“Tiny capsules engineered to mimic part of the body’s immune system could strengthen its response to vaccines,” reported the BBC today.
The body’s immune response to a vaccine allows the immune system to learn about potential infections such as the flu, allowing it to prepare defences against genuine infections it encounters further down the line.
The news is based on new vaccine research in which scientists were able to synthetically mimic tiny particles released by certain immune cells when they encounter infections and potential threats.
The scientists theorised that these synthetic particles might improve vaccines by the boosting the immune response, and set about testing the theory in mice. The researchers gave the mice a combination of flu vaccine and the synthetic particles. They found the mice produced a greater number and range of ‘antibodies’ (proteins that help identify and fight specific infections). When mice were exposed to the flu, more of the mice who received the particles in combination with the vaccine survived, compared to those who received the vaccine alone.
This exciting technology may have the potential to boost the effectiveness of vaccinations, especially as the researchers were able to vary the synthetic particles, changing the immune response. By combining particular synthetic particles with different vaccinations, the body could be primed to produce the ideal immune response to a particular threat.
However, the research is at an early stage and so far experiments have only been performed on mice. Further laboratory research would need to be carried out before considering any trials in humans to see whether it would be safe and effective to add synthetic particles to vaccines.
Where did the story come from?
The study was carried out by researchers from Duke University in the US and Duke-National University of Singapore. It was funded by the US National Institutes of Health. The study was published in the peer-reviewed journal Nature Materials.
The story was clearly and accurately covered by the BBC.
What kind of research was this?
This was a laboratory- and animal-based study looking at the use of synthetic particles modelled on those released by mast cells, part of the body’s immune system. The particles were also mixed with a flu vaccine administered to mice, to see whether it improved their immune response to the virus. A substance added to a vaccine to boost its potency is known as an adjuvant.
The design of this study is ideal for this type of preliminary research. Further laboratory research would need to be conducted before scientists could attempt any safety and effectiveness trials involving adding synthetic particles to human vaccines.
What did the research involve?
The researchers initially attempted to make synthetic particles, modelled on the particles released by activated mast cells. Mast cells are part of the immune system and play a key role in the inflammatory process.
The researchers injected the synthetic particles into mice, to see whether they behaved in a similar manner to the particles released by activated mast cells. They then tested the immune response after the synthetic particles were given in combination with the flu vaccine. Finally, the researchers varied the composition of the particles, to see whether they could induce the immune response to react in a certain way.
What were the basic results?
The researchers were able to successfully produce synthetic particles that behaved in a similar manner to the particles released by activated mast cells. When the particles were given in combination with the flu vaccine, a greater number and variety of highly specific antibodies were produced compared to when the flu vaccine was given alone. When the mice were then exposed to flu, more of those given the synthetic particles plus the vaccine survived.
Finally, the researchers found that they could influence the type of immune response produced by varying the composition of the particles to make them less like the particles normally released by mast cells.
How did the researchers interpret the results?
The researchers conclude that this technology has the potential to allow the development of precise combinations of synthetic particles and vaccines. The addition of these synthetic adjuvants could improve the effectiveness of vaccines.
In this study, scientists developed tiny particles modelled on those released by a type of immune cell, called a mast cell. When the synthetic particles made by the scientists were given to mice in combination with the flu vaccine, the particles enhanced the number and variety of antibodies made compared to when the flu vaccine was given alone. When the mice were then exposed to flu, more of the mice who received the particles in combination with vaccine survived.
This exciting technology may have the potential to boost the effectiveness of vaccinations. However, so far, experiments have only been performed on mice. Further laboratory research would need to be conducted before considering any trials in humans to see whether it would be safe and effective to add synthetic particles to vaccines.
For example, aside from the checks and testing that must be performed during laboratory development, there are other key issues that would need to be addressed further down the line:
- Does the addition of these adjuvants prevent cases of the disease being vaccinated against?
- Does the addition of these adjuvants reduce the severity of cases?
- Does the addition of these adjuvants prevent deaths related to the disease being vaccinated against?
- Does the addition of adjuvants produce unacceptable side effects?
- Does the addition of these adjuvants affect factors such as the shelf-life of a vaccine?
These types of considerations demonstrate just some of the issues that need to be addressed. Despite the potential this technology holds, it will take further time and research to see if these synthetic particles can be added to vaccines.
- St. John AL, Chan CY, Staats HF et al. Synthetic mast-cell granules as adjuvants to promote and polarize immunity in lymph nodes. Nature Materials, Published online January 22 2012