Unvaccinated 16 times more likely to enter ICU during Delta peak

Unvaccinated people who caught COVID-19 at the height of Sydney’s Delta wave were 16 times more likely to enter intensive care than cases who were double-dosed.

The findings prompted health authorities to warn young people who have not had the vaccine that they are putting themselves at unnecessary risk of severe illness and death.

An analysis of the vaccination status of cases in NSW, conducted by the National Centre for Immunisation Research and Surveillance, found those fully vaccinated were significantly less likely to experience severe disease if infected with the virus.

The report, released on Monday afternoon, found the fully vaccinated made up a tiny fraction of hospitalisations, intensive care admissions and deaths in the first 16 weeks of the Delta wave.

Every person who died from the virus after receiving both doses of vaccine – 47 of the 412 deaths during the reviewed period – was either elderly or had significant comorbidities, such as heart failure or cancer.

The average age of a fully vaccinated person who died was 82. Twenty-nine of the 47 were aged care residents.

When intensive care admissions for COVID-19 peaked in the fortnight ending September 21, the rate of fully vaccinated people who entered intensive care or died from the virus was 0.9 per 100,000 compared to 15.6 per 100,000 in unvaccinated people – a greater than 16-fold difference.

Associate Professor Bette Liu, who co-authored the report, said the data showed NSW’s high vaccination rates were “certainly going to reduce the burden of disease” from COVID-19 circulating.

“The fact that we’ve seen decreasing rates of disease through this outbreak as well, is also an indication of the effect of vaccines,” she said.

While the report found the effect of vaccination was greatest in preventing serious disease and death, people who had received both doses were also less likely to be infected.

Between August 25 and September 7 – the fortnight with the state’s highest number of cases – the infection rate among fully vaccinated people was 49.5 per 100,000 compared to 561 per 100,000 for people who were not vaccinated.

Chief Health Officer Kerry Chant said the report highlighted the significant protection vaccination provided young people who caught COVID-19.

Only 3.7 per cent of people in their 20s and 6.1 per cent of people in their 30s who caught the virus during the 16-week period were fully vaccinated.

“Young people with two doses of a vaccine experienced lower rates of infection and almost no serious disease, while those unvaccinated in this age group were at greater risk of developing COVID-19 and needing hospitalisation,” Dr Chant said.

In the past week, three virus deaths have been reported in people under the age of 40 who had not received a dose. On Monday, one of seven deaths recorded was an otherwise healthy man in his 30s from Sydney’s south-west who had not been vaccinated.

In announcing the death, NSW Health’s Dr Jeremy McAnulty also asked anyone who had not yet booked a vaccine appointment to do so urgently.

NSW hit 93.9 per cent first-dose and 89.9 per cent second-dose coverage of its 16 and over population on Monday, prompting Premier Dominic Perrottet to suggest the state would reach the 90 per cent milestone “today or tomorrow”.

But rates are lower in younger age groups, with 86.7 per cent of people in their 20s, 89.2 per cent of people aged 16 to 19 and 80.1 per cent of children aged 12 to 15 having received at least one shot.

“You would hope those groups are going to continue to increase their vaccination rates,” said Dr Liu, noting young people had not had access to the vaccine for as long.

Hospitalisations for COVID-19 have continued to decline in NSW. On Monday, there were 264 cases in hospital and 48 in intensive care.

On Sunday, Westmead Hospital emergency department deputy director Dr Kavita Varshney said there were two COVID-positive patients in Western Sydney Local Health District and an additional 21 “COVID graduates” – people who are no longer positive but still require hospital treatment.

The situation is a far cry from in September, when Westmead, Liverpool and Campbelltown Hospitals were each home to several COVID-19 wards.

NSW reported 187 new local cases on Monday, a lower figure than in previous days mostly due to declining infections in the state’s north-west.

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