How COVID has led to breakthroughs in virus understanding

The past 2 years of the pandemic have led to an explosion of research focused on COVID-19.^[] Researchers have published more than 230,000 journal articles, ranging from studies on vaccine efficacy and antiviral drugs to more basic research topics such as viral structure and immune evasion strategies.

The billions of dollars that have been invested in COVID-19 research have the potential to yield medical breakthroughs for years to come that may help researchers tackle other diseases using the novel technologies developed during this pandemic.

Success of mRNA vaccines

One of the biggest breakthroughs to come out of the COVID-19 pandemic has been the success of the COVID-19 mRNA vaccines, which has highlighted the power and utility of mRNA-based therapeutics.^[]

This mRNA (also known as messenger RNA) is made during transcription from DNA (our genetic material) and will eventually become a protein. The mRNA molecule is responsible for carrying DNA's message from the nucleus to ribosomes in the cytoplasm, where proteins are assembled.

mRNA vaccines use mRNA that is created in a laboratory to teach our cells how to make a protein that triggers an immune response in our bodies. This immune response, which produces antibodies, is what helps protect us from getting sick from that germ in the future. It’s important to note that the mRNA from the COVID-19 vaccines does not enter the nucleus of the cell where our DNA is located, so it cannot change or influence our genes.

The developmental pipeline now includes multiple mRNA vaccines targeting other pathogens (germs aka antigens). In addition, mRNA-encoding antibodies are being developed as a passive immunization tool against various infectious agents.

Researchers are aiming to create mRNA-based vaccines for pathogens such as Zika, HIV, and respiratory syncytial virus (RSV), which is responsible for the hospitalization of 3 million children below the age of 5 each year.

Autoantibodies against interferon

An important pandemic breakthrough that changed the way scientists think about the immune response to viral invaders was the discovery that 15 to 20% of elderly patients over the age of 70 who succumbed to COVID had autoantibodies that attack interferons.

Interferons are a key component of the immune system that act as the first line of defense against viral pathogens (germs aka antigens).

In a healthy immune response, we create antibodies that attach to antigens and tag this complex for destruction, fighting off an infection. Autoantibodies occur when the body’s immune system cannot differentiate between a pathogen (antigen) or the body’s own proteins, and as a result these antibodies attack both the good and bad cells, attacking the interferons (the good cells) and preventing the body from fighting off an infection.

The autoantibodies that target interferon allow the virus to multiply unchecked, leading to a massive infection that eventually causes the immune system to become hyperactivated. The end result is a potentially fatal cytokine storm.

Researchers believe that these autoantibodies may explain why certain patients are unable to fight off certain viral diseases, such as influenza.

This discovery “goes far beyond the impact of COVID-19,” said Gary Michelson, MD, founder and co-chair of Michelson Philanthropies, a non-profit organization that provides funding for medical research, in a 2022 article published by Kaiser Health News. “These findings may have implications in treating patients with other infectious diseases."

Researchers have found that one-third of patients with adverse reactions to yellow fever also have autoantibodies against interferon.

Challenging pre-existing assumptions

Prior to the pandemic, public health policies were created based on the assumption that viruses spread in one of two ways.

The prevailing perception was that viruses could spread through the air; think air conditioners, air filters and vents (as with measles or tuberculosis), or through droplets in the air when people cough, sneeze, or talk (as with influenza).

For the first year- and-a-half of the pandemic, the Centers for Disease Control and the World Health Organization said that COVID-19 spreads through droplets, and advised individuals to keep a distance of 6 feet from other people, wear face coverings, and wash their hands. However, as the pandemic continued, scientists began to question whether COVID-19 was also airborne.

This information is critical, because it has the potential to change public health policies. For instance, N95 respirators can be utilized to protect against airborne viruses instead of cloth or surgical masks.

Similarly, airborne viruses can be better controlled by improving ventilation, so that the air in a room is completely replaced at least four times an hour.