THIS WEEK THE companies behind one of the Covid-19 vaccine front-runners announced encouraging results from its Phase 3 trial, stating that the vaccine is 90% effective.
Though health officials and politicians have been cautious in their optimism – the full data hasn’t been published, peer reviewed or assessed by regulators yet – they have said it is a positive indication as we head towards the end of 2020.
Following the announcement from Pfizer/BioNTech about their vaccine candidate, European Commission president Ursula von der Leyen said the Commission will authorise a contract for up to 300 million doses.
She described the vaccine as “the most promising so far” out of all the potential vaccines.
The Commission has also reached agreements with three other companies that have a vaccine in development:
England’s chief medical officer this week said he was hopeful the first vaccine could be seen by Christmas. British Prime Minister Boris Johnson has said he expects to have 10 million doses of the Pfizer vaccine by the end of the year if it is authorised by regulators and the NHS has reportedly been told to prepare for mass vaccinations in December.
Health officials and political leaders in Ireland have held back on these kinds of ambitious commitments.
Speaking to RTÉ’s News At One yesterday, Taoiseach Micheál Martin said he believes priority groups will receive a vaccine towards the first half of 2021. He said those who are not considered at high risk will likely have to wait until the middle of the year or later.
“I don’t have precise knowledge on this yet because a lot depends on the clinical trials, coming through the regulatory authorities in Europe and the FDA in the United States, and then you’re into distribution, logistics, manufacturing as well.
Now some of the companies are manufacturing in advance, and Europe has entered into pre-purchase agreements and we’re part of that.”
Earlier this week HSE CEO Paul Reid said health services across the world will face a number of logistical challenges once vaccines are approved for use.
“Glass vials, which are needed for the manufacturing and distribution will be in high demand across the world,” he said.
“Right now there’s a lot of manufacturing processes that will be in high demand. The transportation between ports to storage locations, there will be a mass demand for vehicles and trucks that can have that storage capacity and they’re not widely available.”
He said there is some capacity in large pharmaceutical companies for the type of storage needed for the Pfizer vaccine and others that would need a very low temperature.
The new taskforce which has been established to oversee the rollout of a vaccine will look at all of these issues, he said.
The high-level vaccine taskforce will be tasked with co-ordinating preparations and ensuring the nationwide roll out of a Covid-19 vaccine when one is safe and ready to be distributed.
The group will be chaired by Professor Brian MacCraith, the former president of DCU. Chief Medical Officer Tony Holohan will also be on vaccine taskforce, as will the HSE’s Paul Reid.
Senior civil servant and chair of the senior officials group on Covid-19, Liz Canavan; Barry Lowry, the government chief information officer; and Paul Quinn, the government chief procurement officer, will also sit on the taskforce.
In addition, there will be a nominee yet to be confirmed from the Department of Business, Enterprise and Innovation, who will be a logistics cold chain expert and a project management expert.
This vaccine uses molecules called ‘messenger RNA’ (mRNA) and is a vaccine approach that has never reached approval before.
Many traditional vaccines involve injecting people with a small amount of the virus.
With this new approach, the immune system never has to be exposed to the actual virus. Instead, it makes human cells grow what is know as spike proteins, causing the immune system to produce antibodies against the virus.
The Pfizer/BioNTech Phase 3 study enrolled 43,538 participants, 42% of whom have ‘diverse backgrounds’, according to the companies.
This included participants aged 65 to 85. It said no “serious safety concerns” have been observed. There have been 94 confirmed cases of Covid-19 in trial participants.
Pfizer/BioNTech said the vaccine was found to be more than 90% effective in preventing Covid-19 in participants.
The vaccine, like many of the others currently at Phase 3, require two doses. Clinicians have said this could cause logistical difficulties as it means twice the number of visits to a vaccination centre or wherever it is administered.
At best it could result in resource and administrative challenges in developed countries, but it presents a much more serious barrier for less developed countries.
Another serious roadblock is the temperature at which this vaccine needs to be stored: at -80 degrees.
For temperatures as cold as the Pfizer/BioNTech vaccination requires, dry ice has to be brought into the mix. Currently, the vaccine is shipped in coolers that can be fed with dry ice to keep it frozen for 15 days. After this it can be refrigerated for up to five days before being diluted and injected.
The medical community is already well familiar with the use of the ‘cold chain’ for vaccinations such as flu. But while laboratories have some experience with the use of dry ice, GPs and pharmacists who play a significant role in the vaccination programme do not have this kind of infrastructure. This is an obstacle – but not an insurmountable one.
This vaccine uses a different process to the Pfizer/BioNTech vaccine. It is what’s known as a a non-replicating viral vector vaccine.
Viral vector varieties use other forms of live virus to deliver DNA into human cells, triggering an immune response. A measles virus modified with a coronavirus protein, for example, could be deployed against Covid-19.
It only requires one dose, something that is likely to make it one of the most appealing candidates. The vaccine also does not require the intense cold temperatures needed for mRNA vaccines.
In September, trials on this coronavirus vaccine were paused after a UK volunteer developed an unexplained illness. British regulators and an independent review concluded the illness was not a side effect of the vaccine.
Last month it was confirmed that a volunteer participating in clinical trials of the vaccine developed by Oxford University had died, but the man had received a placebo, rather than the active vaccine.
The vaccine’s developers have said it produces an immune response in older age groups as well as in younger people. AstraZeneca and Oxford University have said data from their late-stage clinical trials are expected by the end of 2020.
This is also a non-replicating viral vector vaccine. It uses a dose of a cold-causing adenovirus, modified so that it can no longer replicate. This is combined with a part of the new virus, SARS-CoV-2, called the spike protein that it uses to invade human cells.
In October, the trial was paused over safety concerns after one patient became sick. The company has since said no clear cause was identified, but based on “information gathered to date and the input of independent experts”, it found no evidence that the vaccine candidate caused the event.
At the end of last month it said it was preparing to resume Phase 3 of its trial, for which it is enrolling up to 60,000 people across 180 sites. The company said this will include “significant representation from those who are over age 60″.
Pre-clinical testing on rhesus macaque monkeys that were published in the journal Nature showed this vaccine provided complete or near-complete protection against virus infection in the lungs and nose.
French company Sanofi and British firm GlaxoSmithKline’s vaccine candidate is still undergoing Phase 1 and 2 trials, with the first results expected at the end of this month or in early December.
The companies have signed an agreement with Covax, the global inoculation scheme backed by the World Health Organisation, to supply 200 million doses. It has also signed a US deal to supply more than 100 million doses.
This vaccine uses the same approach as one of its seasonal flu vaccines and is combined with a substance which boosts the vaccine.
Sanofi is also working with US company Translate Bio on an mRNA vaccine but this is at an earlier stage.
- With reporting by Christina Finn.
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