A new study carried out by the researchers from the University of Arizona in the United States has found that the coronavirus can relieve pain.

The scientists believe that this could be the reason why almost half the people demonstrate few or no symptoms of the virus. They aim to prove that the relief of pain is the reason behind the unrelenting spread of the virus.

Scientists, through their study published in the journal PAIN , intended to prove that early symptom of Covid-19, may be reduced by the coronavirus spike protein as it silences the body’s pain signaling pathways.

During the early stage of the pandemic, some researchers had established that the virus targets only ACE2 receptor cells. However, later they discovered SARS-CoV-2 also targets neuropilin-1 as a second receptor.

After this study, researchers started speculating that the spike protein is involved in some sort of pain processing.

The researchers wrote in their study that many biological pathways signal the body to feel pain. One is through a protein named vascular endothelial growth factor-A (VEGF-A), which plays a vital role in the growth of blood vessels. However, it is also linked to diseases such as cancer, rheumatoid arthritis, and, most recently, Covid-19.

Like a key in a lock, when VEGF-A binds to the receptor neuropilin, it initiates a cascade of events resulting in the hyperexcitability of neurons, which leads to pain.

The team found that the SARS-CoV-2 spike protein binds to neuropilin in exactly the same location as VEGF-A. They performed a series of experiments in the laboratory and in rodent models to test their hypothesis that the SARS-CoV-2 spike protein acts on the VEGF-A/neuropilin pain pathway. They used VEGF-A as a trigger to induce neuron excitability, which creates pain, then added the SARS-CoV-2 spike protein.

Researchers concluded that the spike completely reversed the VEGF-induced pain signaling. It reversed the pain completely.