Nanogirl Michelle Dickinson: Why does it take so long to make a vaccine

Passengers arrive at Heathrow Airport in London after the last British Airways flight from China touched down following an announcement the airline was suspending flights to and from China. Photo / AP

The whole world is watching as cases of the coronavirus are confirmed around the world. While we wait to see how big a threat the virus is to humans, the race is on to create a vaccine which is months if not years away. So why does take so long?
Vaccines work by helping our immune system to recognise and fight a specific virus by introducing a molecule from them called an antigen. The introduced antigen tricks the body to think it is under a full-blown virus attack, when actually it's just a relatively safe form. The trick triggers our immune system to aggressively fight the antigen before it becomes dangerous and in the process creates antibodies specific to that virus. If the virus returns, the immune system is now trained to remember and attack the virus before it can spread through the body and cause illness.
Back in the day, vaccines were both primitive and dangerous. The initial smallpox vaccine involved ground up smallpox scabs being blown up the noses of healthy people. Mostly this led to the person developing a mild case of the disease which they would recover from leaving them with immunity for the rest of their lives. However, sometimes it would lead to a severe case of the disease which was fatal.
Fatal is never a good outcome for a vaccine which is one of the reasons why the development of a coronavirus will take so long.
The coronavirus got its name because it looks like a solar corona when viewed under an electron microscope. As a family of viruses, strains of coronavirus circulate among many different animals including camels and bats. There are many viruses that circulate in animals that humans don't need to worry about, but this new strain of coronavirus named 2019-nCoV is zoonotic meaning that it has spread to humans from animals. Other zoonotic diseases include HIV, Ebola and H5N1 influenza.
While we are still learning about this virus, a recent paper in the Journal of Medical Virology found that 2019-nCoV was a recombination or a mix of two coronaviruses, one known to infect bats while the origin of the other is still unclear.
To create a vaccine you need a sample of the virus itself. This is part of the hold-up as up until this week the virus only existed in research labs in China. In record speed researchers at the Chinese Centre for Disease Control and Prevention genetically sequenced the virus and shared their data internationally. This collaboration led to a team of scientists in Australia being able to successfully develop the first lab-grown version of the virus outside of China.
Luckily for us, previous vaccine development for closely related viruses including SARS and MERS means that we aren't starting from scratch. Vaccine creation technology has also evolved with and a new DNA and RNA-based vaccine technology means there are now multiple ways to create a new vaccine.
The long part of the vaccine development process is still to come. Even if a new 2019-nCoV vaccine was created overnight, it has to be proven to not only be effective but also safe in humans. This involves vaccinating lab animals with the new vaccine then testing how they respond when exposed to 2019-nCoV virus itself. At its fastest pace this process will take months and needs to be completed well before any clinical trials can be introduced to humans. For now, with no human vaccine in sight, we will have to stick to old-school methods to prevent the spread of viruses – covering our mouths when we sneeze and washing our hands often and well using soap and water.