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3rd December 2020

Relax, the vaccines are here

How do the new COVID-19 vaccines work? Why were they made so quickly? Can we trust them?
Relax, the vaccines are here
[Jernej Furman @ Flickr]

The world has breathed a huge sigh of relief with the emergence of not one, but three effective vaccines against COVID-19. Although vaccination is a science that has been in practice for many years, many people have expressed their concern over the rapid development of these new vaccines.

Can we trust them?

The answer is yes, we can trust them. And the explanations for their speedy development is very simple: every research lab in the world at the moment is receiving more funding than ever with the one goal of creating a vaccine.

If you combine essentially unlimited funding, the focus of all research labs, and thousands of willing volunteers, you get the perfect recipe for producing a quick vaccine.

How were they made so quickly?

Most people think that the longest part of producing a vaccine is the clinical trial and assessing side effects; And whilst this is an essential part, the stage that takes the biggest amount of time actually comes before most of the actual research. In most cases, applying for research, proposals, finding funding, securing grants and other admin protocol is usually the reason why vaccine production seems to take so long.

Finding volunteers is especially difficult in normal circumstances because often, people don’t see the urgency or don’t care enough because it isn’t a cause personal to them. But with COVID-19, every single person on the planet has been affected, and it makes sense that many people want to help to end this pandemic. And a great way to do that is by taking part in vaccine trials!

What goes on during the clinical trials of vaccine development?

The clinical stages of vaccine development are pretty straightforward. The first stage involves testing a small group of volunteers. If no major side effects can be seen then the process carries on to stage two, comparing the effects of the vaccine on two groups: one administered with the vaccine and the other with a placebo. If there are no problems following this, then research can progress into the third and final stage: mass sampling. Essentially the same as stage one but requiring many more volunteers in order to gain a better picture of a larger proportion of the population.

It’s also important that the volunteers – across all stages – are of various ethnicities, gender and age so that the sample is even more reliable as a representation of the entire population. You can now hopefully understand why recruiting as many volunteers as possible is essential to developing a safe and reliable vaccine, and can take a long time.

 Are they effective?

The three current vaccines leading the race against COVID-19 are the Pfizer vaccine, the Moderna vaccine, and the Oxford University/AstraZeneca vaccine, and their effectiveness is 95%, 94.5% and 70.4% respectively.

At first glance, this may seem like the Oxford vaccine is lagging behind the other two, but this is not the case. In fact, for most drugs and vaccines, around 70% is more than sufficient for it to be cleared as valid and made accessible to the public.

For example, take the influenza vaccine. The strain of flu changes frequently, which demands a new vaccine every year. Therefore, on average, the flu vaccine is only about 40% effective. Some years we get it really right, some years less so.

But nonetheless administering the vaccine saves thousands of lives against the flu. So the fact that these new vaccines are 70% and above is actually very promising.

How do the vaccines actually work?

Time for some deeper science!

You may remember from your school days an odd thing or two about vaccines, and that most of them work by injecting a small sample, possibly living or dead, of the disease-causing virus or bacteria, known as the pathogen  so that the body’s natural immune system can recognise it and build up immunity without the need for infection.

This is how the Oxford/AstraZeneca vaccine works too: using a modified version of the virus that is non-infectious.

However, the Moderna and Pfizer vaccines work slightly differently: instead of injecting the virus itself, they insert portions of its mRNA that contain information and instructions for our cells to actually create the virus!

But don’t be alarmed, the mRNA only encodes the essential parts of the virus or enough for the body’s immune system to recognise it as the ‘real thing’, not the nasty parts that make us become sick. So essentially, the vaccine triggers our cells to start making ‘blank’ copies of the virus, which doesn’t make us sick: our immune system can still recognise them to build up immunity.

It’s worth mentioning that the nature of this vaccine also speeds up development because mRNA is faster to produce and  allows researchers to produce non-infectious viruses, so there is less concern surrounding the prospect of accidental infection upon vaccination.

When can I get vaccinated?

Whilst the results are promising, this data is all preliminary, therefore, peer-reviewing is required. According to the BBC, the UK has ordered 100 million doses of the Oxford/AstraZeneca vaccine, but sadly we don’t know when that will all be available for public distribution. What we do know is there will be a staged scheme according to priority of who needs the vaccine first (I.E. age will almost certainly be top of the list, whereas young people will probably go last unless they have underlying health conditions).

But whenever the time comes, I hope I don’t have to be the one to encourage you to go and get vaccinated.

Sam Bronheim

Sam Bronheim

Co-Science Editor

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