HomeNewsBusinessCompaniesExplained: What are VLP-based Covid-19 vaccines, and why is the platform attracting vaccine cos?

Explained: What are VLP-based Covid-19 vaccines, and why is the platform attracting vaccine cos?

Two VLP vaccines have reached the clinical trial stage. Canadian biotech firm Medicago, backed by tobacco behemoth Phillip Morris, vaccine candidate based on VLP has reached phase 2/3 trial.

December 30, 2020 / 07:40 IST
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Serum Institute of India (SII) has announced it has partnered with UK biotech company, Spybiotech, a spin-off of the University of Oxford, to develop a COVID-19 virus-like-particle (VLP)-based vaccine. The vaccine has entered a Phase 1/2 trial in Australia. In October, another Indian drug maker, Aurobindo Pharma, said it entered into collaboration with Hyderabad-based Centre for Cellular and Molecular Biology (CCMB), a Council of Scientific and Industrial Research (CSIR) lab, to manufacture a COVID-19 vaccine based on VLP.

It isn't SII and Aurobindo Pharma alone, there more than a dozen COVID-19 vaccine candidates currently under development that are based on VLP.

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What is VLP?

VLP resembles the SARS-CoV-2 virus. The VLP is constructed incorporating all key structural proteins, mirroring the molecular structure of coronavirus. However, it doesn't cause infection as it doesn't have the genetic material that helps it replicate like a natural virus. VLPs can be produced using mammalian cells, insect cells, bacteria, yeast and plant cells. Animal studies have found out that vaccines based on VLP induce immune response, providing protection against any future COVID-19 infection. To be sure, there are several VLP-based vaccines commercially available including vaccines against Human Papilloma Virus (HPV) and Hepatitis B Virus (HBV). Most licensed VLP vaccines use the aluminum adjuvant to boost their efficacy.

COVID-19 Vaccine
Frequently Asked Questions

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How does a vaccine work?

A vaccine works by mimicking a natural infection. A vaccine not only induces immune response to protect people from any future COVID-19 infection, but also helps quickly build herd immunity to put an end to the pandemic. Herd immunity occurs when a sufficient percentage of a population becomes immune to a disease, making the spread of disease from person to person unlikely. The good news is that SARS-CoV-2 virus has been fairly stable, which increases the viability of a vaccine.

How many types of vaccines are there?

There are broadly four types of vaccine — one, a vaccine based on the whole virus (this could be either inactivated, or an attenuated [weakened] virus vaccine); two, a non-replicating viral vector vaccine that uses a benign virus as vector that carries the antigen of SARS-CoV; three, nucleic-acid vaccines that have genetic material like DNA and RNA of antigens like spike protein given to a person, helping human cells decode genetic material and produce the vaccine; and four, protein subunit vaccine wherein the recombinant proteins of SARS-COV-2 along with an adjuvant (booster) is given as a vaccine.

What does it take to develop a vaccine of this kind?

Vaccine development is a long, complex process. Unlike drugs that are given to people with a diseased, vaccines are given to healthy people and also vulnerable sections such as children, pregnant women and the elderly. So rigorous tests are compulsory. History says that the fastest time it took to develop a vaccine is five years, but it usually takes double or sometimes triple that time.
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