17 Dec 2020

Covid-19: Big challenge of vaccinating New Zealand is scale - microbiologist

5:12 pm on 17 December 2020

The government making a deal to purchase two more brands of Covid-19 vaccines is proof of good progress, a clinical microbiologist says.

University of Otago professor of infectious diseases David Murdoch.

David Murdoch. Photo: University of Otago

University of Otago professor David Murdoch is a clinical microbiologist who was consulted for the WHO and the Health's Ministry Covid-19 Technical Advisory Group.

He told Nine to Noon the announcement of the new vaccines showed good progress.

"This is a very complex programme that's been set up - the biggest every immunisation for the country. So it is interesting seeing the extra detail, really filling in a few gaps. We now have four vaccines in the portfolio which are different; have different technologies; there's a greater number than the population. There's some options if some don't prove to be successful."

A total of 7.6 million doses will come from AstraZeneca - enough for 3.8 million people, and 10.72 million doses from Novavax - enough for 5.36 million people. Both vaccines require two doses to be administered.

The government already has to pre-purchase agreements for 750,000 courses from Pfizer/BioNTech and 5 million from Janssen.

Murdoch said it was a balanced portfolio and the timeline of it being made available mid-2021 was not too bad.

He reiterated the World Health Organisation's advice that higher-income countries should go through its Covax Facility to guarantee equity for all countries.

He said the Pfizer vaccine would be "more challenging" logistically because it needed to be stored at -70C; the other vaccines can be stored at the usual fridge temperatures.

"The freezers have been purchased ... if they are strategically located, that can be overcome."

"The big challenge of course is the scale."

He said there would need to be a number of vaccinators on the ground.

Portfolio of vaccines welcomed

Microbiologist Dr Siouxsie Wiles told Afternoons with Jesse Mulligan the announcement was great news.

She said some of the technologies used within the portfolio of vaccines would be good for some people, but not others, while some will be more acceptable to some communities than others.

One vaccine announced today is a protein vaccine which means taking bits of the virus and injecting that and another is a viral vector vaccine which means taking bits of another virus and engineering it with the proteins of the coronavirus.

"There will be some people who are uncomfortable with that sort of technology I think."

Dr Wiles said it was appropriate that New Zealand was donating $10 million to the Covax programme that is trying to ensure an equitable distribution of Covid-19 vaccines worldwide.

It was important to acquire vaccines not just for New Zealand citizens but also Pacific neighbours "because one of the things we're seeing in this pandemic is that rich countries are basically taking everything alnd leaving other countries with nothing and frankly that's just not good enough".

"Basically none of us are safe until all of us are safe, so a great result."

MedSafe authorisation is required before any vaccines can be approved, however the process is being sped up by all the data about each vaccine being passed on as it is accumulated rather than waiting until the end of trials.

Dr Wiles said vaccinating all New Zealanders will be a massive logistical exercise, but planning and training is already under way on the rollout and it will be important to gather data on aspects such as any bad reactions.

Meanwhile, vaccinologist Helen Petousis Harris is optimistic the government can avoid past immunisation mistakes when it comes to the Covid vaccine.

Dr Harris has been critical of vaccine rollouts in the past, especially the inadequate process during last year's measles outbreak.

She said this year's effort was already better organised, with a lot of experts having their say and detailed logistics planning already under way.

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