How Many Australians Need to Be Vaccinated Before We Can Avoid Lockdown

Lockdown Australia

With a lot of the country now either in lockdown or teetering on the edge, it seems like Australia has really let slip the advantage we had over COVID.

We were doing so well! We were the envy of the world! While America and the UK were in lockdown with COVID running riot, we were going to gigs, meeting friends in restaurants, and licking the faces of every passing stranger.

Ah, happier times. Simpler times. Now with the new Delta variant in our midst, it looks like that advantage has well and truly slipped away and we’re going to have to vaccinate our way out of this mess. If only we’d treated the whole thing as a race and not become complacent because there wasn’t any COVID here, huh?

With some of the lowest vaccine numbers in the OECD, it’s going to take us a while to get to the point where we can ‘live with the virus’ — if that’s an option at all.

What are the target vaccination rates we need to hit in order to avoid the rolling lockdowns and ongoing restrictions? Well, it’s a little complicated, but here’s what we know.

Herd immunity

While 100% vaccination sounds like it should be the target — and in an ideal world, we would all be immune to COVID — it’s actually not possible, nor is it necessary.

There are people out there who can’t get the vaccine right now. Herd immunity, instead of total immunity, is the practical means by which we protect them without a vaccine.

Herd immunity is achieved when enough people within a group become immune to infection so that it is no longer able to spread freely in a community.

We did this with polio and smallpox. Even though those diseases still exist, enough of us are immune to them that they can’t effectively spread.

Even if one person has the infection, if there are no viable hosts for that virus to jump to, it will quickly die out.

Herd immunity is the absolute gold standard that we want to achieve. However, there are unfortunately a good number of reasons why we might not be able to achieve that with COVID-19.

Normality, not immunity

Scientists are now moving away from the idea that we’ll be able to achieve herd immunity with COVID-19.

For starters, we don’t know the level of vaccination needed across a population to stop the transmission of COVID-19 but it’s probably around 70%. Some estimates say it’s around 60% while others put it at 80% or more.

The Australian government has said we’re looking to hit a vaccination target of around 70% before lockdown measures can be rescinded. The government has commissioned modelling to be conducted on the exact number we would need to hit before things can return to normal but as of yet, that information is unknown.

Vaccine hesitancy, the delayed arrival of vaccinations suitable for children, and, most of all, the emergence of new COVID variants, has led scientists to believe that we won’t be able to effectively hit this number and vaccinate our way out of the pandemic.

We also are still uncertain about how long immunity might last from a vaccine against COVID, with some thinking the virus could become a seasonal epidemic like the flu.

This reflects the complexities and challenges of a global pandemic but it shouldn’t make the vaccine rollout seem ineffective.

“The vaccine will mean that the virus will start to dissipate on its own,” epidemiologist Lauren Ancel Meyers has said. “We may find ourselves months or a year down the road still battling the threat, and having to deal with future surges”.

This is obviously terrible news. The good news however is that we might not have to achieve herd immunity to return to some semblance of normality.

So, what can we do?

‘Living with the virus’ is a phrase trotted out by those who oppose lockdown at any price. It’s not a completely terrible idea, just one that can’t happen right now.

COVID-19 and its variants are dangerous, highly transmissible, and pose both short and long term health risks to those who catch it.

Vaccination is one way to reduce the impact of COVID, if not the transmission.

Vaccine transmissibility is rated on an R-value scale. The higher the number, the more transmissible. What epidemiologists do in their modelling is base the spread of a virus on the random interaction of people within the population.

However, people don’t interact randomly, they actually interact in highly structured, routine ways. That could mean that a rate much lower than 70% could be needed before herd immunity kicks in. Couple this with the fact that we might only need to vaccinate certain categories of people and the rate needed could be as low as 30%.

Human behaviour, however, also works against us. Once more people are vaccinated, the more likely we are to engage in risky behaviours that promote the spread of the virus.

We also can’t forget the fact that the vaccine rollout is not uniform. While Australia, with 11% of its population fully vaccinated, is behind, say, Mongolia, with 60% of its population vaccinated, we’re far ahead of Nigera, which has only 0.68% of its population vaccinated.

That means of course that while some populations can be relatively immune to COVID, others won’t be. While there is still the danger of COVID being transmitted across borders and mutating in populations with high case numbers, border restrictions will likely remain in place for some time.

This being said, with a high vaccination rate, it’s likely that we will be able to remove some of those restrictions before hitting the magical 70% target.

The UK has recently — and, some have said, recklessly — removed all COVID-19 restrictions, even though its case numbers are in the tens of thousands each day.

That’s because the UK has managed to fully vaccinate some 55% of its population, with 70% having had at least one dose. This hasn’t stopped transmission of course, but it has rapidly decreased the number of deaths and hospitalisations.

Singapore too has decided to live with the virus. With 47% fully vaccinated, and 73% with a single dose, Singapore is planning to open the country up without COVID restrictions over the next few months.

NSW Premier Gladys Berejiklian has said that about five million people in the state would need to be fully vaccinated before borders open — around 80% of the state.

With that in mind, mid-2022 is the projected timeline for when we might hit those targets. Even though this won’t give us complete immunity to the virus, at some stage, we will simply have to open up and learn to live with the virus as its impact is lessened by the vaccines.

For the initial part of that transition, lockdowns and restrictions could remain in place, but as we experiment with new ways of living, it ought to become easier to go about our daily lives.

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