Remember the era of Covid-19 pandemic? Remember how the whole world was shut down because of a tiny little virus. That is how scary and dangerous a tiny virus can be. Unlike bacterial infections, which can often be treated with antibiotics, treatment for viral infection is much more complicated. Vaccines are usually an effective way to cope with viral infection. However, vaccines are not always readily available for certain diseases. Furthermore, certain viruses possess the ability to continuously evolve and rapidly change their genetic makeups leading to a variety of variants, making it very difficult for a single vaccine to prevent infection.

This underscores the innovative approach of antiviral drugs to directly stop or kill the viruses upon infection.

Knowing the nature of virus replication, the main strategies used by researchers in the development of antiviral drugs are:

1. direct-targeting on the virus or viral protein, or
2. targeting the cellular (host) processes that are crucial for viral attachment, replication and growth.

Newly developed antiviral drugs must undergo various rigorous testing stages to ensure their safety and effectiveness before being released into the market. Currently, there are a few successfully developed antiviral drugs available in the market against influenza viruses, herpes virus and HIV.

Here at TECOLAB, we are on a mission to contribute to the field of drug development. Through in vitro testing methods, we have developed an approach for preliminary antiviral drug assessment. An ideal drug should exhibit minimal harm to cells while demonstrating potent antiviral effectiveness. The candidate drug needs to be screened for its cytotoxicity. Most drugs fail to make it to the market due to its toxicity that causes harm to normal healthy cells. These toxicity tests are performed in accordance with the ISO 10993-5.

A key step to antiviral drug development is to evaluate the safety and antiviral activity of the drug. The test drug may be introduced or added at different stages of viral infection, namely:

1. pre-infection (before addition of virus)
2. post-infection (after the addition of virus)
3. pre-incubated together with the virus (co-treatment) before being added to the host cells

This step is to determine the stage at which the drug inactivates or prevents the viral infection. We have developed our initial drug screening tests by mainly employing phenotypic assays such as cytopathic effect (CPE) inhibition and TCID50 assay.