mRNAs were touted as safer options compared with DNA vaccines. Reason- mRNAs will not influence our genetic material or integrate in our genome, unlike DNA vaccines, which potentially can. New studies suggest that this is not the case. The notion that viral mRNAs are innocuous and will not modulate our genetic material is being proved wrong on several fronts.
COVID-19 pandemic catapulted the field of mRNA technology to the forefront. RNA-based therapeutics such as the antisense oligos, RNA interference (RNAi), micro-RNA (miRNA) and messenger RNA (mRNA) have all been tested in clinical trials with little success in the past. mRNA-based vaccines have been tried in clinical trials for viruses such as Zika, HIV-1, Rabies, and Influenza. Moderna’s Zika (NCT03014089) and influenza (NCT03076385) mRNA vaccine trials did not progress beyond Phase II and Phase I, respectively.
Viruses do what they normally do- integrate in our DNA to evade our immune system
We have known for a long time that a number of viruses after successfully being taken up by the host cells, evade the immune system and go dormant. To do so, they become integrated into the hosts’ genome/DNA. For example, despite being exposed to HIV virus in sufficient quantity, the individual rarely develops AIDS right away. The HIV virus evades the immune system and becomes part of that individual’s genome by integrating in their cell’s DNA (the cells’ identity is still unknown to us). The HIV virus carries a specific enzyme called reverse transcriptase and upon entry into the hosts cells, makes DNA copies of its RNA genome and then uses the “integrase” function to insert its reverse transcribed DNA genome in non-dividing cells. The exact position of where the virus inserts itself in the host genome cannot be predicted and is random. Although, there are some “hotspots” for the viruses to integrate, but integration is still a random event. In a similar fashion, several other viruses, whether with RNA or DNA as their genome, once they enter the host cell and can successfully evade or fool the hosts’ immune system to perform some initial replication (or make copies of itself for which they use host’s resources) and then go dormant by inserting themselves in the hosts’ genome. The…