COVID-19 Disease

Last Reviewed
January 18, 2021

COVID-19 Disease 

Since 2019, the US Centers for Disease Control and Prevention (CDC) and the World Health Organization (WHO) have been closely monitoring the worldwide outbreak of a novel coronavirus known as SARS-CoV-2, which is causing the novel coronavirus disease 2019 (COVID-19) in humans.

COVID-19 is a new disease caused by this coronavirus that has not previously been seen in humans, says the CDC. Many types of human coronaviruses, including some that commonly cause mild upper-respiratory tract illnesses.

People with COVID-19 disease have reported a wide range of symptoms that may appear 2-14 days after exposure to the SARS-CoV-2 virus. Based on currently available information, older adults and people with underlying medical conditions are at higher risk for severe illness from COVID-19, says the CDC. Researchers have identified both diabetes and kidney disease were accurate predictors of serious outcomes in older hospitalized patients.

COVID-19 Preventive Vaccines

The COVID-19 vaccine development landscape includes innovative platforms such as nucleic acid, virus-like particle, peptide, viral vector, recombinant protein, live attenuated virus, an inactivated virus approaches, says the FDA.

“We are committed to expediting the development of COVID-19 vaccines, but not at the expense of sound science and decision making. We will not jeopardize the public’s trust in our science-based, independent review of these or any vaccines. There’s too much at stake," says Stephen M. Hahn, M.D., FDA Commissioner.

On December 26, 2020, the CDC issued the following statement: 'Adults of any age with certain underlying medical conditions are at increased risk for severe illness from the virus that causes COVID-19. mRNA COVID-19 vaccines may be administered to people with underlying medical conditions provided they have not had a severe allergic reaction to any of the ingredients in the vaccine.'

'People with HIV and those with weakened immune systems due to other illnesses or medication might be at increased risk for severe COVID-19. And people with autoimmune conditions may receive an mRNA COVID-19 vaccine. They may receive a COVID-19 vaccine. However, they should be aware of limited safety data.'

To review a listing of experimental COVID-19 vaccine candidates, please visit PrecisionVaccinations.

COVID-19 Disease Symptoms

The most common symptoms of COVID-19 disease are fever, tiredness, and dry cough. Some patients may have a loss of smell, with varying combinations of additional symptoms such as confusion, abdominal pain, and shortness of breath, which are not widely known as COVID-19 symptoms, yet are hallmarks of the most severe forms of the disease.

The CDC announced on March 3, 2020, that a significant portion of individuals infected with the SARS-CoV-2 coronavirus lack symptoms (“asymptomatic”) and that even those who eventually develop symptoms (“pre-symptomatic”) can transmit the virus to others for several days before showing symptoms. 

This means that the virus can spread between people interacting nearby—for example, speaking, coughing, or sneezing—even if they do not exhibit symptoms.

On April 25, 2020, the CDC announced the expansion of the COVID-19 disease symptom list to include Fever, Cough, Breathing difficulty, Chills, Muscle pain, Headache, Sore throat, and a new diagnosis loss of taste or smell.

On July 17, 2020, researchers from King’s College London revealed that they found six distinct ‘types’ of COVID-19, each distinguished by a particular cluster of symptoms.

A cross-sectional study of children hospitalized with COVID-19 in China, published by JAMA on August 26, 2020, presented a series of onset symptoms, including ocular manifestations, such as conjunctival discharge, eye rubbing, and conjunctival congestion. This study found that 23% of hospitalized COVID-19 patients had conjunctival discharge, congestion, and eye rubbing.

On October 1, 2020, a new study suggested that recent loss of smell is a particular COVID-19 symptom and should be considered more generally in guiding case isolation, testing, and treatment of COVID-19. This data indicated greater potential importance of anosmia, as fever was present only in 42.7% of individuals testing positive, versus anosmia being present in 64.6% (34.7% of those not suffering from fever).

A study published by The Lancet on November 3, 2020, confirmed that anosmia is the single most predictive symptom of a positive swab test across different age groups, with odds ratios ranging from 13.67 (95% CI 11·65–16·02) for the older group to 20.86 (18·62–23·4) for the younger group.

Additionally, the CDC says if you develop any of these emergency warning signs, seek medical attention immediately. These symptoms may appear 2-14 days after exposure to the SARS-CoV-2 coronavirus.

People at Risk from COVID-19 Disease

COVID-19 is a new disease, and scientists are still learning how it spreads. Someone who is actively sick with COVID-19, or infected with the SARS-CoV-2 virus, can spread the illness to others, says the CDC. Recent studies suggest that recovery from one SARS-CoV-2 infection might not protect a person against a second infection.

People can catch the COVID-19 disease from others who have the SARS-CoV-2 virus. Older people, and those with underlying medical problems such as obesity, high blood pressure, heart problems, or diabetes, are more likely to develop serious illnesses.

And, pregnant women can become infected with SARS-CoV-2 coronavirus and COVID-19 disease.

Furthermore, children of all ages, including infants, appear susceptible to COVID-19 disease because the SARS-CoV-2 coronavirus is novel, which means infants cannot obtain protective antibodies from their mothers. However, researchers from the American Academy of Pediatrics (AAP) and the Children's Hospital Association compiled data from state health departments to confirm that children can contract COVID-19, although severe disease appears to be very uncommon.

As of September 10, 2020, the AAP data indicated 0.01% of child cases in the USA resulted in death.

On October 6, 2020, the CDC published an update to reflect recent data supporting an increased risk of severe illness from the virus that causes COVID-19 among adults with COVID-19 who have obesity, who have overweight, or who smoke or have a history of smoking.

Additionally, 'rogue antibodies and gene mutations might explain the differences in some severe COVID-19 cases', said Francis S. Collins, M.D., Ph.D., the 16th director of the National Institutes of Health (NIH).

Recent NIH-funded studies suggest that one reason some otherwise healthy people become gravely ill may be previously unknown auto-antibodies in their immune systems, which hamper their ability to fight the virus. And these new findings in hundreds of racially diverse people with life-threatening COVID-19 found a small percentage of people who suffer the most severe symptoms carry rare mutations in genes that disrupt their antiviral defenses.

Additional clinical evidence suggests a person's blood type may play a role in COVID-19 susceptibility. A study from Denmark published on October 14, 2020, found blood group O is associated with a decreased risk for contracting SARS-CoV-2 infection. And a second study found COVID-19 patients with blood group A or AB appear to exhibit a greater disease severity than patients with blood group O or B.

And a third study published on November 24, 2020, based on a cohort of 225,556 people in Ontario, Canada, found the O and Rh− blood groups may be associated with a slightly lower risk for SARS-CoV-2 infection and severe COVID-19 illness. Of the study participants infected with the new coronavirus, the lowest unadjusted probability of SARS-CoV-2 infection was among the O− blood group (2.1%). The highest was in the B-positive blood group (4.2%).

COVID-19 Disease Diagnosis

COVID-19 disease is diagnosed by a healthcare provider when a sample is tested via reverse transcription-polymerase chain reaction (RT-PCR) to determine the presence of viral RNA. Various antibody tests detect if you have an immune response due to past exposure to the SARS-CoV-2 virus.

The US CDC COVID Data Tracker published data indicates there have been over 114 million diagnostic tests, excluding antibody, and antigen tests, performed in the USA to confirm if a person has a SARS-CoV-2 infection during 2020. Overall, this data indicates the USA has a COVID-19 infection positivity rate of 8%, as of October 1, 2020.

COVID-19 Disease and Cardiac Cases

The SARS-CoV-2 has been found to have a marked tropism for the heart and can lead to myocarditis (inflammation of the heart), necrosis of its cells, mimicking of a heart attack, arrhythmias, and acute or protracted heart failure (muscle dysfunction). These complications, which at times are the only features of COVID-19 clinical presentation, have occurred even in cases with mild symptoms and in people who did not experience any symptoms.

COVID-19 Disease and MIS-C

Since mid-May 2020, the U.S. CDC has been tracking reports of a multisystem inflammatory syndrome in children (MIS-C), a rare but serious condition associated with COVID-19. MIS-C is a new syndrome, and many questions remain about why some children and adolescents develop it after a COVID-19 illness or contact with someone with COVID-19, while others do not. As of October 15, 2020, the number of confirmed MIS-C cases in the USA surpassed 1,097, with 20 related fatalities.

Furthermore, a study published by the JAMA on November 23, 2020, found that the number of diagnosed cases of Kawasaki disease (KD) was reduced in 2020, suggests that patients presenting with MIS-C likely do not receive diagnoses of KD, which should not be used as a proxy for this new entity.

COVID-19 Long Term

Most COVID-19 patients experience mild symptoms and typically recover within a few weeks. However, as the pandemic continues to unfold, the medical world is learning that many organs besides the lungs are affected by COVID-19. Some patients continue to experience symptoms that can last for weeks or even months after recovering. 

According to the US CDC, multi-year studies have investigated the long-term effects of COVID.

Coronavirus FAQs

Note:  Content sourced from the CDC, WHO, various governments, news agencies, social media networks, and the Precision Vax news network. All of the posts have been review by medical professionals, such as Dr. Robert Carlson.