Wed Sep 28

Millions of Australians still haven't had their COVID boosters. What message could convince them now?

Written by Holly Seale, Associate professor, UNSW Sydney

The Halton independent review ^[1] of Australia’s COVID vaccine and treatment procurement has been handed to the federal government, which released the review’s recommendations yesterday. Topping the list of priorities are

public health campaigns designed to encourage sustained booster uptake for those that will benefit […] delivered during 2023 and 2024 to improve coverage.

Around 72% of the eligible population in Australia ^[2] have received their third dose. Fourth dose uptake is reasonably high among older adults (73% of eligible people aged over 65), but only 40% of eligible adults aged 30 to 65 (those with health conditions or a disability) have had their “winter booster”.

Around the world, authorities are rethinking how they encourage maximum vaccine protection.

A ‘new phase’

Earlier this month, the United States government announced ^[3] the start of a “new phase” of its pandemic response. Under its new plan, most Americans could receive a COVID vaccine once a year, in the same way we line up to get an annual influenza vaccine. However, some vaccine experts in the US are concerned the government is “jumping the gun ^[4]” without the data to justify its plan.

There are a few issues with adopting an annual COVID vaccination plan. First, the SARS-CoV-2 virus hasn’t been following a predictable annual pattern of peaks and troughs like influenza does. That makes it hard to predict when the next wave might come. And the way the virus mutates is also unpredictable – we don’t know whether there are new variants of concern on the horizon. But perhaps most importantly, we don’t know how people will feel about getting an annual COVID vaccine.

Internationally, the blame for plateauing vaccine uptake has been placed on missing or inappropriate communication. As suggested ^[5] by David Grabowski, a professor of health care policy at Harvard Medical School,

Public health officials have not communicated clearly when you should get a booster and that it is an important step.

Communication failures

Impersonal, mistranslated and uninspiring government communication ^[6] efforts have dogged the COVID vaccination program from the start. However, is communication failure the biggest issue now? Or does it come down to general fatigue about COVID?

“People are ready to put COVID behind them, and they just want to return to a more normal way of life,” suggests ^[7] William Schaffner, a professor of infectious diseases at Vanderbilt University School of Medicine.

A recent systematic review ^[9] looked at factors associated with acceptance of the first COVID booster dose, based on 14 studies including 104,047 fully vaccinated individuals. This review reported 79.0% intend to accept a booster, while 12.6% said they were unsure.

Not surprisingly, people who have previously received a COVID vaccine are more likely to roll up their sleeves again. Those who may decline the option are those who experienced or have ongoing concerns about adverse reactions and discomfort following COVID vaccination.

While these acceptance figures fluctuate a bit based on current disease patterns and public health policy requirements, it does suggest we’re not likely to see booster coverage climb beyond 80%.

This is a concern because boosters are key to keeping people out of hospital, especially people from high-risk groups.

Confusion damages trust

So how can we continue to encourage uptake? A recent online experiment from Israel ^[10] suggests positive and negative monetary incentives, such as fines or monetary payments, could help get people on board with a seasonal COVID vaccine.

The study authors also mention the use of mandates, but such policies would be extremely difficult to justify ^[11] at this stage in the pandemic, when vaccination is primarily for ongoing individual protection.

While information campaigns alone might not drive uptake like they did earlier in the COVID vaccine program, clear and consistent messaging remains critical. Changing vaccine recommendations has the potential to confuse the public and damage trust and confidence. If any country is going to shift towards a routine periodical COVID vaccine, this must be communicated early and with appropriate justification.

These communication efforts will require coordinated funding as well as support for primary health-care workers responsible for explaining, promoting and delivering COVID vaccines. Unfortunately, we are already seeing reductions in funding for COVID vaccine community engagement programs and vaccine promotional efforts, such as those in the UK.

Learning from others’ mistakes

Finally, messaging also needs to be designed based on evidence and take community perceptions, motivators and challenges into account.

The US Federal Drug Administration recently released a new promotional campaign calling ^[13] on people to “install that update” with a bivalent COVID ^[14] booster vaccine.

The backlash was swift, with some highlighting potential conspiracy theories that could be inferred from the campaign wording and others suggesting ^[15] the US is “now treating its citizens like smartphones”.

As authorities consider another potential shift in the COVID vaccination program, they’ll need to listen to the community and invest in evidence-based approaches to maintain public confidence.