Coronavirus: How close are we to a vaccine or drug?

Coronavirus is spreading around the world, but there are still no drugs that can kill the virus or vaccines that can protect against it.

So how far are we from these life-saving medicines?

There are more than 20 vaccines in development. One has begun human trials after unusually skipping any animal research to test either the safety or the effectiveness of the vaccine.

Other scientists are at the animal research stage and hope to get the results of human trials later in the year.

But even if scientists can celebrate having developed a vaccine this year, there is still the massive job of being able to mass-produce it. It means, realistically, one would not be ready until at least the middle of next year.

All of this is happening on an unprecedented timescale and using new approaches to vaccines, so there are no guarantees everything will go smoothly.

Remember there are four coronaviruses that already circulate in human beings. They cause the common cold, and we don't have vaccines for any of them.

Would it protect people of all ages?

It will, almost inevitably, be less successful in older people. This is not because of the vaccine itself, but aged immune systems do not respond as well to immunisation. We see this every year with the flu jab.

Will there be side effects?

All medicines, even common pain-killers, have side effects. But without clinical trials it is impossible to know what the side effects of an experimental vaccine may be. This is something on which regulators will want to keep a close eye.

Who would get a vaccine?

If a vaccine is developed then there will be a limited supply, at least in the early stages so it will be important to prioritise. Healthcare workers who come into contact with Covid-19 patients would be at the top of the list. The disease is most deadly in older people so they would be a priority if the vaccine was effective in this age group. However, it might be better to vaccinate those who live with or care for the elderly instead.

What about drugs?

Doctors are testing current anti-viral drugs to see if they work against coronavirus. This speeds up research as they are known to be safe to give to people.

Trials are taking place in hospitals in affected countries, but, in February, Dr Bruce Aylward from the World Health Organization, said: "There's only one drug right now that we think may have real efficacy and that's remdesivir."

It was developed as an Ebola drug, but also seems to be able to kill a wide variety of viruses. However, we are still waiting on trial results.

There was much hope a pair of HIV drugs (lopinavir and ritonavir) would be effective, but the trial data is disappointing.

They did

not

improve recovery, reduce deaths or lower levels of the coronavirus in patients with serious Covid-19. However, as the trial was conducted in extremely sick patients (nearly a quarter died) it may have been too late in the infection for the drugs to work.

There is also much interest in an old and cheap anti-malarial drug called chloroquine. Laboratory tests have shown it can kill the virus, but once again we are waiting for results when it is given to patients. Trials are taking place in the US and other countries.

Until a vaccine or treatment is ready what can I do?

Vaccines prevent infections and the best way of doing that at the moment is good hygiene.

If you are infected by coronavirus, then for most people it would be mild and can be treated at home with bed-rest, paracetamol and plenty of fluids. Some patients may develop more severe disease and need hospital treatment.

How do you vaccine?

create a

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 then learn how to fight it.

Then if the body is ever exposed for real, it already knows how to fight the infection.

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 versions of those viruses that cannot cause a full-blown infection. The seasonal flu jab is made by taking the main strains of flu doing the rounds and completely disabling them.

The work on a new coronavirus vaccine is using newer, and less tested, approaches called "plug and play" vaccines. Because we know the genetic code of the new coronavirus, Sars-CoV-2, we now have the complete blueprint for building that virus.

Some vaccine scientists are lifting small sections of the coronavirus's genetic code and putting it into other, completely harmless, viruses.

Now you can "infect" someone with the harmless bug and in theory give some immunity against infection.

Other groups are using pieces of raw genetic code (either DNA or RNA depending on the approach) which, once injected into the body, should start producing bits of viral proteins which the immune system again can learn to fight.