Coronavirus explained: Symptoms, lockdowns and all your COVID-19 questions answered
The most-asked questions about the pandemic include ones about stimulus checks, face masks and the virus' origins.
Jackson RyanFormer Science Editor
Jackson Ryan was CNET's science editor, and a multiple award-winning one at that. Earlier, he'd been a scientist, but he realized he wasn't very happy sitting at a lab bench all day. Science writing, he realized, was the best job in the world -- it let him tell stories about space, the planet, climate change and the people working at the frontiers of human knowledge. He also owns a lot of ugly Christmas sweaters.
Researchers linked the pathogen to a family of viruses known as coronaviruses in January. That family contains viruses responsible for previous outbreaks of the respiratory diseases SARS and MERS, as well as some cases of the common cold. On March 11, Tedros Adhanom Ghebreyesus, director-general of the World Health Organization, announced the outbreak of the disease, dubbed COVID-19, would be declared a pandemic. It is the first time any coronavirus has been characterized as such.
The situation continues to evolve as more information becomes available. We've collated everything we know about the virus, what's next for researchers, what steps you can take to reduce your risk, how to deal with quarantines and lockdowns, and how governments are providing assistance such as stimulus checks.
Coronaviruses contain a single strand of RNA (as opposed to DNA, which is double-stranded) within their viral body (or "viral envelope"). As a virus, they can't reproduce without getting inside living cells and hijacking the machinery within. The spikes on the viral envelope help coronaviruses bind to cells, and then get inside them as if jimmying their way through a locked door. Once inside, they turn the cell into a virus factory -- the RNA and a handful of enzymes use the cell's machinery to produce more viruses, which are then shipped out of the cell and infect other cells. Thus, the cycle starts anew.
Coronavirus in pictures: Scenes from around the world
Typically, these types of viruses are found in animals ranging from livestock and household pets to wildlife such as bats. Some are responsible for disease, like the common cold. If they make the jump to humans, they can cause fever, respiratory illness and inflammation in the lungs. In immunocompromised individuals, such as the elderly or those with HIV-AIDS, such viruses can cause severe respiratory illness, resulting in pneumonia and even death.
Extremely pathogenic coronaviruses were behind the diseases SARS (severe acute respiratory syndrome) and MERS (Middle East respiratory syndrome) over the last two decades. These viruses were easily transmitted from human to human but were suspected to have passed through different animal intermediaries: SARS was traced to civet cats and MERS to dromedary camels. SARS, which showed up in the early 2000s, infected more than 8,000 people and resulted in nearly 800 deaths. MERS, which appeared in the early 2010s, infected almost 2,500 people and led to more than 850 deaths.
The Coronavirus Study Group, part of the International Committee on Taxonomy of Viruses, was responsible for naming the novel coronavirus itself. The novel coronavirus -- the one that causes the disease -- is known as SARS-CoV-2. The group "formally recognizes this virus as a sister to severe acute respiratory syndrome coronaviruses (SARS-CoVs)," the species responsible for the SARS outbreak in 2002-2003.
In the simplest terms:
The novel coronavirus is officially named SARS-CoV-2.
The disease caused by SARS-CoV-2 is officially named COVID-19.
"Pandemic is not a word to use lightly or carelessly. It is a word that, if misused, can cause unreasonable fear, or unjustified acceptance that the fight is over, leading to unnecessary suffering and death," said Tedros at a press briefing.
So what is it?
Both the CDC and the WHO have different definitions, and if you look in a dictionary, you may find something different again. In the simplest terms, a pandemic can be defined as "a worldwide outbreak of a new disease."
The "new" is key here, because many diseases persist in the population and spread each year. For example, influenza (the flu) infects a lot of people every year and can be found across the world. Unlike COVID-19, it's been circulating in the community for centuries and there's some natural immunity to it, plus we know so much about it we can protect ourselves against common strains.
What does this all mean? The COVID-19 virus itself didn't change. It hasn't become more dangerous and hasn't mutated to infect people more quickly. And the risk of being infected doesn't exponentially increase now that the word "pandemic" is being used. But it's a way to describe what's happening and more succinctly understand the urgency of the situation.
The Huanan Seafood Wholesale Market, which sells fish, as well as a panoply of meat from other animals, including bats, snakes and pangolins, was implicated in the original spread in early January. However, the very first patient identified had not been exposed to the market, suggesting the virus may have originated elsewhere and been transported to the market, where it was able to thrive or jump into new hosts -- whether human or animal. Chinese authorities shut down the market on Jan. 1.
Live animal markets have been implicated in the origin and spread of viral diseases in past epidemics. A majority of the people confirmed to have come down with the coronavirus in the early days of the outbreak had been to the Huanan Seafood marketplace in previous weeks. The market appears to be an integral piece of the puzzle, but research into the likely origin and connecting a "patient zero" to the initial spread is ongoing.
A group of Chinese scientists uploaded a paper to preprint website biorXiv, having studied the viral genetic code and compared it to the previous SARS coronavirus and other bat coronaviruses. They discovered the genetic similarities run deep: The virus shares 80% of its genes with the previous SARS virus and 96% of its genes with bat coronaviruses. Importantly, the study also demonstrated the virus can get into and hijack cells the same way SARS did, using a human receptor known as ACE2.
A paper published in the journal Nature Medicine on March 17 assessed the genome of the virus in great detail, coming to similar conclusions to the preprint, categorically stating that it arose due to natural evolution. "Our analyses clearly show that SARS-CoV-2 is not a laboratory construct or a purposefully manipulated virus," wrote the collaboration of researchers from institutions across the US, UK and Australia.
The ant-eating pangolin, a small, scaly mammal, has also been implicated in the spread of SARS-CoV-2. According to The New York Times, it may be one of the most trafficked animals in the world. The virus likely originated in bats but may have been able to hide out in the pangolin, before spreading from that animal to humans. Researchers caution that the full data hasn't yet been published, but coronaviruses similar to SARS-CoV-2 have been found in pangolins before.
All good science builds off previous discoveries -- and there is still more to learn about the basic biology of SARS-CoV-2 before we have a good grasp of exactly which animal vector is responsible for transmission -- but the genetic sequence of the virus is a clue: It tells us the virus must have originated in bats and may have jumped through an intermediary to a human.
COVID-19 also seems to affect older generations much more severely. A great piece at STAT news breaks down the demographics of the disease and which groups seem particularly at risk.
The bottom line: When looking for how deadly COVID-19 might be, a single number like 3.4% doesn't tell the whole story -- it's much more complex than that. The fatality rate will change over time, but the elderly (older than 60) and those with underlying health conditions, like cardiovascular disease and diabetes, are at higher risk.
Understanding the genetic code helps researchers in two ways: It allows them to create tests that can identify the virus from patient samples, and it gives them potential insight into creating treatments or vaccines.
Respiratory droplets -- when a person sneezes or coughs.
Direct contact with infected individuals.
Contact with contaminated surfaces and objects.
A handful of viruses, including MERS, can survive for periods in the air after being sneezed or coughed from an infected individual. Although recent reports suggest the novel coronavirus may be transmitted in this way, the Chinese Center for Disease Control and Prevention have reiterated there is no evidence for this. Writing in The Conversation on Feb. 14, virologists Ian Mackay and Katherine Arden explain "no infectious virus has been recovered from captured air samples."
Further research has shown SARS-CoV-2 may linger in the air for extended periods of time, which is particularly notable for health workers. It's estimated the virus can stay suspended in the air for a period of about 30 minutes. Social distancing measures become ever more important here because only those close to infected individuals are expected to be exposed to large quantities of the virus in the air.
A study in the New England Journal of Medicine on March 17 took a deeper look at how stable the SARS-CoV-2 virus is in the air and on surfaces. There's a chance the virus survives on cardboard for up to 24 hours, while on copper surfaces it seems to only survive for around 4 hours. On plastic and steel, it might survive up to three days.
A chief concern for the public has been whether package shipments could help spread the virus. Different materials can keep the virus alive for longer outside the body, but a range of factors needs to be taken into account when evaluating virus survival. The CDC is still investigating this but has come up with numbers for certain surfaces.
The CDC will continue to investigate but believes the risk of contracting coronavirus from packages is still low. The WHO notes it is "very unlikely" you would see the coronavirus persist after being moved, traveled and exposed to different conditions.
Best tip? Wash your hands after handling any packages if you're concerned (and just wash your hands, a lot, in general).
That led to widespread reports about making your own hand sanitizer -- but experts warn that you risk making a sanitizer that either isn't effective or is way too harsh.
In CNET's guide to DIY hand sanitizer, we also rule out using hard liquor. Recipes that call for vodka or spirits should be avoided entirely, because you need a high-proof liquor to get the right concentration of alcohol by volume. That's because most liquor is mixed with water, so if you mix an 80-proof vodka (which is the standard proof) with aloe, you'll have hand sanitizer that contains roughly only 40% alcohol.
The alternative is to wash your hands. As the CDC and WHO continue to suggest, washing your hands with soap and water for around 20 seconds is one of the best ways to protect yourself from getting sick right now. You should also avoid touching your face if you can, as the virus can be transferred into the body if you've been in contact with someone who's infected.
"There is no recognized therapeutic against coronaviruses," said Mike Ryan, executive director of the WHO Health Emergencies Programme, during a press conference on Jan. 29. That still holds true at present. "The primary objective in an outbreak related to a coronavirus is to give adequate support of care to patients, particularly in terms of respiratory support and multiorgan support."
Notably, because they are viruses, coronaviruses are not susceptible to antibiotics. Antibiotics are medicines designed to fight bacteria and don't do any damage to the SARS-CoV-2 virus. There are no specific treatments for COVID-19 as yet, though a number are in the works including experimental antivirals, which can attack the virus, and existing drugs targeted at other viruses like HIV which have shown some promise.
There have been conflicting messages from the World Health Organization, which appeared to suggest on March 17 to avoid ibuprofen and use paracetamol instead. A Twitter thread on March 18 clarified there are concerns with using the drug to treat fever in people with COVID-19, but the organization is "not aware of reports of any negative effects, beyond the usual ones that limit its use in certain populations"
Those populations include people over 65 years of age and those suffering from conditions such as asthma, high blood pressure and liver or kidney problems. An article in The Lancet on March 11 showed the expression of the ACE2 receptor on human cells -- which the coronavirus uses to get inside and replicate -- may be increased due to ibuprofen use.
Mixed messages and misinformation have been spreading online in regard to ibuprofen use so it's important to remember to check in with official health sources like the WHO. The BBC, speaking to British health experts, notes it's probably best to stick to paracetamol as a first choice.
In developing a vaccine that targets SARS-CoV-2, scientists are looking intensely at the spike proteins. These proteins, which are present on the surface of the virus, enable it to enter human cells where it can replicate and make copies of itself. Researchers have been able to map the projections in 3D, and research suggests they could be a viable antigen -- a fragment that stimulates the human body's immune system -- in any potential coronavirus vaccine.
The protein is prevalent in coronaviruses we've battled in the past, too -- including the one that caused the SARS outbreak in China in 2002-03. This has given researchers a head start on building vaccines against part of the spike protein and, using animal models, they have already demonstrated an immune response.
Notably, SARS, which infected around 8,000 people and killed around 800, seemed to run its course and then mostly disappear. It wasn't a vaccine that turned the tide on the disease but rather effective communication between nations and a range of tools that helped track the disease and its spread.
"We learnt that epidemics can be controlled without drugs or vaccines, using enhanced surveillance, case isolation, contact tracking, PPE and infection control measures," MacIntyre said.
You may also be considering buying a face mask to protect yourself from contracting the virus. You're not alone -- stocks of face masks have been selling out across the world, with Amazon and Walmart.com experiencing shortages. Reporting from Sydney in January, I found lines at the pharmacy extending down the street.
That said, the US CDC in March revised its official guidelines for wearing a face covering in public settings. Due to a shortage of personal protective equipment across the country, some have even turned to making their own face masks -- what's the advice here? CNET's How To team has put together a complete guide on whether to wear a face mask or face covering and the exact recommendations that need to be followed.
Life in lockdown: Guides for your coronavirus quarantine
CNET's How To team has been hard at work collating resources for those of us under shelter-in-place orders. We have a huge number of guides that speak to exercising, cooking and what you should do if you're in lockdown.
As the virus spreads, it's easy to get caught up in the fear and alarmism rampant across social media. There's misinformation and disinformation swirling about the effects of the disease, where it's spreading and how. Experts still caution that the virus appears to be mild, especially in comparison with infections by other viruses, such as influenza or measles, and has a markedly lower death rate than previous coronavirus outbreaks.