The news that a workable Covid-19 vaccine could be ready as soon as next month – and that life could return to some semblance of normal by next spring – has buoyed spirits.

It comes after one particular vaccine, produced by Pfizer and German biotech company BioNTech, made headlines as initial trials found it to be more than 90% effective in preventing Covid-19.

It’s one of 11 vaccines worldwide which has reached phase III trials – the final stage trials where tens of thousands of people are vaccinated to confirm how safe a vaccine is and how well it works.

The UK government has confirmed it’s already put an order in for the Pfizer/BioNTech vaccine and Matt Hancock has vowed that the NHS is poised to offer a vaccine to the British public, “as fast as safely possible”.

So what do you need to know about the vaccine? We’ll walk you through what we know so far.

1. How it works

It’s an mRNA vaccine, so it uses a bit of the coronavirus’ genetic code to prompt the body to initiate an immune response. 

While many standard vaccines work by injecting a dead or weakened form of a virus into the body in order to build immunity, RNA vaccines introduce a messenger RNA (mRNA) sequence into the body that contains the genetic instructions for the vaccinated person’s own cells to produce the vaccine antigens and generate an immune response.

It’s a bit like injecting an instruction manual so your body is able to build a bit of the virus protein, which then prompts an immune response. The body then knows how to fight the virus if you come into contact with it in real life. Clever.

The benefit of this particular vaccine is because the RNA is man-made, you don’t need live virus to make a batch of the vaccine. This makes it generally easier to manufacture, which could also mean deployment of the vaccine is faster – and cheaper.

2. Who came up with the idea?

A married couple of Turkish descent are the brains behind the vaccine. Professor Ugur Sahin, 55, and Dr Ozlem Tureci, 53, run German biotech company BioNTech.

Their company primarily specialises in individualised cancer medicine, but in January they pivoted to creating mRNA-based viral vaccines to help fight Covid-19, Sky News reported.

3. How successful is it?

So far, in phase III trials, 43,538 participants were injected with the vaccine – 42% of participants came from diverse backgrounds – and the vaccine was found to be more than 90% effective in preventing Covid-19 in participants.

Of the tens of thousands of participants injected, there were 94 confirmed cases of Covid-19. The trial will now continue until a total of 164 Covid-19 cases are detected.

The vaccine is given in two doses, and protection from the vaccine is achieved 28 days after the first injection. But as it stands we don’t know if having the vaccine can prevent Covid-19 transmission to another individual. Nor do we know how long the vaccine would offer protection for. 

4. Is it safe?

While no Covid-19 vaccine has yet been approved for widespread use globally – and has therefore been proven to be safe – we do know that the Pfizer vaccine hasn’t caused any major safety concerns so far.

An external, independent Data Monitoring Committee (DMC) recommended the vaccine trial continues to collect additional safety and efficacy data, which will then be discussed with regulatory authorities worldwide. 

5. Are there any downsides we know of?

One of the biggest issues is that the vaccine needs to be stored at an incredibly cold temperature (reports suggest -70°C/-80°C) in order to work, which standard cold storage and transport used for frozen goods cannot achieve.

This might make global distribution difficult.

6. What happens to other vaccines now?

It’s still a race to the finish line and trials of other vaccines are still going ahead around the world – based on results of trials so far, it’s likely there’ll be a few approved vaccines circulating by this time next year.

7. So when will a vaccine be ready to use?

We still don’t know. Lots more needs to be done in terms of obtaining regulatory approval for these vaccines – and then, of course, they need to be delivered to priority patients first, before being rolled out elsewhere. 

The NHS is currently preparing to deliver a Covid-19 vaccine from as early as next month, according to Simon Stevens, the chief executive of NHS England.

But scientists are increasingly cautious about saying any meaningful change will happen in 2020. Professor Eleanor Riley, an expert in immunology and infectious disease at the University of Edinburgh, said: “With the best will in the world, this vaccine – or any other vaccine currently in trials – isn’t going to change things for the majority of us this winter.”

She pointed out that if we can start vaccinating the elderly and vulnerable, as well as NHS and care home staff, before the end of the year at the very earliest, it will still take time to roll it out to enough people to substantially reduce the pool of highly vulnerable people. 

“Also, this vaccine needs two doses, three weeks apart and it will take at least a week after the second vaccination before you are fully protected,” she added. “So even if you were vaccinated on one day, you couldn’t be confident you were immune for at least a month after that.”

Prof Riley said we “all need to accept” that the current public health measures are going to remain in place “at least until the end of the winter, possibly longer”.

On a brighter note, she added: “If this vaccine lives up to this early promise, and other vaccines work equally well, we may be able to look forward to a much better summer and autumn in 2021.”