Microneedle Biodegradable Patch With Fusion Protein : Promising Alternative to Influenza Vaccination

Scientists have developed a microneedle patch for the administration of a booster dose of the flu vaccine. The study was published in the Journal of Controlled Release. The use of microneedle patches for vaccination appears to be the way forward to improve compliance and reduce the need for injections. We recently reported a study published in The Lancet, where a patch containing tiny needles was tested in a clinical trial for the delivery of the influenza vaccine. The approach resulted in the safe delivery of the vaccine, whose effectiveness was maintained. The participants of the study preferred this form of vaccine administration as compared to the injection or intranasal delivery of the vaccine.

Now, in another published study, microneedle patches were tested in mice for the delivery of a booster dose of the influenza vaccine. The microneedle patch consisted of biodegradable material, which makes disposal of the patch easy. As in the patch tested in the earlier study, the needles dissolved after being applied to the skin, thereby releasing the vaccine.

Every vaccine contains a protein of the infecting organism, which stimulates the immune system of the patient to produce protective proteins called antibodies. The antibodies protect the patient against the specific disease. The scientists used a fusion protein (4M2e-tFliC) obtained from four different influenza subtypes in this booster dose. This fusion protein could possibly provide protection against all the four viruses.

In their study on mice, the scientists injected the mice with the conventional inactivated influenza vaccine. This was followed four weeks later by one of the following:

• Injection of the 4M2e-tFliC fusion protein into the muscle
• Application of the patch with the 4M2e-tFliC fusion protein
• Application of a placebo patch without the antigen

The mice were then exposed to the H1N1 and H3N2 influenza viruses to test for the efficacy of the viruses. After 14 days, the researchers found that the vaccine administered as a patch:

• Provided long-term antibody mediated response as compared to the conventional vaccine
• Improved the cellular immune response as compared to the injected fusion protein
• Improved survival in the mice

Thus, the M2e-based vaccines improved the immunity of the mice against the influenza virus. The addition of the booster could result in a faster development of protection against the viral infection.

Influenza is a seasonal infection which can even result in a fatal respiratory infection. The influenza vaccine taken annually provides protection against the infection. Unfortunately, many people do not take the precaution of getting vaccinated regularly and therefore are at a risk of suffering from the infection. Therefore, any innovation to improve the efficacy and convenience of taking the vaccine could help to enhance protection in the community. The above invention is a step forward in that direction.

Reference:

1. Zhu W et al. A boosting skin vaccination with dissolving microneedle patch encapsulating M2e vaccine broadens the protective efficacy of conventional influenza vaccines. Journal of Controlled Release. 2017; 261: 1-9. https://doi.org/10.1016/j.jconrel.2017.06.017

Source-Medindia