Coronavirus vaccine: When will we have one?

Coronavirus is spreading around the world, but there are still no vaccines to protect the body against the disease it causes, Covid-19.

Medical researchers are working hard to change that.

Why is a coronavirus vaccine important?

The virus spreads easily and the majority of the world's population is still vulnerable to it. A vaccine would provide some protection by training people's immune systems to fight the virus so they should not become sick.

This would allow lockdowns to be lifted more safely, and social distancing to be relaxed.

What sort of progress is being made?

Research is happening at breakneck speed. About 80 groups around the world are researching vaccines and some are now entering clinical trials.

• The first human trial for a vaccine was announced last month by scientists in Seattle. Unusually, they are skipping any animal research to test its safety or effectiveness
• Pharmaceutical giants Sanofi and GSK have teamed up to develop a vaccine
• Australian scientists have begun injecting ferrets with two potential vaccines. It is the first comprehensive pre-clinical trial involving animals, and the researchers hope to test humans by the end of April
• University of Oxford researchers are aiming to have a million doses of a vaccine by September, and are starting human trials

However, no-one know how effective any of these vaccines will be.

When will we have a coronavirus vaccine?

A vaccine would normally take years, if not decades, to develop. Researchers hope to achieve the same amount of work in only a few months.

Most experts think a vaccine is likely to become available by mid-2021, about 12-18 months after the new virus, known officially as Sars-CoV-2, first emerged.

That would be a huge scientific feat and there are no guarantees it will work.

Four coronaviruses already circulate in human beings. They cause common cold symptoms and we don't have vaccines for any of them.

What do I need to know about the coronavirus?

What still needs to be done?

Multiple research groups have designed potential vaccines, however, there is much more work to do.

• Trials need to show the vaccine is safe. It would not be useful if it caused more problems than the disease
• Clinical trials will also need to show the vaccine provokes an immune response which would protect people from getting sick
• A way of producing the vaccine on a huge scale must be developed for the billions of potential doses
• Medicines regulators must approve it before it can be given
• Finally there will be the huge logistical challenge of actually inoculating most of the world's population

Lockdowns could make this process slower. If fewer people are infected, it will take longer to know whether a vaccine actually works.

The idea of giving people the vaccine and then deliberately infecting them (known as a challenge study) would give quicker answers, but is seen as too dangerous while there is no known treatment.

How many people need to be vaccinated?

It is hard to know without knowing how effective the vaccine is going to be.

It is thought that 60-70% of people needed to be immune to the virus in order to stop it spreading easily (known as herd immunity).

But that would be billions of people around the world if the vaccine worked perfectly.

• When will the outbreak end and life get back to normal?
• Lockdown: How can we lift restrictions

How do you create a vaccine?

Vaccines harmlessly show viruses or bacteria (or even small parts of them) to the immune system. The body's defences recognise them as an invader and learn how to fight them.

Then if the body is ever exposed for real, it already knows what to do.

The main method of vaccination for decades has been to use the original virus.

The measles, mumps and rubella (MMR) vaccine is made by using weakened viruses that cannot cause a full-blownRead More – Source

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