What is the COVID-19 virus called?
The official names for the virus responsible for COVID-19 (previously known as “2019 novel coronavirus”) and the disease it causes are:
- Disease: CoronaVIrus Disease of 2019 (acronym: COVID-19). This name was given by the World Health Organization (WHO) on February 11, 2020.
- Virus: Severe Acute Respiratory Syndrome CoronaVirus 2 (SARS-CoV-2).
Viruses are named based on their genetic structure to facilitate the development of diagnostic tests, vaccines and medicines. Diseases are named to enable discussion on disease prevention, spread, transmissibility, severity and treatment.
How does COVID-19 compare with other respiratory diseases?
The flu is a disease caused by a family of viruses called influenza viruses. Like coronaviruses, they carry their genetic information in the form of RNA. Coronaviruses and influenza viruses cause respiratory diseases. However, they function differently. For example, the genome of the influenza A viruses comprise 8 single-stranded RNA molecules, while the typical generic coronavirus genome is a single strand of RNA, 32 kilobases long, and is the largest known RNA virus genome (1).
Only 7 coronaviruses are known to cause disease in humans. 4 of them cause symptoms of the “common cold”, while 3 human coronaviruses cause much more serious lung infections, also called pneumonia. Those 3 coronaviruses are named SARS-CoV which causes SARS (severe acute respiratory syndrome), MERS-CoV which causes Middle East Respiratory Syndrome or MERS), and SARS-CoV2, responsible for the COVID-19 (disease).
Because those 3 coronaviruses present the most similarities, COVID-19 research efforts are building on earlier research done on SARS-CoV and MERS-CoV. Current research evidence suggests that SARS-CoV and MERS-CoV originated in bats, and it is likely that SARS-CoV-2 did as well. SARS-CoV then spreads from infected civets to people, while MERS-CoV spreads from infected dromedary camels to people. As of April 2020, scientists are still trying to determine how SARS-CoV-2 spread from an animal reservoir to people (2)
The COVID-19 virus is the most infectious of the coronaviruses
SARS and MERS have significantly higher case fatality rates than COVID-19. Yet COVID-19 is more infectious, meaning that the SARS-CoV-2 virus spreads more easily among people, leading to greater case numbers. As a result, despite the lower fatality rate, the overall number of deaths from COVID-19 far outweighs that from SARS or MERS.
How does the COVID-19 virus replicate?
The coronavirus SARS-CoV-2 is an RNA virus, meaning that it carries and “injects” its genetic material (viral RNA) into a cell in order to reproduce. Viral RNA contains the blueprints for all of the components of a particular virus. The viral genetic material is then replicated by the host cell. RNA viruses typically infect mammals, including humans and bats. RNA is a molecule similar to DNA, and it is essentially a temporary copy of a short segment of DNA.
A summary of the COVID-19 safety guidelines
Wash your hands often with soap and water for at least 20 seconds especially after you have been in a public place, or after blowing your nose, coughing, or sneezing. Avoid touching your eyes, nose, and mouth with unwashed hands.
Avoid close contact with people who are sick, even inside your home. Put distance between yourself and other people outside of your home. Remember that some people without symptoms may be able to spread virus.
Stay out of crowded places and avoid mass gatherings.
Cover your mouth and nose with a cloth face cover when around others. You could spread COVID-19 to others even if you do not feel sick. Do not use a facemask meant for a healthcare worker.
Cover coughs and sneezes with a tissue when you cough or sneeze or use the inside of your elbow. Throw used tissues in the trash. Immediately wash your hands or clean your hands with a hand sanitizer that contains at least 60% alcohol.
Clean and disinfect frequently touched surfaces daily. This includes tables, doorknobs, light switches, countertops, handles, desks, phones, keyboards, toilets, faucets, and sinks. If surfaces are dirty, clean them. Use detergent or soap and water prior to disinfection. Then, use a household disinfectant.
Vaccine candidates that are being tested
The genetic sequence of SARS-CoV-2, the coronavirus that causes COVID-19, was published on 11 January 2020, triggering intense global R&D activity to develop a vaccine against the disease. A vaccine to prevent coronavirus disease 2019 (COVID-19) is perhaps the best hope for ending the pandemic. Currently, no approved vaccines exist to prevent infection with SARS-CoV-2, but researchers are racing to create one. The first COVID-19 vaccine candidate entered human clinical testing with unprecedented rapidity on 16 March 2020. The most advanced candidates have recently moved into clinical development, including mRNA-1273 from Moderna, Ad5-nCoV from CanSino Biologicals, INO-4800 from Inovio, and LV-SMENP-DC and pathogen-specific aAPC from Shenzhen Geno-Immune Medical Institute.
Numerous other vaccine developers have indicated plans to initiate human testing in 2020. A striking feature of the vaccine development landscape for COVID-19 is the range of technology platforms being evaluated, including nucleic acid (DNA and RNA), virus-like particle, peptide, viral vector (replicating and non-replicating), recombinant protein, live attenuated virus and inactivated virus approaches.
Past research on vaccines for coronaviruses has identified some challenges to developing a COVID-19 vaccine, including:
- Ensuring vaccine safety. A COVID-19 vaccine will need to be thoroughly tested to make sure it's safe for humans.
- Providing long-term protection. An effective COVID-19 vaccine will need to provide people with long-term infection protection.
- Protecting older people. People older than age 50 are at higher risk of severe COVID-19. But older people usually don't respond to vaccines as well as younger people. An ideal COVID-19 vaccine would work well for this age group.
mRNA-1273A: Phase 1 clinical trial evaluating an investigational vaccine designed to protect against coronavirus disease 2019 (COVID-19) has begun at Kaiser Permanente Washington Health Research Institute (KPWHRI) in Seattle (1)
Inovio's proprietary platform hand-held smart device called CELLECTRA® delivers optimized DNA into cells, where it is translated into proteins that activate an individual's immune system. The device uses a brief electrical pulse to open small pores in the cell reversibly to allow the plasmids to enter. Once inside the cell, the plasmids begin replicating, thereby strengthening the body's own natural response mechanisms. On April 28, 2020 - INOVIO announced that its Phase 1 clinical trial for COVID-19 DNA vaccine INO-4800 is fully enrolled and safety results expected in late June 2020.
The Ad5-nCoV Vaccine uses adenovirus to deliver the DNA for a coronavirus protein. The vaccine is a hybrid of “live virus” and “recombinant protein” being used to generate protein antigens to trigger the antibodies production against Coronavirus in the patient's body. Ad5-nCoV is a genetically engineered vaccine candidate with the replication-defective adenovirus type 5 as the vector to express SARS-CoV-2 spike protein, which intends to be used to prevent COVID-19.
LV-SMENP-DC is a recombinant adenovirus type-5 vector (Ad5) vaccine. a synthetic minigene has been engineered based on conserved domains of the viral structural proteins and a polyprotein protease to express viral proteins and immune modulatory genes to modify immune cells. in March 2020 a phase I clinical trial was approved with an expected completion in December 2020. The Phase 1 trial is now complete and the company is enrolling patients for a Phase 2 trial. This vaccine has been named as a top contender by the World Health Organization (2, 3).
The PiCoVacc vaccine is an old-fashioned formulation consisting of a chemically inactivated version of SARS-CoV-2. It induced SARS-CoV-2-specific neutralizing antibodies in mice, rats and non-human primates. These antibodies neutralized 10 representative SARS-CoV-2 strains. Phase 1 trial began on 16 April (4).
The Shenzhen Geno-Immune Medical Institute’s aAPC vaccine is an artificial antigen-presenting cells (aAPC) vaccine prepared by transfection of aAPCs with a genetically-modified lentivirus encoding the SARS-CoV-2 structural and protease protein domains to aAPCs, which are delivered by three subcutaneous injections.
Additional scientific resources
- 2019 Novel Coronavirus (COVID-19) Outbreak: A Review of the Current Literature and Built Environment (BE) Considerations to Reduce Transmission
- Aerosol and surface stability of HCoV-19 (SARS-CoV-2) compared to SARS-CoV-1
- Transmission Potential of SARS-CoV-2 in Viral Shedding Observed at the University of Nebraska Medical Center
- Air, Surface Environmental, and Personal Protective Equipment Contamination by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) From a Symptomatic Patient
- Surface sampling of coronavirus disease (COVID-19): A practical “how to” protocol for health care and public health professionals
- Environmental Contamination and Viral Shedding in MERS Patients During MERS-CoV Outbreak in South Korea
- Extensive Viable Middle East Respiratory Syndrome (MERS) Coronavirus Contamination in Air and Surrounding Environment in MERS Isolation Wards