New Zealand has agreed to buy four Covid-19 vaccines, in volumes that are more than enough for everyone in New Zealand and for some of our Pacific neighbours too. Siouxsie Wiles on what yesterday’s announcement means, and what comes next.
First a quick recap. There are lots of different ways to design a vaccine, which use different technologies and have different advantages and disadvantages. If you need a reminder, check out the vaccine explainer that Toby Morris and I put together below. More details are here. According to the New York Times Covid-19 vaccine tracker, there are currently 17 vaccine candidates in phase 3 clinical trials, five in early limited use, and two that have been approved by a small number of countries.
Why buy more than one vaccine?
For months, many countries have been negotiating pre-purchase agreements with companies to ensure access to the different vaccines under development. New Zealand was no different, and it has now been revealed we have signed pre-purchase agreements to access four different vaccines that have been developed using a range of technologies. This is important because each technology has different advantages and disadvantages, and some vaccines will be more acceptable to some communities than others.
But there is another good reason for signing more than one agreement. When negotiations began, there was no guarantee that all the vaccines would turn out to be safe and effective. Just recently the University of Queensland/CSL vaccine was abandoned when it was found that some vaccinated people tested positive for HIV. They didn’t have HIV, just antibodies that reacted with the HIV test making them false-positives. And that’s really bad. Without treatment, HIV is deadly. To be treated, people need to be diagnosed. And that needs a reliable test – not one that throws up false-positives just because people have been given this vaccine. So the decision was made to abandon the vaccine, and rightly so.
If you are curious how people could end up with HIV-like antibodies after receiving a Covid-19 vaccine, it’s because of the way the University of Queensland researchers designed their vaccine. They created a little clamp to hold the Covid-19 spike protein in the right shape. Unfortunately, that clamp is similar to a protein on HIV, and some people made antibodies to it too.
Which Covid-19 vaccines has New Zealand bought?
We’ve got a similar portfolio to quite a few other countries, including the USA, UK, the European Union, Australia, and Canada. Ours is made up of these four:
Pfizer/BioNTech mRNA vaccine
This is the one that needs storing at minus 70 degrees Celsius and that the UK was the first to grant an emergency use authorisation for. The UK is now vaccinating people with it, as is the USA. It’s also authorised for limited use in Kuwait, Mexico and Singapore. Bahrain, Canada and Saudi Arabia have given it full approval, according to the New York Times vaccine tracker. New Zealand has bought enough for 750,000 people and those doses will start arriving in the first part of next year.
Janssen/Johnson & Johnson viral vector vaccine
This one uses the backbone of a less harmful virus – in this case a human adenovirus – engineered to contain the spike protein from the Covid-19 virus. This vaccine is still in phase 3 trials as both a one-dose and two-dose vaccine. A one-dose vaccine would be a big advantage as you wouldn’t need to get people back a few weeks later for a second dose. Trials of this vaccine were stopped temporarily back in October when someone had what was described as a “serious medical event”, but things are back on after an investigation found no evidence that the vaccine was responsible. We’ve bought enough for 5 million people but don’t expect this one till late next year or even 2022.
University of Oxford/AstraZeneca viral vector vaccine
This one is in everyone else’s portfolio too and is another vaccine that uses the backbone of a less harmful virus – in this case a chimpanzee adenovirus. It’s also in phase 3 trials and we’ve ordered enough of this one to vaccinate 3.8 million people.
Novavax protein subunit vaccine
This one is also in plenty of other portfolios and is still in phase 3 trials. This vaccine just uses the protein from the virus that the immune system needs to recognise, along with what’s called an adjuvant which helps to stimulate the immune system. We’ve ordered enough for 5.36 million people.
Why so many vaccine doses?
If you’ve done the maths, you’ll have realised that all these purchases will vaccinate more than the population of New Zealand. Again, that’s partly because we don’t know if all of them will end up being approved. But we’ve also purchased vaccines for the other countries in the Realm of New Zealand – Tokelau, the Cook Islands, and Niue – and enough to provide for some of our Pacific neighbours if they wanted them. Also in yesterday’s announcement was $75 million earmarked to support Pacific and global vaccine access and roll-out, $10m of which will go towards the COVAX initiative, which is pulling together its own portfolio of vaccines and guarantees fair and equitable access for every country in the world.
When will we get the vaccine?
The prime minister has been very clear that we shouldn’t expect the vaccines to be widely available in New Zealand until the middle of 2021. Trials of some are still ongoing, and there will only be so many doses that the companies can manufacture and deliver. That manufacturing capacity is being challenged by South Africa and India who have called for the World Trade Organisation to suspend Covid-19 related intellectual property rights. That would mean manufacturing isn’t just concentrated in the hands of a small number of patent holders. The challenge is being staunchly opposed by the pharmaceutical industry and many high-income countries. Surprise, surprise.
To be used in New Zealand, any vaccine would also have to be approved by Medsafe. The good news is that Medsafe is accepting rolling submissions of safety and efficacy data rather than it being submitted all at once. That means New Zealanders can be assured that there will be no unnecessary delays in authorising the vaccines should that data prove they are safe and effective.
The big question now is, how safe and effective are the different vaccines? While data on safety looks really good, the scientific community are still waiting to see all of the data for how well each vaccine prevents transmission of the Covid-19 virus as well as preventing severe disease. That will determine how the vaccines should be rolled out in New Zealand and when it will be safe to open our borders again.
That means we’ll be sticking with our Emmental/Swiss cheese model of control measures that have served us so well up till now. So if you aren’t using the Covid Tracer app yet, download it and get started. It just got a Bluetooth upgrade too, so switch that on. And don’t delay asking for a test if you have any symptoms that could be Covid-19.
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