Infectious disease specialist Dr Nick Coatsworth addresses Covid-19 vaccine booster questions

A specialist in infectious diseases has addressed the “mixing and matching” of vaccine doses as Australia’s booster rollout begins.

Infectious disease specialist Dr Nick Coatsworth has shared his thoughts on Australia’s vaccination plan moving forward, addressing common questions surrounding the immunisation of children in the 5-11 age group and the effectiveness of booster shots.

Appearing on The Project on Monday night Dr Coatsworth, who was formerly one of Australia’s deputy chief medical officers, took questions from hosts Waleed Aly, Carrie Bickmore and Virginia Trioli over the developing issue.

Monday marked a major day in Australia’s vaccine rollout with the nation hitting its 80 per cent fully vaccinated target for over 16s . After a slow start, Australia’s widespread acceptance of the new technologies trialled in jabs (such as Pfizer and AstraZeneca) has put it on track to become one of the most inoculated nations around the globe.

However, when asked whether vaccinating children as young as five was the best move forward for the nation, Dr Coatsworth admitted “we really don‘t know the answer to that”.

“That’s the honest truth. I mean, of course, it is under emergency youth authorisation to vaccinate children between five and 11 in the United States,” he said.

“But it’s a very different situation over there, where a lot of their adults have not got vaccinated. So what we have to do is weigh up the risks and the benefits.”

Dr Coatsworth said children were a group “that gets very mild disease and doesn‘t transmit as readily”, but he also said vaccination was something to consider if it was proven inoculation of kids would indeed help control community spread.

Currently, the rate of infections in under 10s has tripled, with the age group now accounting for the most cases in Victoria. Thirty-nine children have been admitted to ICU during this wave.

“It’s as though people think that paediatrics ICUs have been empty just waiting for Covid,” Dr Coatsworth continued.

Dr Nick Coatsworth on The Project. Picture: Channel 10

“It’s not the case. They’re obviously busy all the time and often because of infectious diseases. When we say tripling, they’re tripling off a low base and, as you say, in Melbourne, there are kids going to ICU.

“But they’re coming out. They’re getting the care that they need. So we don’t want to overstate the risks. But equally, if the benefits outweigh the risks of giving vaccines, we should go ahead and do it.”

Dr Coatsworth said the nation’s previous goal of herd immunity against the virus wasn’t completely off the table, but admitted the reintroduction of international travel will throw an inevitable spanner in the works.

“You’re going to have a lot of international travel, and you’re going to have this disease around the world and, really, we might get to 95 per cent (vaccination coverage) but the developing world’s sitting at 10 to 20 per cent, or perhaps even less,” he said.

“So we’re going to have Covid-19 around for a long time. I think the more we can vaccinate our community, the better. We need to look around the world as well at how that’s going.”

When asked why people were being given Pfizer shots as a booster, regardless of their first two vaccine doses, Dr Coatsworth admitted he didn’t believe the science was particularly clear.

“It‘s a really good question. I don’t think there’s a great answer for it,” he said.

State governments are hosting pop-up vaccination clinics at Bunnings stores around the state this weekend to increase access to the COVID-19 vaccine.

Australia has begun its booster rollout scheme, with the nation hitting 80 per cent fully vaccinated on Monday.

“There is some evidence that, if you had AstraZeneca and then you had Pfizer, the mixing and matching of the vaccines might give you a little bit more immunity. But it probably doesn‘t mean that much.

“I do think there might be a reputation component to it now that we’ve got the supply of the mRNA vaccines - people might feel more comfortable getting that as a booster.”

The infectious disease expert said anybody who experienced adverse effects to the mRNA technology, as found in the Pfizer shot, could get an AstraZeneca shot as booster.

“Keep in mind, if you’ve had a problem with an mRNA vaccine, you could equally get the Astra vaccine as your booster, and you’d be fine,” he said.