A new study suggests that COVID-19 relieves pain, which is why many patients do not experience any symptoms.
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes coronavirus disease 2019 (COVID-19), can relieve pain, according to a recent study published in Pain.
The COVID-19 pandemic has caused more than 1 million deaths and there has been over 35.3 million confirmed cases worldwide, according to the World Health Organization. Nearly half of people who contract the virus have few or no symptoms, even though they are able to spread the virus, according to the study. CDC data estimate that 50% of COVID-19 transmission occurs prior to the onset of symptoms and 40% of COVID-19 infections are asymptomatic, according to the study.
Investigators believe this may be due to the receptors on the SARS-CoV-2 virus. According to the study, early on in the pandemic, it was discovered that SARS-CoV-2 spike protein uses the angiotensin-converting enzyme 2 (ACE2) to enter the body. In June, a second receptor called neuropilin-1 was discovered.
Investigators found that a protein called vascular endothelial growth factor-A (VEGF-A), which plays an essential role in blood vessels and has been linked to diseases such as cancer, also plays an essential role in COVID-19. VEGF-A binds the receptor to neuropilin, which causes pain.
However, in the case of COVID-19, the spike proteins bind VEGF-A in the same place. Investigators believe that this reverses the VEGF-induced pain signaling.
"Spike completely reversed the VEGF-induced pain signaling. It didn't matter if we used very high doses of spike or extremely low doses—it reversed the pain completely,” corresponding author Rajesh Khanna, PhD, said in the press release.
Investigators said they are currently designing small molecules against neuropilin. Not only do the study’s findings help with the COVID-19 pandemic, but they can potentially help the opioid pandemic as well.
"We have a pandemic, and we have an opioid epidemic. They're colliding. Our findings have massive implications for both. SARS-CoV-2 is teaching us about viral spread, but COVID-19 has us also looking at neuropilin as a new non-opioid method to fight the opioid epidemic," Khanna said.
Pain relief caused by SARS-CoV-2 infection may help explain COVID-19 spread [News Release] Tucson, AZ; October 1, 2020. https://www.sciencedaily.com/releases/2020/10/201001155912.htm. Accessed October 6, 2020.