Computer-designed vaccines confront new flu strains

The researchers − including University of Miami computer scientist Dimitris Papamichail and a team from Stony Brook University, New York − hope to develop the technology and provide an efficient method to confront seasonal epidemics.

The novel approach uses computer algorithms created by Papamichail and Stony Brook scientists to design viruses that serve as live vaccines, which are then synthesised to specification.

Their method is called Synthetic Attenuated Virus Engineering (SAVE).

‘We have been able to produce an entirely novel method to systematically design vaccines using computer algorithms,’ said Papamichail. ‘Our approach is not only useful for influenza; it is also applicable to a wide range of viruses.’

One way to make an anti-viral vaccine is to weaken a virus to the point where it cannot cause sickness and then use it as a live vaccine. Although weakened viruses can make effective vaccines, they suffer from the possibility that the virus can sometimes mutate to regain virulence.

In this study, published online by Nature Biotechnology, the researchers made a synthetic genome of the virus containing hundreds of changes to its genetic code, thereby weakening the influenza virus.

The computer algorithms indicate the best places in the genome to make the changes − such that the new synthetic genome encodes exactly the same proteins as the wild-type genome, but in lesser quantities.

This process allows a wide margin of safety, said Papamichail. ‘The probability of all the changes reverting themselves to produce a virulent strain is extremely unlikely.’

Although the new and original sequences both direct the synthesis of exactly the same proteins, the new sequence gives a weakened version of the virus. For that reason the live vaccine is capable of eliciting an immune reaction against the wild-type virus, but is not strong enough to cause disease symptoms.

This method used to weaken the influenza virus is a general one and may allow the creation of safe, effective vaccines against many different types of viruses.

Looking forward, the researchers would like to explore the applicability of their techniques, with the ultimate goal of methodically and computationally designing synthetic organisms with predetermined functions and controlled properties, with broad applications in medicine.

The findings are available in a study titled ‘Live attenuated influenza virus vaccines by computer-aided rational design,’ published online by Nature Biotechnology.