Unvaccinated are 16 times more likely to end up in the ICU or die from COVID-19

People who are fully vaccinated are 16 times less likely to end up in intensive care or to die from Covid-19 than those who aren’t immunized, an Australian government study found.

Nearly 16 out of 100,000 people who had yet to receive a Covid vaccine landed in intensive care or died after contracting the virus, compared to fewer than one in every 100,000 who were fully vaccinated, according to data compiled by health authorities in New South Wales, Australia’s most populous state. The country has rolled out highly potent mRNA vaccines co-developed by Pfizer Inc. and BioNTech SE, a similar one from Moderna Inc., and a viral vector shot from the University of Oxford and AstraZeneca Plc.

The results add to a growing body of evidence that the vaccines’ protection against severe disease and death holds up even as the waning of protective antibodies over time allows more breakthrough infections. Data collected in Texas showed unvaccinated people were 20 times more likely to die from the virus than those who were fully protected.

Such results will likely bolster the case for countries to treat Covid as endemic, causing a mostly mild malaise among the vaccinated. Mass inoculation eases the strain Covid imposes on local health care systems, preventing overcrowded hospitals and rising demand for intensive care and ventilation—all hallmarks of the crisis in many countries during the early days of the pandemic.

Data gathered from New South Wales also showed vaccination reduced the risk of infection more than 10-fold compared to those who were unvaccinated in the two weeks through Sept. 7. Shots appeared more effective in walling off the virus among teenagers, compared with among older people.