Should we vaccinate all returned travellers in hotel quarantine? It’s no magic fix but it could reduce risks


Catherine Bennett, Deakin UniversityThis week, a returned traveller who was quarantining in South Australia seems to have been infected with the virus during his stay, before testing positive once returning to Melbourne. It’s the latest in a long line of hotel quarantine leaks in Australia.

And in this week’s federal budget, the government has committed to welcoming back over 17,000 Australians stranded overseas over the next year, which will likely place more pressure on our hotel quarantine system.

In light of the seemingly continued spillover of hotel quarantine infections into the community, one researcher raised an intriguing possibility online: should we vaccinate all arrivals on day one of their stay in hotel quarantine?

There may be reasonably high vaccination rates among our arrivals already. But, if not, it’s definitely something worth thinking about.

In my view, overseas travellers should be considered equivalent to frontline workers, as they traverse the routes into Australia and cross through border quarantine. Therefore, they could be included in phase 1a of the vaccine rollout alongside these frontline workers.

It’s complex and there’s a lot to take into account, and vaccinating all arrivals won’t be the magic fix to our hotel quarantine troubles. But it might take the edge off some of the transmission risks.

You only have to prevent one case, which could have otherwise led to community spread and lockdown, for such a scheme to pay for itself many times over.

Here’s how it could work.

Vaccinating all arrivals could reduce infection risk

There are a number of potential ways this strategy could reduce infection risk, by:

  • preventing severe illness in people already infected
  • reducing the chance returnees will pass the virus on if they are infected, or become infected
  • protecting them from infection should they be exposed to the virus while in quarantine.

A Public Health England study found that a case who has had a single dose of either the Pfizer or AstraZeneca vaccine is up to 50% less likely to pass the virus on to their close household contacts.

However, when the researchers looked more closely at the timing, they found the full 40-50% reduction in transmission risk only occurred when the case received their first dose five or six weeks before becoming infected. In fact Pfizer didn’t reduce the transmission risk cases posed to others unless the first dose was given at least 14 days before the case became infected. In other words, giving returned travellers a dose of Pfizer while in quarantine might be too late to protect others.




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In saying that, the same study shows AstraZeneca’s vaccine does appear to at least partly reduce the transmission potential of cases even when the dose is given on the same day that person was infected.

In those who’ve received the AstraZeneca vaccine on day zero of their infection, the chance of them transmitting the virus to their close contacts over the ten days or so they’re infectious was on average roughly 20% lower than positive cases who weren’t vaccinated.

Getting the AstraZeneca vaccine when exposed to the virus, or soon after, might therefore marginally protect the wider population if, for example, a traveller contracts the virus late in quarantine and it isn’t picked up in day 12 testing and is released from quarantine.

Both Pfizer and AstraZeneca do provide partial protection from infection within 12 days of the first dose. While this is too late for those already infected, it might still provide some protection from infection for those exposed to the virus in the later stages of their stay in quarantine.

Both vaccines also appear to reduce the risk of subsequently dying from COVID-19 with an 80% reduction in deaths reported in the UK. Some in this study were infected within seven days of their first vaccine dose, but we do not know how this effectiveness against deaths changes with time since vaccination from this report.

Nevertheless, there might be some additional value in offering vaccines to both slightly reduce transmission rates and mitigate against serious illness and death in people who do become infected.

One challenge is that AstraZeneca has more to offer in reducing transmission risk in the first critical two weeks after receiving the first jab, but Australia currently doesn’t advise it for people under 50. Pfizer is in limited supply and our vaccine rollout phase 1a and 1b recipients haven’t all been fully vaccinated yet. The relative risks and benefits of reallocating some of our vaccine supply and delivery must be carefully thought through.

Many of those arriving in Australia will likely have opted for vaccination before travel, if available to them, even if just to increase their chances of testing negative and being allowed to board their flights home. Many are arriving from countries that began their vaccination programs months before Australia.

How many returnees are already vaccinated?

The number of positive cases in hotel quarantine has grown month on month, from 160 in February to 469 in April.

New South Wales provides the most detailed information on returned travellers. Its latest surveillance report on about 21,000 returnees shows 180, or 0.8%, tested positive to COVID-19. About 75% of these positive cases tested positive by day two, suggesting they were exposed before arriving in Australia or in transit.




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The report does include information on how many arrivals have been vaccinated since March 1. Of the 302 positive cases reported to the start of May, 20 had been vaccinated, with six fully vaccinated (two doses at least two weeks prior) and 14 partially vaccinated. Although, those considered “fully vaccinated” might not have been two weeks post-vaccine at the time they actually contracted the virus.

We haven’t been provided the overall vaccination rates for returnees across Australian hotel quarantine, so we can’t yet work out what percentage of arrivals are vaccinated. But if this is quite low, it strengthens the argument for offering vaccines to travellers on arrival.The Conversation

Catherine Bennett, Chair in Epidemiology, Deakin University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

How other countries get parents to vaccinate their kids (and what Australia can learn)



Different countries take different approaches to get parents to vaccinate their children. But saying which one works best is difficult.
from www.shutterstock.com

Katie Attwell, University of Western Australia and Mark Navin, Oakland University

Countries around the world, including Australia, are using different ways to get parents to vaccinate their children.

Our new research, published this week in the journal Milbank Quarterly, looks at diverse mandatory vaccination policies across the world. We explore whether different countries mandate many vaccines, or just a few; if there are sanctions for not vaccinating, such as fines; and how easy it is for parents to get out of vaccinating.

This is part of ongoing research to see what Australia could learn from other countries’ attempts to increase childhood vaccination rates.




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The shift from voluntary vaccination

Until recently, many governments preferred vaccination to be voluntary. They relied on persuasion and encouragement to try to overcome parents’ hesitancy or refusal to vaccinate their children.

However, recent measles outbreaks have made those methods less politically tenable. The rise of pro-vaccination activism and the polarisation of public debate about immunisation policy has motivated governments to take a more hard-line approach.




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Early evidence from Italy, France, California and Australia indicates this has led to higher vaccination rates. But different countries have pursued very different policies.

Australia’s federal “No Jab, No Pay” policy removes entitlements and childcare subsidies from unvaccinated families. Four Australian states also have “No Jab, No Play” policies to limit vaccine refusers’ access to childcare.




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California bans unvaccinated children from school, and Italy fines their parents. France classifies vaccine refusal as “child endangerment” and can impose hefty fines.

Some governments can use more than one method at once, like Australia’s mix of state and federal policies. Italy’s new policy uses a combination of excluding unvaccinated children from daycare and fines for parents.

Making it hard to refuse

Australia, Italy, France and California make it difficult for parents to refuse vaccines by only permitting medical exemptions to their mandatory policies.

However, other jurisdictions ultimately allow parents to refuse vaccines, albeit using different methods. For example, Germany and the state of Washington require parents to be counselled by medical professionals before they obtain an exemption to vaccinating their child. In Michigan, public health staff provide a mandatory education course for parents seeking non-medical exemptions.

Which policy leads parents to vaccinate?

We can assess a policy to get parents to vaccinate using a notion called “salience”. Put simply, will a vaccination policy actually make parents vaccinate?

For example, Australia’s federal vaccine mandate has become more salient since parents can no longer obtain conscientious objections and risk losing benefits for not vaccinating.

But there are other factors to consider, such as whether a policy promotes timely vaccination.

Australia’s “No Jab, No Pay” policy applies to children from birth, so it motivates parents to vaccinate on time. But the United States has state-level policies that prompt parents to have their children up-to-date with their vaccinations when they start daycare or primary school.

Who doesn’t have to vaccinate?

Another important question is who gets to duck away from the hand of government. Australia’s “No Jab, No Pay” policy leaves wealthy vaccine refusers untouched as they are ineligible for the means-tested benefits docked from unvaccinated families.

And Australian states’ policies to exclude vaccine refusers’ children from daycare doesn’t affect families who don’t use daycare.

Since France and California exclude unvaccinated children from school, these countries have the capacity to reach parents more equitably (almost everyone wants to send their kids to school so more people are incentivised to vaccinate). In both places, you can homeschool if you really don’t want to vaccinate.

Addressing the many reasons for not vaccinating

Mandatory vaccination policies also need to recognise the two types of parent whose child might be unvaccinated. Much airtime focuses on vaccine refusers. However, at least half the children who are not up-to-date with their vaccines face barriers to accessing vaccination, such as social disadvantage or logistical problems getting to a clinic. They are the children of underprivileged parents, not vaccine refusers.

When it comes to the vaccination status of disadvantaged children entering daycare, Australian states have chosen a “light touch” as part of the “No Jab, No Play” policy. Existing state policies provide grace periods or exemptions for these families.

But the federal “No Jab, No Pay” hits all parents where it hurts, and offers no exemptions or grace periods to disadvantaged families. Likewise, California’s school entry mandate makes no such exceptions. Italy and France have daycare exclusions similar to “No Jab, No Play” in their policies, but we have not found any evidence they make exceptions for disadvantaged families.




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Finally, mandatory vaccination policies vary on how much they cost for governments to deliver. Oversight of parents, such as inspections or implementing fines, can drain government resources. And educational programs for parents seeking exemptions are expensive to run.

Governments can outsource some of these costs to parents (for instance, parents may have to pay a fee to see a doctor for an exemption).

Governments can also hand over the tasks to medical professionals, but then they have less control over what these professionals do. For instance, California is now seeking tighter regulation of doctors who say children are eligible for medical exemptions. This monitoring will cost the state, but will allow greater oversight. Victoria also had problems with doctors who accommodated vaccine refusers.

So where does this leave us?

Our work investigating international strategies to get parents to vaccinate their children is ongoing. Australians seem strongly attached to our vaccine mandates. But both state and federal policies have undergone tweaks since their inception.

Any future adjustments should ensure all parents are targeted, that disadvantaged families are not further disadvantaged, and that we make it very easy for everybody to access vaccines in their communities and on time.

Globally, as more jurisdictions move away from voluntary child vaccination to mandatory policies, we need to get a clearer picture of how these policies work for families, government and the policy enforcers, including school staff and health professionals.The Conversation

Katie Attwell, Senior Lecturer, University of Western Australia and Mark Navin, Professor, Department of Philosophy, Oakland University

This article is republished from The Conversation under a Creative Commons license. Read the original article.