The existence of the COVID-19 pandemic has made mRNA vaccines one of the prevention modalities during this pandemic. For many scientists, understanding mRNA vaccines is important to know. The mRNA vaccine is not only used for the prevention of infectious disease, but its role in cancer management is well known. The vaccine was developed based on the ability of mRNA to transmit nanoparticles. mRNA delivery nanoparticles are more and more common today.
In addition to the COVID-19 vaccine, various mRNA vaccines are currently in the research stage with various target diseases, namely infections, such as influenza, rabies, Zika, Ebola, Human Immunodeficiency Virus (HIV), dengue, cancer, such as melanoma, cancer. lung, pancreatic, and colon cancer. As a new technology, the mechanism of action of mRNA needs to be studied further by clinicians.
mRNA vaccine development
There are two types of mRNA vaccines, namely conventional mRNA vaccines and self-amplifying mRNA vaccines. Conventional mRNA vaccines contain an mRNA genome that is similar to the parent cell’s mRNA molecule and only encodes the desired antigen. Conventional mRNA vaccines have the advantage of being simple and economical in their production and administration. On the other hand, self-amplifying mRNA vaccines contain engineered mRNA genomes, such as positive-sense single-stranded mRNA molecules obtained from alphaviruses. These mRNAs can self-replicate without producing infectious virus particles, also known as replicons, so they can express large amounts of antigen due to the amplification of these mRNAs in host cells. This gives the self-amplifying mRNA vaccine the ability to stimulate the production of large amounts of antigen at very small doses.
mRNA stabilization improves delivery to individuals
Along with the development of vaccine technology, various efforts to optimize the pharmacology of mRNA vaccines continue to be made to increase their efficacy. Increased stabilization of mRNA and protein translation was achieved by adding structural analogs and synthetic cap enzymes, adding regulatory elements to certain untranslated regions, and increasing poly(A) tail lengths.
Improvement of the immunomodulation profile of mRNA vaccines was achieved by nucleoside modification, refinement of in vitro transcribed mRNA purification techniques with RNase III processing and fast protein liquid chromatography, and optimization of RNA codons and sequences. In addition, improvements to the delivery and administration of mRNA vaccines were also carried out to increase vaccine efficiency.
Advantages and disadvantages of mRNA vaccines
The mRNA vaccine has its advantages and disadvantages when compared to other types of vaccines. The mRNA vaccine can stimulate a good immune system because of its ability to mimic the nature of the intact pathogen without causing complications that can be caused by the presence of the intact pathogen. mRNA vaccines are produced by in vitro reactions between recombinant enzymes, ribonucleotide triphosphates, and DNA templates, so the production of mRNA vaccines tends to be simpler and faster when compared to whole-pathogen vaccines and subunit vaccines.
In addition, the production of mRNA vaccines does not require cultures of pathogens that can be contaminated, so the general risk in vaccines containing intact pathogens or their subunits is avoided. The rapid production of mRNA vaccines also provides a narrow gap for contamination by other microorganisms, so that their safety can be guaranteed. On the other hand, there are several possible drawbacks of mRNA vaccines, such as instability, low immunogenicity, increased risk of autoimmunity, and the need for freezing temperatures in distribution.
To date, no mRNA vaccine has been approved for use in humans, except for the COVID-19 mRNA vaccine. However, in the last two decades, research on the use of mRNA vaccines in disease control, both as the prevention and management of infectious diseases, as well as the prevention and treatment of cancer.
When clinical trials of mRNA vaccines on these two functions are compared, clinical trials of mRNA vaccines in infectious disease control are still at an early stage. The mRNA vaccine is expected to be able to answer the shortcomings of conventional vaccines in handling more challenging viral infections, such as HIV, herpes simplex virus, and respiratory syncytial virus (RSV). The possibility of rapid production can also meet the need for vaccines against the rapid emergence of acute viral infectious diseases, such as the Ebola and Zika outbreaks, as well as the COVID-19 pandemic.
