Coronavirus is continuing to spread around the world, but there are still no vaccines to protect the body against the disease it causes, COVID-19.
Developing a vaccine is a complex and lengthy process. Research involves organisations including pharmaceutical giants, smaller biotechnology companies, academic centres and non-profit groups.
With over 3 million cases and more than 200,000 fatalities as a result of the coronavirus worldwide (as of April 29), experts are working hard to develop a vaccine that will help curtail this pandemic.
Vaccines often take years of testing to secure a safe and effective product that is suitable for wide scale use on humans.
Why is a coronavirus vaccine important?
The SARS-CoV-2 virus spreads easily and the vast majority of the world's population remains vulnerable to infection. 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 strict lockdowns and quarantine measures to be lifted more safely, and social distancing to be relaxed.
Developing the new coronavirus vaccine
Under WHO’s direction, a group of international experts are working towards the development of vaccines against COVID-19.
Experts include scientists, physicians, funders and manufacturers who have come together as part of an international collaboration coordinated by WHO to help accelerate the availability of a vaccine against COVID-19.
The first human trial for a vaccine was announced last month by scientists in Seattle. Taking an unusual decision, the team deviated from the normal vaccine development process, by skipping any animal research to test its safety or effectiveness.
The biotechnology company CanSino (China) has an experimental vaccine and is now in phase two of human trials.
Inovio Pharmaceuticals and Moderna, based in the United States, have also started human trials.
The typical process for vaccine development involves laboratory testing, followed by clinical trials on animals. Vaccines are usually tested on a small group of human volunteers before they are trialled on larger numbers.
Australian scientists have begun injecting ferrets with two potential vaccines. This is the first comprehensive pre-clinical trial involving animals. The experts hope the vaccine will be ready for human trials by the end of April.
In Oxford, the first human trial in Europe began on April 23, starting with two volunteers. They are the first of more than 800 volunteers recruited for this study.
Half will be injected with COVID-19 vaccine, and the other half, with a control vaccine which protects against meningitis but not coronavirus.
The vaccine was developed in under three months by a team at the University of Oxford. Sarah Gilbert, professor of vaccinology at the Jenner Institute, led the pre-clinical research.
"Personally I have a high degree of confidence in this vaccine," said Professor Gilbert.
Some experts are concerned that as pressure to create a vaccine as quickly continues to mount, some vital steps in traditional vaccine development processes may be being missed.
This scenario can lead to "immune enhancement" (sometimes also known as "disease enhancement"), which means the vaccine weakens a person's immune response to the virus as opposed to preventing infection.
"The way to reduce the risk of immune enhancement is to firstly demonstrate this doesn't happen in laboratory animals," Peter Hotez, dean of the National School of Tropical Medicine at Baylor College of Medicine, told Reuters.
The director of the U.S. National Institute of Allergy and Infectious Diseases, Anthony Fauci, said the United States will have to wait 12 to 18 months at the earliest for a coronavirus vaccine. Some experts have warned that even trying to meet that deadline is a risky plan that could backfire.
The effectiveness of any of the vaccines in development for COVID-19 still remains unknown.