Delta now accounts for 98% COVID-19 cases in the UK, according to the authors.

Here in the United States, the Delta variant has also become the predominant variant and created a surge for breakthrough infection rates, hospitalizations, and deaths. It took only two months for it to establish a foothold from a minority strain to the majority.

Consequences of Delta

The authors suggest the effects of this variant will create a deeper burden on health care.

"Our analysis highlights that in the absence of vaccination, any Delta outbreaks will impose a greater burden on healthcare than an Alpha epidemic,” Dr Anne Presanis, one of the study’s lead authors and Senior Statistician at the MRC Biostatistics Unit, University of Cambridge, said.

There have been reports of health care providers dealing with burnout and PTSD during the pandemic. In addition, there are reports starting to surface that patients will be asked to pay a greater share of their medical bills related to COVID-19.

Presanis reiterates the significance in getting a vaccine and how it can stem people for getting a serious infection. “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.”