COVID-19 has swept through the world so quickly that it’s been hard to keep up with the latest news. This uncertainty can lead to a fair amount of anxiety, especially when you’re isolated at home. We thought we’d bust some of the myths out there – so you’ll be up to speed on what is currently known about the virus.
FICTION – There are a lot of differences between COVID-19, which is caused by the SARS-CoV-2 virus and the flu, which is caused by the influenza virus. SARS-CoV-2 infects host cells when the spike protein on the virus surface interacts with the ACE2 receptor on the host cell. Influenza A, for example, infects host cells when the viral hemagglutinin protein interacts with sialyl receptors on the host cell1. The influenza virus also mutates much faster than SARS-CoV-2, which is why you need a flu shot every year2.
More importantly, the mortality rate for COVID-19 appears to be higher right now compared to influenza. Data collected so far indicates that the mortality rate for COVID-19 is somewhere between 1- 4%, an estimate that may be impacted by the availability of testing, while the mortality rate for seasonal influenza is usually below 0.1%. However, the mortality rate for COVID-19 should decrease as therapeutics and vaccines become available.
Maybe –-COVID-19 is primarily transmitted through liquid droplets emitted when someone coughs according to the World Health Organization (WHO)3 and other health agencies. However, a recent study published in the New England Journal of Medicine suggests that the SARS-CoV-2 virus can be aerosolized4. Further studies need to be completed to determine whether the virus can be aerosolized with just normal breathing. If it can, the argument for wearing masks, even if you aren’t sick, becomes that much more compelling.
FACT – According to the WHO, it’s unlikely that packages like grocery deliveries will carry the virus since it has been moved, traveled, and exposed to different temperatures and conditions. In fact, recent studies indicate the SAR-CoV-2 virus only survives on cardboard for about a day and plastic and stainless steel for two to three days4.
FICTION – Initially, data from China seemed to indicate that only older patients or those with underlying conditions like heart disease suffered from more severe symptoms. However, recent data from the CDC shows that younger adults don’t always respond to COVID-19 with mild symptoms5. As of March 16, 2020, 38% of hospitalized patients were between 20-54 years old and half of the patients who required intensive care were younger than 65. Until we learn more about the disease, it’ll be hard to predict who will have a mild reaction and who will have a severe reaction.
Not necessarily – Inflammation and fever normally occur when the immune system fights off the virus. However, in some cases the immune system continues to release inflammatory cytokines even after the infection has been defeated, leading to what is called a cytokine storm. When this happens, your immune system can become a liability since the cytokines, in the absence of a virus, will attack organs like the lung and liver6.
It’s not clear yet how many people infected with COVID-19 also suffer from cytokine storm. However, the good news is that there are treatment options available to calm down the immune system. Hospitals have reported cases where doctors suspecting a cytokine storm in COVID-19 patients have seen positive outcomes when tocilizumab, a drug that blocks the inflammatory cytokine IL-6, was administered7.
1. Sriwilaijaroen J, et al. N-glycan structures of human alveoli provide insight into influenza virus infection and pathogenesis. FEBS J, 2018; 285(9):1611-1634.
2. Relatively Stable SARS-CoV-2 Genome is Good News for a Vaccine. The Scientist, 2020.
3. Modes of transmission of virus causing COVID-19: implications for IPC precaution recommendations. 2020.
4. van Doremalen N, et al. Aerosol and surface stability of HCoV-19 (SARS-CoV-2) compared to SARS-CoV-1. The New England Journal of Medicine, 2020, DOI: 10.1056/NEJMc2004973 (2020).
5. Severe Outcomes Among Patients with Coronavirus Disease 2019 (COVID-19). 2020.
6. Tisoncki JR, et al. Into the Eye of the Cytokine Storm. Microbiol Mol Bio Rev. 2012, 76(1):16-32.
7. The Coronavirus Patients Betrayed by Their Own Immune System. 2020.