The development of an effective HIV vaccine has been ongoing. HIV sequence diversity and immunodominance are major obstacles in the design of an effective vaccine. Researchers at the National Cancer Institute (NCI) developed a novel vaccine strategy combining both DNA and mRNA vaccination to induce an effective immune response. This combination strategy could also be used to develop vaccines against cancer or other infectious diseases (ex. SARS-CoV-2).
Vaccines have become one of the most important tools in the fight against cancers and infectious diseases. However, some vaccines have shown limitations due to their high cost and low immune responses. To overcome these limitations, bacteriophages were proposed for the development of more cost-effective, immunogenic vaccines. Phages have shown a strong ability to activate induced and adaptive immune systems. The genome of these viral particles can be engineered, and their surface proteins can be exploited for antigen display.
The Corona virus disease, 2019 (COVID-19) pandemic is a worldwide public health crisis with over 153 million confirmed cases and 3.2 million deaths as of April 2021. COVID-19 is caused by a novel coronavirus called SARS-CoV-2. SARS-COV-2 infects hosts via its spike (S) protein, which has two portions, S1 that binds the cell and S2 that is involved in viral entry via fusion with the cell membrane. There are several vaccines available for COVID-19 patients that directly target SARS-CoV-2 by systemic immunization.
Human immunodeficiency virus (HIV) infections remain a pandemic, most prevalent in Africa and the Americas. Anti-retroviral treatments have been effective in preventing spread of the virus and active outbreaks of acquired immune deficiency syndrome (AIDS). However, the development and deployment of an effective vaccine would provide long-lasting protection and alleviate the need to depend heavily on prevention methods that require continued access and adherence.
Vaccines against non-viral cancers target mainly differentiation antigens, cancer testis antigens, and overexpressed antigens. One common feature to these antigens is their presence in central immunological tolerance. Using these vaccines, T cells underwent depletion of high avidity clones directed against such antigens. This depletion can cause the loss of T cells bearing high affinity T cell receptors (TCRs) for their cognate antigens which have superior cytotoxic capacity, longer persistence in the tumor microenvironment, and decreased susceptibility to immune suppression.
The development of an effective HIV vaccine has been an ongoing area of research. High variability in HIV-1 virus strains, however, represents a major challenge. Ideally, an effective candidate vaccine would provide protection against the majority of clades of HIV. Two major hurdles to overcome are immunodominance and sequence diversity. Researchers at the National Cancer Institute (NCI) have developed a vaccine that overcomes these major hurdles by utilizing a strategy that identifies conserved regions of the virus and exploits them for use in a targeted therapy.