Washington | MIT scientists, including one of Indian origin, have developed a new easily customisable vaccine that can be rapidly deployed in response to disease outbreaks such as Ebola and H1N1 influenza.
The vaccine, that can be manufactured in one week, consists of strands of genetic material known as messenger RNA, which can be designed to code for any viral, bacterial, or parasitic protein, researchers said. These are then packaged into a molecule that delivers the RNA into cells, where it is translated into proteins that provoke an immune response from the host, they said.
In addition to targeting infectious diseases, researchers are using this approach to create cancer vaccines that would teach the immune system to recognise and destroy tumours. This nanoformulation approach allows us to make vaccines against new diseases in only seven days, allowing the potential to deal with sudden outbreaks or make rapid modifications and improvements, said Daniel Anderson from Massachusetts Institute of Technology (MIT) in the US.
RNA vaccines are appealing because they induce host cells to produce many copies of the proteins they encode, which provokes a stronger immune reaction than if the proteins were given on their own, researchers said.
The idea of using messenger RNA molecules as vaccines has been around for about 30 years, but one of the major obstacles has been finding a safe and effective way to deliver them, they said. Researchers including Jasdave Chahal and Omar Khan from MIT customised RNA sequences, which enabled them to produce nearly any protein they want.
The RNA molecules also include instructions for amplification of the RNA, so that the cell will produce even more of the protein. The vaccine is designed to be delivered by intramuscular injection, making it easy to administer. Once the particles get into cells, the RNA is translated into proteins that are released and stimulate the immune system, researchers said.
The vaccines were able to stimulate both arms of the immune system a T cell response and an antibody response. In tests in mice, those that received a single dose of one of the vaccines showed no symptoms following exposure to the real pathogen – Ebola, H1N1 influenza, or Toxoplasma gondii, researchers said.
No matter what antigen we picked, we were able to drive the full antibody and T cell responses, said Khan. Researchers also believe that their vaccines would be safer than DNA vaccines, another alternative that scientists are pursuing, because unlike DNA, RNA cannot be integrated into the host genome and cause mutations.
Typically a vaccine becomes available long after the outbreak is over. We think we can become interventional over the course of a real outbreak, said Chahal.
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