Covid 19 coronavirus: Why small number of fully vaccinated people have died of Covid

A small number of fully-vaccinated people in NSW have died of Covid-19, but it shouldn't stop you from getting the jab or cause you to question its efficacy, experts say.

As of yesterday, 36 fully vaccinated residents have died in the Australian state's Delta outbreak, representing around 11 per cent of overall deaths.

As of today, 393 people have died in total, meaning over 350 of those were not fully vaccinated.

There was one fully vaccinated patient among the 15 deaths reported up to 8pm on Tuesday night.

The woman, who was in her 70s and lived in Batemans Bay on the NSW south coast, died at home and had underlying health conditions. She received her second vaccine dose shortly before her death and was diagnosed with Covid-19 following her death, NSW Health said in a statement.

A small number of fully vaccinated people in NSW have died of Covid-19, but it shouldn't perturb you from getting the jab, experts say. Photo / George Heard

Vaccination remains imperative to moving forward against Covid-19

People who have received both doses of the jab are 70 to 95 per cent less likely to get sick from the virus, compared to those who've had neither, according to NSW Health.

"Vaccination is the way out of this current issue in NSW and being vaccinated is the single most important step you can take to protecting yourself, your family and your community," NSW Health Minister Brad Hazzard said during today's update.

In New Zealand, Prime Minister Jacinda Ardern announced today: "We need everyone to be double vaccinated. Only three per cent of people in this outbreak were double-vaccinated."

She said achieving 90 per cent was possible: 92 per cent of over-65s had had at least one jab.

"It is possible to hit 90, and we need everybody to put that effort in.

"If you are someone who is reluctant to get your first dose, please talk to someone else, It will help.

"We are at the hard end now. Those who took no convincing, they're done."

According to the most recent detailed breakdown of NSW Health data, as of September 11, 20 of the (then) 21 fully vaccinated people who had died were aged 70 or more. Of the 15 fully vaccinated people to have died since, eight had underlying health conditions.

"As the proportion of the population who are vaccinated increases, the numbers of cases who are fully vaccinated will increase but this does not mean the vaccines are not working," NSW Heath noted in the surveillance report.

"The main thing to pick up on here is that about 11 per cent of people dying are fully vaccinated, but in the groups most likely to die (over 70 year olds, people with vulnerabilities), about 80 per cent are fully vaccinated," James Cook University professor of infectious disease and epidemiology, Emma McBryde, told news.com.au.

"These two pieces of information together suggest a strong protective effect of vaccination of around a 30 to 40 fold decreased risk of death in the vaccinated."

A handful of deaths from the virus in the fully vaccinated, McBryde added, is not unexpected "because no vaccine is perfect and they lower your odds dramatically [of contracting the virus] but not completely".

Research fellow at Monash University's Allergy and Clinical Immunology Laboratory, Dr Emily Edwards, agreed, telling news.com.au that while unfortunate, "a small number of deaths will occur in the fully-vaccinated as the vaccine is not 100 per cent effective".

"We need to bear in mind that it takes a couple of weeks after your second dose to build full protection, so that second dose is crucial," Edwards added.

"Also, there are a small percentage of people with additional risk factors including age and being immunocompromised who are not fully protected by the vaccine."

Who is likelier to be at risk of a 'breakthrough' infection?

Individuals who may have a compromised immune response to the jab, Edwards explained, are those "with immunodeficiencies where a part of the immune system is missing or does not function adequately".

"Primary immunodeficiencies are caused by DNA mutations, and are rare and often inherited. Secondary immunodeficiencies are more common and acquired after birth as a result of numerous external factors including chronic infections such as HIV, malnutrition, cancer and certain treatments," she added.

"These vary in severity depending on the part of the immune system that is missing and the degree to which function is impaired.

"Those who receive high dose immunosuppressants including bone marrow and solid organ transplant patients, and serious forms of primary immunodeficiency … are at the moderate to severe end of this spectrum.

"Additionally, those older in age have modest immune deficits that weaken their ability to respond to infection and vaccination. This makes them more susceptible to severe Covid-19 infection."

While some patients with immunodeficiencies can make responses to the vaccine, "these responses are usually lower than in healthy individuals", Edwards said.

"There has also been shown to be a lower level of response to the Pfizer vaccine in older individuals compared to younger individuals," she added.

"This decreased immunity can lead to breakthrough infections."

In England, out of more than 51,000 Covid deaths between January and July this year, only 256 occurred after two doses, mostly in people at very high risk of illness form the virus.

Outreach programs such as a the Shot Cuzz bus are trying to help us reach our 90 per cent target. Photo / Michael Craig

The Office for National Statistics said the figures show the high degree of protection from vaccines against illness and death.

In the United States, it was a similar story until recently, with the Centres for Disease Control and Prevention estimating that fully vaccinated people accounted for less than one per cent of virus deaths.

In August, though, the agency noted that those figures did not reflect new data involving the Delta variant and said it was actively working to update them.

- Additional reporting, NZ Herald