COVID-19 Vaccine Knowledge: What is a VLP vaccine?
COVID-19 Vaccine Knowledge: What is a VLP vaccine? VLP stands forvirus-like particle. Virus-like particles are molecules that mimic viruses but are not infectious. They are very effective methods for producing vaccines against human papillomavirus (HPV), hepatitis B, malaria and other diseases.
How does the VLP vaccine work?
The virus-like particle is non-infectious because it does not contain any viral genetic material. Since they are very similar to real virus molecules, the introduction of VLP into the body triggers an immune response, but a person will not suffer any symptoms of the virus to be vaccinated.
VLP is composed of one or more structural proteins that can be arranged in multiple layers. They can also contain an outer lipid envelope, which is the outermost layer covering a large number of different viruses. This outer layer protects the genetic material inside the virus particle. In some viruses, the envelope may contain material that infects the virus, which helps the immune system not detect them.
VLP vaccines can be created using bacteria, yeast, insects or mammalian cells. The cell type selected depends on the cost of producing the vaccine in this way and whether the VLP needs to be modified in the future to trigger the strongest immune response through post-translational modification (PTM).
A study concluded that among 174 VLP vaccines, 28% of cases used bacterial systems to make VLPs, 20% of bacteria used yeast systems, and 28% of insects used bacterial systems. Plant and mammalian systems were used in 9% and 15% of cases, respectively.
Types of VLP vaccines
There are many different types of vaccines, including:
1. Live attenuated vaccine
2. Inactivated vaccine
3. Subunit, recombinant, polysaccharide or conjugate vaccine
4. Toxoid vaccine.
VLP vaccines are a kind of recombinant vaccines, but they have the efficacy of attenuated live vaccines. Recombinant vaccines use specific bacteria that the immune system specifically targets.
Usually, the immune response to this vaccine is very strong, but sometimes it is necessary to boost the vaccine to maintain immunity. One of the main advantages of recombinant vaccines is that it is suitable for people with weakened immune systems .
There are about 110 kinds of VLPs made from viruses from 35 different families, and the scientific award has greatly increased the research interest in this field.
The human papillomavirus vaccine (also known as cervical cancer vaccine) is a commonly used VLP vaccine. It is the first vaccine provided for boys and girls between 12 and 13 years old. In HPV vaccines, VLPs are formed by the main capsid protein L1, which is a protein found on the outer shell of bacteria.
Virus-like particles are also very small, with a particle radius of approximately 20 to 200 nm. This means that they can easily enter the lymph nodes. In the case of infection, the immune system will be activated, and it has been proven that VLP can reach the lymph nodes in less than 10 minutes.
More and more research discusses the development of vaccines based on nanoparticles (including VLP). The advantages of these nanoparticle-based vaccines are that they are considered to be highly specific, very effective, and have good pharmacokinetic properties.
Nanoparticle-based VLP vaccines can also eliminate the need for vaccine injections and may be used in intranasal vaccines or inhalers.
What are the benefits of VLP vaccine?
VLP VLP vaccines thanks to the ability to present the antigen in a repetitive manner, this capability allows fine B cell receptor (B cell receptor, BCR) crosslinking.
VLP has a repetitive surface pattern and a particulate structure that can trigger a strong immune response, which can help people enhance their immunity to diseases. They have also been shown to be very safe for people who are vaccinated and those who produce and administer vaccines.
This is because there is no live viral material in the virus-like particles, which means that the person who produces the vaccine will not contract the virus on their own. This also means that anyone who is vaccinated will not be infected with the virus if exposed to the particles.
Because the virus is easy to mutate, making previous vaccines ineffective in some cases, VLP is a promising option to solve this problem. This is because the surface proteins of VLPs can be modeled to compete with specific combinations of proteins on new viruses.
VLP cannot replicate either, which makes it safer than attenuated vaccines.
What are the risks of VLP vaccine?
The risks of VLP vaccines are basically the same as other types of vaccines. Any side effects experienced may depend on the disease targeted by the vaccinee.