These are all the steps normally taken to create a safe and working vaccine.

It usually takes at least a decade to complete them all, but with co vid, they've all been done in less than a year.

So, as is the case with all medicines, a vaccine goes through extensive and rigorous testing before it could be approved and rolled out to a country's population.

For any testing happens in humans, the vaccine is tested on animals in a laboratory.

In the case of covert, 19 ferrets, mice and monkeys have all been used.

That's because they're similar to humans in their physiology and biology.

If the vaccine works and is safe for animals, clinical trials begin.

Phase one trials involved giving the vaccine to a small number of healthy volunteers between 20 and 50 people.

Here, they're looking at safety check.

It generates an immune response on to determine the correct dosage.

Phase two trials involves several 100 volunteers on look at how effective a vaccine is in humans.

This group involves adults of all ages and sexes and, ideally, all ethnicities.

Phase three trials are similar to phase two, but they involve several 1000 volunteers.

They're still looking at how effective the vaccine is, but on a much broader scale.

Usually, these clinical trials run one after another, with time given for the data on how safe, effective and stable the vaccine is to be looked at, and to make a decision about whether the trial should progress to the next stage.

But because of the seriousness of the cove in 19 pandemic, thes phases sometimes overlapped.

Some were even merged Buttle.

The checks that would normally happen was still being done.

Countries have been so keen to find solutions that money has been thrown at organizations to recruit more.

Scientists toe work around the clock on to hire more staff to help find volunteers more quickly.

Because covert 19 has been so widespread, finding volunteers to test the vaccine on has been easier than in other trials.

When enough data has been gathered, it's submitted to a country's regulators for approval.

Scientific and clinical experts review it to see how effective the vaccine is, how safe it is, how stable it is it's quality and check that is being manufactured and stored in a way that meets safety standards on public health policy in the U.

K.

This is the job of the Ciara, the Commission on Human Medicines and even members.

The public are asked what they think.

Normally, this happens after all, the trials have ended.

But in the case of Covert 19, the U.

K's regulatory body was being given data as the trials went along.

This is called a rolling review.

If the vaccine is then approved, it could be given to a wider population.

But the regulators keep monitoring health records on data on anyone who gets one the same as for any vaccine or medicine on every batch.

The vaccine that is made is checked for purity and quality before it's sent anywhere.