Vaccines have saved millions of lives worldwide. They banished smallpox from the face of the Earth in 1980, and other diseases like polio or malaria are going the same way. However, there are diseases that resist vaccination effects. One of these cases is Mycoplasma infections.
Mycoplasma are microorganisms that, although they also infect humans, are famous for infecting pets and farm animals. When they infect poultry, cows and pigs, they cause millions of € in losses both in the EU and USA. Not because they kill the animals, but because of the delay in their growth and their expensive treatment with antibiotics. This not only raises the costs of raising cattle, but adds to the problem of using antibiotics in animals.

Comparison on growth times between healthy and infected poultry | Mycosynvac

In this situation, developing a vaccine that would prevent the infection in the first place would improve both the living conditions of the animals, alleviating their suffering, and save money for the industry. But developing vaccines is never easy. Each microorganism requires its own vaccine, and each one of them presents different challenges. In the case of VIH vaccines, the virus mutates a lot, so it’s difficult to make the immune system recognise a virus that keeps changing. Historically, developing Ebola vaccines was difficult, due to the impossibility to test efficacy in humans, because of the virulence of the virus. In the case of vaccines for mycoplasma infections, some have been developed, but they are costly and not valid for every type of Mycoplasma. The effective vaccines that are available are effective against M. hyopneumoniae in pigs and M. gallisepticum and M. synoviae in poultry. But the production processes of the vaccines is challenging since they involve growing these microorganisms in a complex media that includes animal serum.
That’s why the European project Mycosynvac is trying a whole new approach to developing a vaccine against Mycoplasma infections: using synthetic biology. Their main goal is to design a universal Mycoplasma chassis that they can use as a cornerstone to build vaccines for different types of Mycoplasma. Since they have the smallest genome of all bacteria, it makes it easier to build the simplest version possible, developing a well-equipped genetic toolset in the process, specialised on Mycoplasma.
Once this chassis is developed, they aim to develop attenuated and/or inactivated vaccines against two Mycoplasma pathogens: M. hyopneumoniae (that affects pigs) and M. bovis (affecting cattle). The way to do this is interfering with the molecules Mycoplasma use to attach themselves to animal cells and infect them. These molecules are called adhesins and are very specific: they adhere themselves only to certain type of cells. So researchers from Mycosynvac target the genome responsible for producing these adhesins and modify it. Then they insert this edited genome into the chassis.
The mix from the Mycoplasma chassis and the modified adhesin genome is a good starting point for a vaccine: it is a weakened version of the infectious mycoplasma, and it doesn’t infect cells since it doesn’t have the adhesins necessary to adhere to them. And so, these modified organisms would stay in the bloodstream once administered, serving as training organisms for the immune system, that would get rid of them, and be able to recognise future Mycoplasma invasions once they happen.
Hopefully, developments like this will help create a new wave of vaccines that help us fight more diseases, and bring new tools to those that are already on the way towards eradication. Synthetic biology is a powerful set of tools that can be applied virtually to any field, and Mycosynvac is proof of that. It finishes on March 2020, and we cannot wait to see the final results!