A faster vaccine

CURRENT VACCINE DEVELOPMENT schedules are the stuff of epidemiologist nightmares. Imagine if Ebola or Zika spread near uncontrollably for ten years while scientists tried to create a vaccine that is safe, effective and abundant enough to administer to large groups of people.

Inovio Pharmaceuticals, the drug company behind what looks to become the fastest vaccine ever to come to market, may be able to halt such a spread before it gets out of control. The company shocked the medical world in June by announcing that its Zika vaccine had already received FDA approval for human clinical trials, just nine months after the race to prevent Zika began. If all goes well, its shot will be available to the public as soon as early 2018.

Inovio’s secret is that it’s using a completely new form of vaccination. In first-generation vaccines, a weaker or dead form of the virus triggers your immune system to develop antibodies that could shut down the real virus. Newer vaccines include only outer pieces of the virus – the envelope – that specifically trigger the antibodies. These vaccines are safer, because there’s no way for them to copy themselves until they make you sick, but they can take a long time to create in a lab.

Inovio’s vaccine is a thirdgeneration vaccine, a DNA vaccine. All it contains are DNA instructions to build the virus envelope. “If the Zika virus were a MercedesBenz, we’re just making the front grille. Everyone recognises the three-pointed star as a Mercedes, but it’s not the actual car,” says Dr J Joseph Kim, president and CEO of Inovio. The instructions are made out of simple, readily available chemicals. Once a doctor injects the instructions into your arm, your own cells build the envelope. Then your immune system fights the envelope and you’re safe from the real virus. It’s sort of like outsourcing the work of creating a vaccine to the human body; no long wait times or biohazard suits required.

The virus envelope proteins (red) spur the immune system to make killer T-cells (red and blue) and antibodies (yellow).

Once inside the nucleus, the vaccine tells the body’s own cells to create proteins from the virus envelope.

A DNA vaccine consists of viral DNA and an electrical pulse that pushes that DNA into the cell nucleus.