ACT’s 95 per cent vaccination rate is only temporary without timely boosters for all

Karyn Starmer 8 November 2021 66
Dr Andrew Jeremijenko

Aspen Medical Group Medical Director Dr Andrew Jeremijenko. Photo: Aspen Medical.

While the ACT gives itself a well-deserved collective pat on the back for achieving the milestone of 95 per cent double-dose vaccination for its 12-plus population, medical researchers are warning that without timely booster shots, the population could find itself back to below herd immunity levels and at risk of a third wave.

Research published in The New England Journal of Medicine found Pfizer vaccines offered at least 90 per cent protection against severe COVID-19 cases for at least six months; however, six months after the second Pfizer dose, the vaccine provided less than 20 per cent protection against milder infections of the virus.

The co-author of the research, epidemiologist and Aspen Medical group medical director Andrew Jeremijenko, said that with immunity waning after six months, the effective 95 per cent vaccination rate would start to drop.

“The first groups of essential workers were receiving their second Pfizer dose around April this year so they are due for boosters now. Without boosters, as each individual reaches the six-month mark, they will effectively move out of the 90 per cent protected group and the overall population vaccination rate will progressively slide down to below herd immunity levels,” Dr Jeremijenko said.

Dr Jeremijenko said the vaccines will remain effective against severe infection, resulting in hospitalisation and death, for longer than six months, but noted with waning effectiveness, the chance of acquiring the virus and passing it on will increase.

A study undertaken by University of Oxford scientists published in August found that the effectiveness of the Pfizer vaccine declines slightly faster than that of AstraZeneca.

Without booster shots, Dr Jeremijenko suggested Australia may end up with a similar experience to Israel which had a spike in cases six months after its vaccination program started, creating a third wave.

Like Israel, Australia has experienced very low infection levels from the SARS-CoV-2 virus compared with other countries. Dr Jeremijenko says this means boosters are crucial to maintaining herd immunity.

“Places where infection rates were low will be especially reliant on booster shots to prevent further waves,” Dr Jeremijenko said.

This is different for countries like Qatar where SARS-CoV-2 infection rates were higher.

A Qatar study co-authored by Dr Jeremijenko showed that prior infection was associated with a lower risk for breakthrough infection among persons receiving the mRNA vaccines like Pfizer and Moderna, meaning natural immunity from infection together with vaccination together lasts longer than vaccinated immunity.

Several recent studies showed Moderna’s shot elicits a stronger and longer-lasting immune response than the Pfizer jab. Some scientists believe this is because Moderna’s mRNA dose is more than triple that of Pfizer.

While studies are continuing, Dr Jeremijenko says it was clear that while vaccine efficacy waned over time, every country would probably need to follow Israel’s lead in administering boosters to its entire population with older adults and those in a clinical risk group prioritised for booster doses.

The ACT Government has opened bookings for its booster shot program. People who received the vaccine at least six months ago are now eligible for their top-up.

What's Your Opinion?

Please login to post your comments, or connect with
66 Responses to ACT’s 95 per cent vaccination rate is only temporary without timely boosters for all
Brianna Brianna 10:22 am 12 Nov 21

My husband and I are both double vaxxed and we both contracted covid. My husband has recovered fairly well but I am still struggling with my recovery. I have very weak muscles and am still very tired all the time. It affects all people differently.

Kel Senior Kel Senior 11:27 pm 11 Nov 21

So far every staff member at my workplace who has had booster have had days off with bad side effects/sick from booster😭 Yeah Yeah ... better than getting COVID but 1) 😭 they are so unwell & 2) it sure is hard being very short staffed due to it!

Robert Harrop Robert Harrop 12:45 pm 10 Nov 21




These words mean so much to so many.

If you have CHOSEN to be Vaccinated against COVID, that's great you' ve been able to exercise your RIGHT TO CHOOSE.

I too am exercising that right, however I choose not to have it.

My choice does not put you in danger.

Do not shun, judge or denigrate those that are exercising their right not to have it.

Am.I denigrating you and your choice?

The media and the Government are.not supporting our Democratic rights nor or Constitution.

Being vaccinated does not make you superior to anyone else.

Nor does it give you the right to look down on those that aren't.

Futureproof Futureproof 4:42 am 10 Nov 21

How about I just get a transfusion of Pfizer. Will that do?

Matthew Pez Matthew Pez 7:39 pm 09 Nov 21

Here we go again

Daniel Duncan Daniel Duncan 5:22 pm 09 Nov 21

how many? 1,2 .. 50? for how long? will they make the contracts public?

Sher Bee Sher Bee 5:14 pm 09 Nov 21

Anti vaxers, please Google long covid

    Josh Ongley Josh Ongley 6:41 pm 09 Nov 21

    Sher Bee don’t you mean please watch the project 😂😂😂

    Vida Honnêteté Vida Honnêteté 2:34 pm 10 Nov 21

    Sher Bee sadly even fully vaccinated can contract COVID and suffer long COVID. It is an awful virus. Not one of us is guaranteed immunity. It's significant to remember that the current tranche of available vaccines were developed for the alpha strain not the delta variant. Hopefully new advances will afford some increased protection specific to the delta variant and possibly other variants.

TimboinOz TimboinOz 3:31 pm 09 Nov 21

Everyone who HAS had both shots already – does need to wait 6 months from their second shot. In our case that means we wait until February. And we were in what was called the 1b grouping. which puts us among the earliest to receive both shots!

In that case, where’s the URGENCY?!

So, I’d respect your posts a whole LOT more, if that factor was incorporated in all future posts by you, Karyn!

That it hasn’t been mentioned up to now, rather diminishes your accuracy and probity!

We WILL have our booster shots – in February. When they will work!!

    Shay Daisy Shay Daisy 2:04 pm 10 Nov 21

    I’d suggest the urgency is for the 1a frontline workers who were vaccinated in March/April. High risk due to occupation and in need of third jab to manage waning immunity. Don’t want them waiting until after Christmas, or “later” when it is convenient.

Vida Honnêteté Vida Honnêteté 2:38 pm 09 Nov 21

Herd immunity can't be claimed to have been reached when the most recent, peer reviewed LANCET study of 29 October 2021 clearly states that our current vaccines have "minimal" effectiveness on transmission. We need to rely on the available, validated, peer reviewed facts and evidence:

Our high vaccination is great for protection from COVID on an individual basis but we all need to stay acutely aware that protection re transmission is, as reported in the findings of this current (29 Oct 2021) The LANCET study, "minimal" - despite full vaccination (quoted from LANCET):

"This study confirms that COVID-19 vaccination reduces the risk of delta variant infection and also accelerates viral clearance in the context of the delta variant.

However, this study unfortunately also highlights that the vaccine effect on reducing transmission is minimal in the context of delta variant circulation. These findings have immediate public health implications.

Research efforts should be directed towards enhancing existing vaccines or developing new vaccines that also protect against asymptomatic infections and onward transmission. Until we have such vaccines, public health and social measures will still need to be tailored towards mitigating community and household transmission in order to keep the pandemic at bay.”

    Lin Van Oevelen Lin Van Oevelen 6:06 pm 09 Nov 21

    Vida Honnêteté There are a lot of caveats in there. Including the possibility that waning immunity may have had an effect. Which is exactly what this article is about.

    Vida Honnêteté Vida Honnêteté 7:09 pm 09 Nov 21

    Lin Van Oevelen It's the Lancet - credible, peer reviewed, published results of their study findings dated 29 Oct 2021. You can read the full 13 page study results including detailed methodology or just read the summary.

    Yes, a thorough study needs to examine variables etc. That is to be expected and is necessary.

    I'm not sure what point you are trying to make re "waning immunity" as yes, the current vaccines have been examined in the study in order to ascertain when their effectiveness wanes.

    None of the COVID vaccines have ever been claimed to produce "immunity". Their role is to protect those infected from serious illness, hospitalisation and death.

    Transmission is, has and always was declared as NOT being able to be eliminated by the vaccines. In the same way the vaccines cannot eliminate the risk of contracting COVID and nor has anyone ever claimed that they can.

    Lin Van Oevelen Lin Van Oevelen 7:16 pm 09 Nov 21

    Vida Honnêteté The reference to waning immunity is literally in the study you shared. And they mention other variables that were not accounted for in their results. It definitely is a great basis for more research but it doesn't yet give the whole picture. Especially in regards to community transmission too as a shorter period of being infectious would have more of an effect there than it would have amongst household contacts.

    It's the scientists who conducted the research giving their interpretation of the results in the summary. Reading the 13 page study is hardly going to change that as they are far more capable at interpreting this than I am.

    And protection against severe illness is still immunity.

    Vida Honnêteté Vida Honnêteté 10:13 pm 09 Nov 21

    Lin Van Oevelen you are free to ignore the Lancet study if you so wish. Some people are definitely unable to get over their own biases irrespective of credible studies and findings.

    They want to hold onto their misperceptions and claims made in now well out dated research regardless of emerging data and information.

    Tim Palmer Tim Palmer 5:01 pm 10 Nov 21

    You are missing the point, possibly deliberately. Even if the transmissiability of the virus by infected vaccinated vs infected unvaccinated was the same (which it isn't) the transmission by the vaccinated population would be insignificant compared to transmission by the unvaccinated population because so few of the vaccinated will be infected. If you have a hundred vaccinated people of which five get infected (breakthroughs) compared to 100 unvaccinated people of which 80 get infected, the likelihood of transmission from the uninfected population of 100 is 16 times higher even if the infectiousness of all infected people was equal.

chewy14 chewy14 1:42 pm 09 Nov 21

The ACT has not achieved herd immunity for Covid. Nowhere in the world has achieved herd immunity.

It’s fine to promote the benefits of vaccination amd booster shots, but at least be honest about why.

    TimboinOz TimboinOz 3:32 pm 09 Nov 21

    Too right, Chewy and see above for another factor.

Linda Stapleton Linda Stapleton 1:25 pm 09 Nov 21

I always turn off when I hear or read the phrase 'herd immunity' ... dont get me wrong I understand it but quite frankly it will not stop a vunerable person catching a virus if it is out there still and it can be. Also someone else having the vaccines will not stop a person who can not have the vaccine due to medical reasons, from dying from the virus, if they catch it... so yes I turn off and wonder at the excitement it creates in some people...

    Lin Van Oevelen Lin Van Oevelen 6:01 pm 09 Nov 21

    Linda Stapleton A high vaccination rate significantly reduces the covid transmission rate. Just like restrictions and lockdowns did.

    Vida Honnêteté Vida Honnêteté 3:41 am 10 Nov 21

    Lin Van Oevelen not according to the current LANCET study findings of 29 October 2021. Please provide the peer reviewed, current source reference upon which you rely to keep making your otherwise unsubstantiated claim.

    Facts, research, study results and data are reliable to a far,far greater extent than someone on Facebook offering an unsubstantiated opinion without providing any source to back it up.

    Linda Stapleton Linda Stapleton 11:01 am 10 Nov 21

    Lin Van Oevelen and still if a vunerable person can not get the vaccine, you getting it will not save their life if they catch covid...

Clare Hyden Clare Hyden 1:12 pm 09 Nov 21

This is sad. What about all the developing countries still looking for first doses? We have hardly any community transmission even as cases ease. Evidence of benefits of third dose and when it should be administered is limited.

Kriso Hadskini Kriso Hadskini 1:06 pm 09 Nov 21

Yep, no matter how far we go, there is always more pfizer money to make. The scary thing is if in he future long term studies show negative effects to too much vaccine (ie boosters) they will never admit it or make it public because to cost to govt covering liability would be astronomical.

    Russell Nankervis Russell Nankervis 1:56 pm 09 Nov 21

    Kriso Hadskini it costs more to care for someone in hospital than giving them a vaccine though

    Craig Fitzgerald Craig Fitzgerald 7:23 pm 09 Nov 21

    Kriso Hadskini Pfizer or the government can't be accountable for anything in the future

    Nada Krstin Nada Krstin 10:58 pm 09 Nov 21

    Craig Fitzgerald how so?

    Understand Pfizer pharma company may be able to avoid accountability if something goes wrong (as proven by their many historical lawsuits), but how the gov if they have enforced & mandated?

    Just hope this may never be the case...

    Craig Fitzgerald Craig Fitzgerald 11:04 pm 09 Nov 21

    Nada Krstin it was part of the whole approval.

    As for the government they have talked alot about mandates and enforcement but have they become law?

    Nada Krstin Nada Krstin 12:37 am 10 Nov 21

    Craig Fitzgerald well seems that way when gov state & federal employees currently/now do & have lost their employment/jobs unless vaccinated - how is that not the law?

    Chris Mitchell Chris Mitchell 6:49 am 12 Nov 21

    Kriso Hadskini, they won't be sued as the government has already stated that the government or pharmos can't be sued from any side effects from the vaccine. They are nice and safe.

Kate Eliza Kate Eliza 12:24 pm 09 Nov 21

It wasn't long ago I said there will be boosters and no such thing as FULLY vaccinated and I was told I was a conspiracy theorist! Yet .... here we are. 😄

Oscar Mike Oscar Mike 11:30 am 09 Nov 21

My Pfizer shares !

Janet Mulgrue Janet Mulgrue 11:01 am 09 Nov 21

Funny how no one bats an eye at having a flu vaccine every year but carry on like idiots about having a COVID booster.

    Kate Eliza Kate Eliza 12:25 pm 09 Nov 21

    Niko I never have. Never had the flu.

    Jesse Peter Jesse Peter 12:48 pm 09 Nov 21

    exactly how much of the population do you think gets the flu shot?

    Yvonne Gardner Yvonne Gardner 12:51 pm 09 Nov 21

    Janet Mulgrue 🙄 bit different don’t you think, hardly a comparison

    Janet Mulgrue Janet Mulgrue 12:53 pm 09 Nov 21

    Yvonne Gardner why because it’s new?

    Kriso Hadskini Kriso Hadskini 1:09 pm 09 Nov 21

    Janet Mulgrue I dont, not everyone hands their health over, some of us do it by not smoking, being a decent weight and exercising. Have never had flu my whole life.

    Steve Jones Steve Jones 1:28 pm 09 Nov 21

    Kriso Hadskini clearly don’t have kids or work with the public

    Belinda Anne Belinda Anne 2:24 pm 09 Nov 21

    Yvonne Gardner worked in disability 16 yrs and was never "mandated" to get flu shot or lose my job

    Yvonne Gardner Yvonne Gardner 2:44 pm 09 Nov 21

    Janet Mulgrue nothing to do with being new

    Lin Van Oevelen Lin Van Oevelen 5:58 pm 09 Nov 21

    Kriso Hadskini I only started getting my flu shot after the pandemic started. Only had the flu twice in my life and it was because I was run down looking after a baby on my own. I got the flu shot to reduce my risk of infecting others. The exact same reason why I got my covid shots and will get my booster.

    Josh Ongley Josh Ongley 6:35 pm 09 Nov 21

    Lin Van Oevelen oh so not to protect yourself then.

    Lin Van Oevelen Lin Van Oevelen 6:47 pm 09 Nov 21

    Josh Ongley Well no. I'm obviously not prone to getting the flu. Nor am I in a high risk group for covid but protection from severe illness definitely is also a factor there as it's not anything like the flu.

    Garvin Francis Garvin Francis 8:41 pm 09 Nov 21

    Janet Mulgrue or having botox injections cause they want that in their body

    Edna Brooke Jessop Edna Brooke Jessop 8:56 pm 09 Nov 21

    Janet Mulgrue not because its new but because the flu shot isnt mandatory for everyone! The flu shot is a choice, dont like the choice then you had the opportunity to find another line of work...

    Nada Krstin Nada Krstin 10:34 pm 09 Nov 21

    Garvin Francis what, how is botox relevant to this post or to the covid vaccine??

    umm anyone that chooses to get botox botulin bacteria for cosmetic reasons is their own consensual choice - not mandated - and they consent to the risks. Not my choice but peeps are free to do what they want consensually to have in their body.

    Also note that botox is medically endorsed to treat certain muscular conditions, severe migraines etc

    Vida Honnêteté Vida Honnêteté 3:34 am 10 Nov 21

    Janet Mulgrue a flu vaccine is once yearly. Not every 6 months. Now some suggest a booster every 4 months for COVID and how frequently is acceptable? Every month?

    The current tranche of COVID vaccines were developed for the Alpha strain not the now prevalent, highly transmissable and highly infectious Delta strain.

    Unfortunately unless newer vaccines are developed for the Delta strain and in preparation for likely other emergent variants, the current vaccines' already limited effectiveness will continue to wane and wear off as it has been demonstrated already. That is why we are now chasing it with the hope that a booster at 4 - 6 months MIGHT help.

    We do have to remember that the current COVID vaccines were not developed for the Delta variant.

    Garvin Francis Garvin Francis 6:22 am 10 Nov 21

    People who choose not to be vaccinated argue that they don't know what's in it. They don't know what's in botox either but they still choose it.

    Adam Ciaccia Adam Ciaccia 11:13 am 10 Nov 21

    Jesse Peter it’s less than 25% I believe…

    Chris Mitchell Chris Mitchell 6:52 am 12 Nov 21

    Janet Mulgrue. Not everyone has flu shots every year though. I certainly don't as I rarely get the flu. First time was 33 years ago.

Kathleen Beck Kathleen Beck 10:22 am 09 Nov 21

Sorry we don't make Pete Evans rich anti vaxxers.

Michael Byrne Michael Byrne 10:17 am 09 Nov 21

Because it's not an immunisation program, but a band aid.

    デ スティーブ デ スティーブ 10:33 am 09 Nov 21

    Michael Byrne, it's an Immunisation program which gives you specific antibodies to a specific virus your body has never seen anything like before.

    Unfortunately, much like influenza H1N1 and other viruses, it will mutate, and those specific antibodies will become less effective. Additionally your post-Immunisation SARS-COV-2 specific antibodies levels will decrease, just the same as they do for tetanus.

    For context, Tetanus Immunisation is a program of 5-shots + recommended booster every 10-years. It took 15-years before the dosing regime for tetanus was fully refined. This is no different, as we learn more about long term immunity, breakthrough infections, viral mutation, you can expect the Immunisation programme to be adjusted.

    Julie Marshall Julie Marshall 11:59 am 09 Nov 21

    Michael Byrne I’m guessing it’s like the swine flu? It mutated 5 times before it mostly disappeared. Covid seems to mutate.

    Julie Marshall Julie Marshall 10:19 pm 09 Nov 21

    Nada Krstin could only hope so.

Wayne Martin Wayne Martin 10:06 am 09 Nov 21

herd imunity yeh right more hype

    Pam Gulliver Pam Gulliver 11:56 am 09 Nov 21

    Wayne Martin always negative people.. sad!

    Linda Stapleton Linda Stapleton 1:27 pm 09 Nov 21

    Pam Gulliver ever seen the results to a person who can not have a vaccine due to medical issues and who catches the 'virus' and how that herd immunity is absolutely useless to that person????? sometimes it is not negativity, so much as life experience speaking... ..

    Pam Gulliver Pam Gulliver 1:57 pm 09 Nov 21

    Linda Stapleton I worked in hospitals all my life- answer your question!

    Nada Krstin Nada Krstin 10:14 pm 09 Nov 21

    Linda Stapleton I understand where you are coming from, however if been immune compromised all your life - then the issue is with EVERY germ/bacteria that exists and the yearly influenza strain...always - why such focus on current covid only?

    Vida Honnêteté Vida Honnêteté 3:23 am 10 Nov 21

    Pam Gulliver is that how you developed your immunity to displaying empathy and compassion? 🙄 Must have been a snarkiness epidemic going around.

    Colin Mitchell Colin Mitchell 10:02 am 10 Nov 21

    Wayne Martin herd immunity sounds like sheep.

    Clare Louise Clare Louise 10:56 pm 11 Nov 21

    Colin Mitchell actually it's a flock of sheep but nice try.

CBR Tweets

Sign up to our newsletter

Region Group Pty Ltd

Search across the site