Viruses can do good

As we reel under a viral pandemic that has already killed almost 6 million people, it is hard to imagine how viruses could benefit humanity. These microscopic pathogens have a bad reputation for causing infectious, near-fatal diseases like rabies, measles, smallpox, HIV-AIDS, and Covid-19. But, humans have turned some of the 9,000 known virus species into our helpers using gene editing.

A virus infects our cells by hijacking their DNA. Instead of creating copies of the cell, the virus ends up replicating itself. Now, scientists are using this mechanism to our advantage. They are genetically modifying adenoviruses, retroviruses and adeno-associated viruses to treat damaged genes in our cells. Genetically-modified viruses with the ‘corrected’ gene are made to sneak into cells with damaged genes and restore them. In 2012, the first viral gene therapy was approved to treat lipase (an enzyme that breaks down fats) deficiency.

Genetically-modified viruses have also been used to develop vaccines like the Oxford/AstraZeneca Covid-19 vaccine. Harmless viruses, like the adenovirus, are used as ‘vectors’ that are genetically altered to contain specific proteins of a harmful virus like the SARS-CoV-2. When such viruses enter our bloodstream, our body’s immune system produces antibodies, thus prepping our immunity to tackle a potent infection.

Viruses are also doubling as anticancer agents. When cancer is treated with chemotherapy, radiation therapy or surgery, healthy, non-cancerous cells are also damaged. Scientists are now experimenting with specific oncolytic viruses, which infect and kill only cancerous cells and spare healthy ones. In 2015, the US Food and Drug Administration approved the first oncolytic viral therapy using herpes virus to treat skin cancer. Clinical trials to similarly treat cancer in the blood, brain, lung, breasts, prostrate, ovaries and pancreas are underway.

Viruses, as it turns out, can also do good.

Spoorthy Raman