The key difference between mRNA and adenovirus vaccine is that mRNA vaccines usually consist of a copy of mRNA with a protective chemical shell, while adenovirus vaccine consists of a harmless virus that encodes the virus spike protein.
Vaccines guide the immune system to act against diseases. These help the immune system to develop necessary cells and proteins to fight against pathogens when they come across a disease. Vaccines can be injected into a muscle or can be administered orally. mRNA and adenovirus vaccines both act against respiratory diseases. Either DNA or RNA is delivered to your cells, stimulating the cells to produce pathogen proteins. These proteins induce the immune system to develop resistance to the respective pathogen.
CONTENTS
1. Overview and Key Difference
2. What is an mRNA Vaccine
3. What is an Adenovirus Vaccine
4. Similarities Between mRNA and Adenovirus Vaccine
5. Side by Side Comparison – mRNA vs Adenovirus Vaccine in Tabular Form
6. Summary
What is an mRNA Vaccine?
mRNA vaccine, also known as messenger RNA vaccine, is a type of vaccine that uses a copy of mRNA to produce an immune response. mRNA vaccine is a vaccine targeted against infectious diseases such as influenza virus, Zika virus, rabies virus, Covid 19 and many more. mRNA vaccines are also used against cancer. Dendritic cell vaccines and other types of directly injectable mRNA have been used in cancer clinical trials. mRNA is complementary to one of the DNA strands of a gene. Similar to DNA, the genetic information of mRNA is hidden in a nucleotide sequence.
The mRNA vaccine deliberately introduces synthetic RNA into immunity cells or dendritic cells. Once inside the immune cells, the RNA of the vaccine acts as mRNA. This causes the cells to produce a foreign protein which would normally be produced by a pathogen such as a virus or a cancer cell. These protein molecules stimulate an adaptive immune response. This helps the body to identify and destroy the corresponding pathogen (virus) or cancer cells.
Figure 01: mRNA Vaccine
mRNA vaccines function differently from other vaccines. Vaccines usually stimulate an antibody response by injecting the antigens. These antigens are prepared and grown outside the body. But, mRNA vaccines introduce a short-lived nucleoside-modified mRNA (modRNA) of a virus into the vaccinated individual. modRNA is a synthetically created fragment of the RNA sequence. Since the antigens are produced inside the host cell, it stimulates both cellular and humoral immunity.
What is an Adenovirus Vaccine?
Adenovirus vaccine is a vaccine against adenovirus infection. Adenovirus infection is a common infection in the respiratory system. Moreover, adenovirus is a double-stranded DNA virus. This vaccine shows immunity to adenovirus serotypes 4 and 7. Serotypes are distinct variations between species of bacteria, virus or among immune cells of various individuals. Serotypes 4 and 7 are most commonly associated with respiratory diseases. Adenovirus vaccine is administered orally and consists of live virus. These vaccine tablets are usually coated so that the virus passes through the stomach and infects the intestines. This raises an immune response.
Figure 02 Adenovirus
Adenovirus vaccines are administrated against HIV, Ebola virus, Influenza virus, Covid 19, Mycobacterium tuberculosis and Plasmodium falciparum. These vaccines are produced by inserting a transgene cassette into the adenovirus. This is done by direct cloning or homologous recombination. A transgene cassette is a mobile genetic element type that contains a recombinant site and a gene. These transgene cassettes express the antigen that is targeted. This takes place under the control of a strong promoter which maintains a vigorous and sustained expression of the transgene.
What are the Similarities Between mRNA and Adenovirus Vaccine?
- Both mRNA vaccine and adenovirus vaccine work with a genetic material that encodes a gene of a pathogen into the cells and gets them to make the particular proteins of the pathogen.
- These vaccines are given for respiratory diseases.
What is the Difference Between mRNA and Adenovirus Vaccine?
The key difference between mRNA and adenovirus vaccine is that mRNA vaccines usually consist of a copy of mRNA with a protective chemical shell, while adenovirus vaccine consists of a harmless virus that encodes the virus spike protein. mRNA vaccine is a vaccine against infectious diseases such as influenza virus, Zika virus, rabies virus, Covid 19 and as well as cancer. Adenovirus vaccine is a vaccine mainly against respiratory diseases. It also acts against HIV, Ebola virus, Influenza virus, Covid 19, Mycobacterium tuberculosis and Plasmodium falciparum. Moreover, mRNA vaccine is directly injected into a muscle, whereas adenovirus is given orally. In addition, mRNA vaccines are easier to create than antigen proteins or attenuated virus. The speed of design and production of mRNA vaccines are higher than adenovirus vaccines.
The below infographic represents the difference between mRNA and adenovirus vaccine.
Summary – mRNA vs Adenovirus Vaccine
mRNA vaccine is a type of vaccine that uses a copy of mRNA to produce an adaptive immune response. mRNA is complementary to one of the DNA strands of a gene. Here, mRNA vaccine introduces mRNA encoding disease-specific antigens and stimulates the protein synthesis of the host cells to produce antigens. This produces an immune response. Adenovirus vaccines are orally administered capsules that contain live viruses. It mainly acts against adenovirus infections. Adenovirus is a double-stranded DNA virus, and it is species-specific, thus consisting of various serotypes for a variety of species. The capsule of adenovirus is usually coated so that the virus passes through the stomach, causing an infection in the intestines. This stimulates an immune response. Thus, this is the summary of the difference between mRNA and adenovirus vaccine
Reference:
1. Dutta, D. (2021, March 10). What are Adenovirus-based Vaccines? Retrieved May 16, 2021, from here.
2. Pardi, N., Hogan, M. J., Porter, F. W., & Weissman, D. (2018). Mrna vaccines — a new era in vaccinology. Nature Reviews Drug Discovery, 17(4), 261-279. doi:10.1038/nrd.2017.243
Image Courtesy:
1. “Solo-mrna-vaccine-12” By Spencerbdavis – Own work (CC BY 4.0) via Commons Wikimedia
2. “Adenovirus 3D schematic” By Thomas Splettstoesser (www.scistyle.com) – Own work (CC BY-SA 4.0) via Commons Wikimedia