• A Microparticulate Vaccine Microneedle patch for pain-free Immunization against Coronavirus Disease

      Vijayanand, Sharon; Patil, Smital R.; Joshi, Devyani; D'Souza, Martin J. (2021)
      Microneedle (MN) patches for vaccine delivery is an effective immunization strategy suitable for mass immunization. Here, we test the level of immunity provided by a microparticulate (MP) heat-inactivated coronavirus vaccine when administered via the skin as pain-free dissolving MN patches. The vaccine formulation utilizes an MP matrix that provides protection of the antigen and improved antigen uptake by antigen-presenting cells (APCs). The microparticles (MPs) were formulated using a double emulsion method, lyophilized, characterized, and assessed for their in vitro immunogenicity. The in vivo efficacy of the MP vaccine was tested in mice. The immunization was done in 3 doses. ELISA was done to assess the IgG level in mice sera. The animals were sacrificed at week 10 and their organs were harvested for further analysis and expression of immune markers. The results show that the MPs were less than 1 microns in size and the MP vaccine induced a strong innate immune response in vitro. Serum analysis showed higher IgG levels of the vaccine groups. The vaccine groups showed a higher expression of antigen-presenting molecules. Based on the results, we summarize that the MP vaccine can produce an effective immune response when administered as an MN patch via the skin. Moreover, MN patches allow self-administration, which greatly increases patient compliance in addition to decreasing the need for trained pharmacists for immunization.
    • COVID-19 Subunit Vaccine: A novel microparticulate microneedle vaccine using spike S1 protein

      Patil, Smital Rajan; Vijayanand, Sharon; Joshi, Devyani; Gomes, Keegan Braz; Menon, Ipshita, J; D'Souza, Martin J. (2021)
      COVID-19 has affected around 118 million people and caused more than 2 million deaths worldwide. Currently, the Food Drug Administration (FDA) authorized vaccines such as Pfizer for COVID-19 require cold chain storage, thus their availability in developing countries is challenging. Microparticles (MPs) are suitable delivery vehicles for vaccine antigens as they are better taken up by antigen-presenting cells, and they eliminate the need for cold chain storage. The spike S1 protein is a suitable antigen candidate due to its ability to produce a robust immune response. For this study, the spike protein was loaded into poly (lactic-co-glycolic acid) (PLGA) MPs and then incorporated into dissolving microneedles, a promising delivery system for large molecules such as proteins. The microparticles were characterized and assessed for innate and adaptive immune response in vitro. The vaccine particles induced a significantly higher nitrite production in mammalian cells compared to control groups. They also exhibited significantly higher expression of antigen-presenting molecules: major histocompatibility complex (MHC) I, CD80, MHC II, and CD40 on the surface of the dendritic cells. This formulated vaccine thus shows high immunogenicity in vitro and has the potential to produce a robust immune response in a murine model, conferring long-lasting protection against coronavirus. This has the potential to be a promising vaccine in the ongoing COVID-19 pandemic the world is facing currently.