Battle of The Boosters: The Newest COVID19 Vaccinations
On the 23rd March 2020, the entirety of the UK was flipped upside down. Schools closed, pubs and restaurants shut down, queues outside of supermarkets, people buying 50+ toilet rolls for… some reason…
There has been a new-found feeling of hope spreading around the UK for the last few weeks, due to the discovery of highly effective vaccines against the SARS-COV-2 virus. But, what are they, and what does this mean for us?
Pfizer (BioNTech)
So first came the Pfizer (BioNTech) vaccine. This is the news that ultimately started a mass Mexican-wave of cheers, relief, and hope across the world.
Vaccines are a way of helping the body to recognise a new micro-organism, and therefore prepare it for when it comes into contact with the real thing. This makes the vaccinated person way less likely to contract the disease, or improve the symptoms to a point where it is no longer dangerous or deadly.
The way that the BioNTech vaccination works, is by injecting some of the SARS-COV-2 virus’ genetic makeup (otherwise known as mRNA) that is used by the virus to make more of itself, into the muscle in the upper arm, the cells in the muscle will start to make one specific viral protein and let them loose inside the body.
This therefore mimics what the SARS-COV-2 virus would do, except in a safer and more controlled way. This is almost like showing your immune system a movie-trailer preview of what contracting SARS-COV-2 is like, and therefore can learn in advance what to do to fight it.
When the announcements came out from Pfizer via a press release, the news spread around the world like a wildfire, with governments across the globe securing millions of doses once it’s approved for use.
Moderna
The Moderna vaccine works in the same way as the BioNTech vaccine. It uses mRNA from SARS-COV-2 to make the body make viral proteins to prepare the immune system for if it comes into contact with the virus.
The vital difference between these two vaccines, is the storage that is required. There are a lot of factors that can make a vaccine difficult to roll out in a country, for example, manufacturing issues and a lack of vials are real problems that mass-vaccination runs into regularly.
However, arguably the most complex hurdle for country-wide vaccination is how easy or difficult it is to store. The BioNTech vaccine has some rather demanding storage requirements: it needs to be stored at -80°C for at most 6 months, and can be bought up to 2°C for a maximum of 5 days before it becomes useless. Just for context, at -80°C skin freezes almost instantly; rubber shatters; and metal can become brittle.
The Moderna vaccine is not as picky, however is still a bit of a pain by vaccination standards. It can be stored for up to 6 months in a regular freezer, so around 20°C; and then can be kept at 2°C for a maximum of 30 days. So not only can this vaccine be stored long-term at a higher temperature and in an every-day appliance, but it can also be kept at fridge temperatures for 25 days longer than the BioNTech vaccine.
Oxford University (AstraZeneca)
A few days after the BioNTech and Moderna mRNA vaccine efficacies were revealed, the Oxford University/AstraZeneca trial announced successes also. This study has not reached the same stages of testing as the other two vaccines, however early results are “encouraging” according to Oxford University researchers.
This type of vaccine is different to the Moderna and BioNTech inoculations — which could be very good news if the encouraging results keep coming.
This vaccine uses a virus (ChAdOx1) that typically causes the common cold in chimpanzees, but is a very similar shape to Coronaviruses. This chimpanzee virus is then genetically modified to become entirely harmless to humans, which makes it even safer to give to young children and anyone with a pre-existing medical condition. By injecting this into the body, the immune system learns to recognise this type of virus, and produce a more efficient immune response when it becomes exposed to similar viruses like SARS-COV-2 in the future. This type of chimpanzee virus vaccination has been studied intensely, and has been used successfully in thousands of people.
The reason this vaccine is so special, is because not only is it safer for children and people with pre-existing medical conditions, but it should be also incredibly easier to store. Previous data surrounding this type of vaccination confirms that these vaccines can be successfully stored at 2°C.
What does this mean?
There are many logistical challenges that go into delivering mass vaccination such as this. Storage being a key factor, as well as materials availability; manufacturing hurdles; delivery speed; as well as choosing priority groups.
With some sources claiming a vaccine could potentially be approved in December 2020, this doesn’t mean you should get your coat on and make your way to the nearest pharmacy. Unless you fall into a priority group such as an elderly person in a care home, a care home worker, or NHS worker, you likely won’t be seeing this vaccine for months to come.
However, there is hope that large portions of the population could potentially receive the first round of vaccinations (it is uncertain so far whether or not booster vaccinations will be required) by late Spring 2021. So, it looks like things will continue to be largely uncertain for a while yet.
By Phoebe Hinton-Sheley