Different technologies have been utilized to develop vaccines such as DNA/RNA- based, virus vectors, inactivated vaccines, live-attenuated virus and protein subunit. The World Health Organization has listed around 180 vaccines and all take a different approach in fighting COVID-19. However, they can categorized into the five groups listed above. Read on to learn the pros and cons of each vaccine approach!
DNA/RNA-based
DNA and RNA vaccines are made from fragments of manmade genetic material, which mimic a part of the virus. When the vaccine is injected into your body, your body follows the instructions in the DNA or RNA, and produces copies of the vaccine part and your immune system strikes back. This procedure allows your body to practice protecting you from foreign substances, so it can protect you when there is a real threat.
Pros:
- can be quickly designed
- easily manufactured
- potentially cheap to produce
- DNA/RNA do not cause COVID-19
Cons:
- currently no approved DNA/RNA vaccines for medical use in humans, so there may approval issues
- because only a fragment of the virus is produced and injected, it may result in a poor and unreliable protective immune response
- vaccine DNA may integrate into your genome
Virus Vectors
These vaccines use a weakened virus incapable of causing disease itself to deliver virus antigens into your body. Virus antigens are molecular structures found on the surface of a virus, which can be recognized by your immune system and can trigger an immune response. As the virus infects cells and uncovers large amounts of antigen, your body will demonstrate a strong immune response and be able to protect your body if you do come into contact with COVID-19.
Pros:
- can deliver antigen to target specific cells
- a single dose can promote long-term protection
Cons:
- low production of virus-vectored vaccines means expensive to produce
Inactivated Vaccines
Inactivated vaccines consist of viruses altered through heat, chemicals, or radiation so they can't multiply in your body and harm you. However, they can still promote an immune response and in turn, protect you in the long run.
Pros:
- well-known, studied technology
- used in a variety of different vaccines so considered safe
- can still be used with weakened immune systems
Cons:
- has difficulty triggering strong immune responses, so you may need a larger dose
Live-attenuated Virus
Similar to inactivated vaccines, live-attenuated vaccines are weakened and cannot cause disease. However, once inserted into your body, they can grow and multiply to trigger a strong immune response.
Pros
- vaccine imitates the natural infection process, promoting strong protection
- easily manufactured
- cheap to produce
- strong immune response means single vaccination
Cons
- rare, but possible chance of being able to cause diseases again
- limited use in those with weakened immune systems
-can require cold storage, limiting distribution
Protein Subunit
Protein subunit vaccines lack live components of the virus, but consist of purified parts of the virus (protein antigens) that promote an immune response.
Pros
- containing no live components, so generally safe
- can still be used with weakened immune systems
Cons
- has difficulty triggering strong immune responses, so you may require a larger dose
Written by: Ashlee Liu
References:
“The Pros and Cons of Different COVID Vaccine Technologies Explained.” The National Interest, 20 Sept. 2020, nationalinterest.org/blog/reboot/pros-and-cons-different-covid-vaccine-technologies-explained-169291.
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