CIDRAP answers your questions about COVID-19.

Last updated: Dec 3, 2022


About COVID-19

COVID-19 is a respiratory disease caused by SARS-CoV-2 that started a pandemic in 2020 and is still a major global public health threat. SARS-CoV-2 is a coronavirus. Viruses in this family cause SARS, which emerged in 2002, and MERS, which first appeared in 2012. Coronaviruses get their name from their crown-like appearance—"corona" in Latin refers to a crown or garland. 

Current knowledge

COVID-19 has infected billions of people globally and killed tens of millions—more than 1 million in the US alone. And although many people now have at least some immunity via vaccination or infection, they can still get infected, even seriously or fatally. And emerging variants might make antibodies produced by your body's immune system less effective.

COVID-19 (or just COVID) is the disease. SARS-CoV-2 is the virus that causes COVID-19.You may, however, see these terms used interchangeably. Some refer to SARS-CoV-2 as the "COVID-19 virus."

Symptoms can vary widely but often include fever or chills, coughing, difficulty breathing, tiredness, body aches, headache, a sore throat, congestion, runny nose, nausea or vomiting, and gastrointestinal (digestion-related) issues like diarrhea.

Loss of taste or smell can be a hallmark, symptoms, but it has been less common with the currently circulating Omicron variants.

Illness severity can range from mild to extremely severe, with patients struggling to breathe. "Long COVID" (see below) is another concern, in which symptoms can linger for months after the initial sickness.

See CDC: Symptoms of COVID for when to seek medical attention.

In this stage of the pandemic, living with COVID-19 will require some shifts in approach and new goals. It's all about minimizing risks while we attempt to return to a "new normal."

No one knows what the future will hold, but now is the time to improve vaccine acceptance, vaccine technology, drugs, ventilation in buildings, surveillance, reporting, testing quality, and testing capacity. And we need to be prepared for the next large-scale public health crisis.

For more information, read the Roadmap for Living with COVID-19 and listen to The Osterholm Update: COVID-19, Episode 94: The Next Normal (36:00).

People with long COVID have persistent health problems from COVID-19 for months to even years after infection—a real problem for which knowledge is only beginning to build. Documented problems include breathing problems, ongoing cough, "brain fog," muscle soreness, fatigue, loss of taste or smell, insomnia, and a host of other health issues.

Many of the long-haulers or those with persistent symptoms after COVID-19 infection are young, healthy people. This is not a problem limited to people who are high-risk, older, or faced with severe illness or were hospitalized.

For more information, listen to The Osterholm Update: COVID-19, Episode 24: Long-Haulers (20:00) and The Osterholm Update: COVID-19, Episode 88: Vaccines, Variants and Long COVID (47:00). 

Variants of SARS-CoV-2 are naturally mutated strains, and it takes time to know how they will affect the spread of COVID-19, severity of illness, or effectiveness of vaccines. The appearance of variants is not unexpected but is still concerning. More variants are likely to appear.

The most concerning changes are those affecting the spike protein, which are the parts on the virus's surface that our immune systems respond to in order to keep the virus from entering our cells. There are a number of variants that health officials are monitoring. 

For more information, see the WHO page Tracking SARS-CoV-2 Variants.

There is no evidence of seasonality for COVID-19. 

For more information, listen to the Osterholm Update: COVID-19: Episode 56: From Checkers to Chess (10:15) and the Osterholm Update: COVID-19, Episode 62: Untangling the Data (29:00).

There is no reason to think the death counts from COVID-19 are undercounts. There is no evidence that deaths unrelated to COVID-19 have been inappropriately attributed to the disease.

For more information, listen to the Osterholm Update: COVID-19, Episode 22: Pregnancy in a Pandemic (23:00) 

Preventing the spread

Like most respiratory diseases, COVID-19 spreads quite easily, because SARS-CoV-2 viruses travel through the air.

There is strong evidence that people contract COVID-19 from aerosol exposure—meaning via tiny particles that can travel long distances when a person coughs, talks, or shouts. Transmission via larger droplets—such as via sneezes—can also occur.

Many of the people who transmit SARS-CoV-2 do so before they have symptoms, when they're not yet sick, or potentially when they're completely asymptomatic (have no symptoms).

For more information, listen to the Osterholm Update: COVID-19, Episode 11: Driven by the Data (17:00). 

If you have the opportunity to get vaccinated, take it now. It is important to be fully vaccinated, which means all of the doses available for your age and immune system status. See the Vaccination and Immunity section below.

In addition, stay home when sick, and get tested if you have COVID-19 symptoms, and retest often. And wear an optimal face covering, such as a well-fitting N95 of KN95 respirator (see the next section), when around others, especially in poorly ventilated buildings.

The spread of COVID-19 is a function of distance, duration, and air circulation. Avoid the three C's: closed spaces, crowds, and close contact. 

For more information, listen to The Osterholm Update: COVID-19, Episode 94: The Next Normal (47:30) and The Osterholm Update: COVID-19, Episode 101: Class in Complicated Times (37:00)

When wearing a face covering, wear one that fits over your nose and snugly around your mouth. Ideally, wear an N95, KN95, or respiratory protection of a similar caliber.

Wearing a face covering is not permission to get close to others or go into crowds. It is merely an added layer of protection for both the wearer and others. Cloth masks and face coverings likely do not offer the same degree of protection as physical distancing, isolation, or limiting personal contact time.

For more information, listen to The Osterholm Update: COVID-19, Episode 64: Straight Talk (52:30) and the Osterholm Update: COVID-19, Special Episode: Masks and Science 

Maintaining separation between people may reduce transmission. The 6-foot rule is based largely on preventing disease spread by limiting exposure to droplets from an infected person—as when he or she sneezes. The science is unclear if 6 feet is sufficient to prevent the spread of COVID-19, although evidence suggests that 6 feet is not enough, and 3 feet is certainly not enough.

A key component to transmission is that virus-containing aerosols (tiny particles much smaller than droplets) can travel well beyond 6 feet. Being much lighter than droplets, they can remains suspended in the air for long periods. Which is why wearing respirators over your mouth and nose is important (see above section).

Vaccination and immunity

It's far better to get the vaccine. We're not learning new information about whether you should or shouldn't take the vaccine—it's overwhelmingly clear that you should. The risk from natural infection with COVID greatly outweighs any slight risk from COVID-19 vaccines.

We are continuing to learn about the effectiveness of COVID-19 vaccines with different variants that emerge and how best to use these vaccines. We are not suddenly going to learn about new safety problems. 

Also, COVID-19 infections brings with it the risk of "long COVID"—having symptoms potential for months or years after getting infected (see above).

For more information, listen to The Osterholm Update: COVID-19, Episode 64: Straight Talk (37:00).

There are four vaccines approved for use in the United States—made by Moderna, Pfizer/BioNTech ("Pfizer," for simplicity), Johnson & Johnson, and Novavax. All of the vaccines appear to offer impressive protection against severe illness and death, while having no serious safety concerns. 

Bivalent boosters are two-strain vaccines and are the most updated versions. They contain the original SARS-CoV-2 strain plus an Omicron component to protect against the most current strains.

The US Centers for Disease Control and Prevention (CDC) recommends that people ages 5 years and older receive a bivalent booster if it has been at least 2 months since their last COVID-19 vaccine dose, whether it was part of a primary series or an original monovalent (one-strain) booster.

The Pfizer bivalent booster is authorized in the US for anyone 5 years and older, while the Moderna version is approved for those 6 years and older.

For more information:

CDC: Stay up to date with COVID-19 vaccines including boosters

US Food and Drug Administration: COVID-19 bivalent vaccine boosters