The novel coronavirus (SARS-CoV2) belongs to the β genus of viruses and is closely related to viruses that cause the other severe respiratory diseases MERS & SARS as well as some instances of the common cold. COVID-19 refers to the disease this virus causes (so named because it was discovered in 2019…not because it is the 19th coronavirus discovered), not to the virus itself. COVID-19 is an acute, infectious, respiratory disease. While predominantly a disease of the respiratory system (from the upper naso-pharynx to the lungs, it is more accurate to refer to it as a form of pneumonia, rather than as something that sometimes develops into pneumonia. While some recover from the illness fairly quickly, others can take weeks or months to fully recover, and they may suffer from long-lasting symptoms that persist long after their recovery from the initial respiratory illness (…so-called “Long Covid”).
Humans are generally susceptible the virus, though it is believed that it originated in bats. It is believed that people infected by the novel coronavirus are the main source of the spread of the infection, by shedding of the virus into the air around them, through coughing or simply talking.
Unfortunately, asymptomatic infected people can be a source of contagion, as it has been shown that those with no symptoms can still spread the virus. In addition, those with light cases of covid-19 also spread the disease, which is a severe problem, since a mild infections is easily mistaken for a non-contagious condition, such as a sinus allergy, etc. And, while infected persons are the most contagious while exhibiting solid symptoms of the disease, it is likely that they can still spread it before the symptoms become apparent, and potentially for a couple of days after recovery.
The bare virus is not particularly hardy compared to, say, measles virus. However, droplets bearing the virus can survive for as long as several hours in the air, and several days unsanitized surfaces. Based on the current epidemiological investigation, the incubation period is 1 to 14 days, most commonly 3 to 7 days, including a contagious, but asymptomatic period, though the virus may invade susceptible cells that it contacts in less than 12 hours.
While some of the symptoms of COVID-19 are similar to those from influenza (“the flu”), these are different diseases. In fact, it would not be at all unusual for a person to be simultaneously stricken with COVID-19 and influenza, which can be particularly dangerous, especially to older persons, or those with compromised respiration or weakened immune systems. This points to the value of testing for both diseases, as and treatment should account for whichever (or both) disease(s) is/are present or when either disease is masquerading as the other. Similarly, it is valuable to confirm or rule out diseases for which there are tests, which, together with the specific symptoms, can point to other diseases (such as RSV) for which tests are not commonly available.
The main manifestations of COVID-19 include fever, fatigue and dry cough, initially. Nasal congestion, runny nose, sore throat, myalgia and diarrhea are found in a some cases. If the disease progresses in severity, the ability of the body to uptake oxygen becomes impaired and blood oxygen can plummet, sometimes extremely, even with mechanical ventilation and supplemental O2. Ominously, in some cases, the restricted oxygen uptake is not perceived by the person stricken.
This impairment of respiration is caused by either the disease itself, or the body’s reaction to it, through a build-up of a large amount of pus or mucous and a thickening of the walls of the lung alveoli. The disease presents a special danger to older patients and those with preexisting conditions that already compromise lung function. But, persons of all ages have succumbed to the disease.
Also, sometimes seemingly light cases of infection can take a sudden turn for the worse, Also, while it is not considered a disease of the blood, it can spread there. When this happens, the symptoms can increase and damage can occur to the heart, brain and other organs, which can require months (…if ever) for recovery.
While there are therapies, such as monoclonal antibodies, and some steroidal drugs, that can help stave off serious illness, especially if administered early, it can’t be said that there is a 100% effective cure once the disease progresses in severity. Down from the peak of casualties, hundreds of COVID patients still die each week in the USA.
As with other respiratory ailments, vaccine development was a challenge, because these ailments do not induce as strong of an immune response, in the body, as those “bugs” that primarily invade the blood. (In fact, as mentioned above, covid-19 is not considered a disease of the blood…though its effects can be so serious & long-lasting when that does occur. In spite of the problems with developing vaccines for respiratory disease, several vaccines of various types have been developed, and are proving to be effective at either preventing illness, minimizing symptoms &/or improving chances of survival. How effective each vaccine will continue to be is uncertain, as variants of the virus continue to appear…in fact, developing more rapidly than occurs with influenza.
The greater is the occurrence of the virus, the greater will be the occurrence of these mutations. And, until “herd immunity” of as much as 85% of the general world population is achieved, it can’t be said that the pandemic is fully abated.
It should also be mentioned that, because of the nature of the disease, natural immunity, in those who have recovered from covid-19, is not likely to be as strong as immunity induced by vaccines. And, there appears to be no 100% immunity, whether from a vaccine, booster or prior recovery from COVID. In fact, there are many reported cases of people suffering covid-19 disease multiple times. This is likely to occur particularly in the case of new variants. Unfortunately, though the common belief is that subsequent infections are likely to be less severe than the initial one, that is not necessarily the case. In fact, researchers have found that people with COVID-19 reinfections are more likely to suffer organ failure; three times more likely to be hospitalized twice as likely to die.
Thus, while these precautions are “getting old”, the best protections will remain “social distancing” (at least within inside, poorly ventilated, environments); hand-washing (especially before touching the face, nose, mouth or eyes); mask-wearing in close quarters; testing; tracing and at least limited quarantining after exposure. In addition, Newgene-US is investigating the formulation of an affordable nasal mist that some believe can help ward off the virus after it is inhaled, if used promptly.
In any event, it is likely that quarantining, testing and tracing of those who are stricken, are likely to remain the wisest policies indefinitely, until a combination of affordable & effective vaccines; probable annual boosters & antivirals are so common & affordable, universally, that the transmission of the disease, and appearance of variants declines significantly.
Until that occurs (…if it ever does), because we cannot wall off the USA from the rest of the world, we will remain vulnerable to the latest foreign strain or variant to which we are not immune, which is less vulnerable to the current vaccine &/or can cause a reinfection even in vaccinated, boosted &/or recovered persons. In a crowded world, experience has shown that epidemiologists are not crazy when they talk about “the next pandemic” and insist that it is not a case of “IF”, but rather of “WHEN”.
s that cause the other severe respiratory diseases MERS & SARS. COVID-19 refers to the diseases this virus causes (so named because it was discovered in 2019…not because it is the 19th coronavirus discovered), not to the virus itself. COVID-19 is an acute, infectious, respiratory disease. It is more accurate to refer to it as a form of pneumonia, rather than as something that sometimes develops into pneumonia
Humans are generally susceptible the virus, though it is believed that it originated in bats. It is believed that people infected by the novel coronavirus are the main source of the spread of the infection, by shedding of the virus into the air around them, through coughing or simply talking. Unfortunately, asymptomatic infected people can also be a source of contagion, as it has been shown that those with no symptoms can still spread the virus. In addition, those with light cases of covid-19 also spread the disease, which is a severe problem, since a mild infections is easily mistaken for a non-contagious condition, such as a sinus allergy, etc.
The bare virus is not particularly hardy compared to, say, measles virus. However, droplets bearing the virus can survive for as long as several hours in the air, and several days unsanitized surfaces. Based on the current epidemiological investigation, the incubation period is 1 to 14 days, most commonly 3 to 7 days, including a contagious, but asymptomatic period. While some of the symptoms of COVID-19 are similar to those from influenza (“the flu”), these are different diseases. In fact, it would not be at all unusual for a person to be simultaneously stricken with COVID-19 and influenza. In fact, such a simultaneous infection can be particularly dangerous, especially to older persons, or those with compromised respiration. This points to the value of testing for both diseases, as and treatment should account for when both are present or when either disease is masquerading as the other,
The main manifestations of COVID-19 include fever, fatigue and dry cough, initially. Nasal congestion, runny nose, sore throat, myalgia and diarrhea are found in a few cases. If the disease progresses in severity, the ability of the body to uptake oxygen becomes impaired and blood oxygen can plummet, even with mechanical ventilation and supplemental O2.
This impairment of respiration is caused by either the disease itself, or the body’s reaction to it, through a build-up of a large amount of pus or mucous and a thickening of the walls of the lung alveoli. The disease presents a special danger to older patients and those with preexisting conditions that already compromise lung function. But, persons of all ages have succumbed to the disease. Also, sometimes seemingly light cases of infection can take a sudden turn for the worse, Also, while it is not considered a disease of the blood, it can so spread and, when this happens, the symptoms can increase and damage persist for months (…so-called “long-haul” patients).
While there are therapies, such as monoclonal antibodies, and some steroidal drugs, that can help stave off serious illness, especially if administered early, it can’t be said that there is an actual, specific, anti-viral drug for the novel coronavirus exist yet.
As with other respiratory ailments, vaccine development was a challenge, because these ailments do not induce as strong of an immune response, in the body, as those “bugs” that primarily invade the blood. (In fact, covid-19 is not considered a disease of the blood…but, when it does so invade the blood or brain, the effects can be serious, and permanent.) In spite of the problems with developing vaccines for respiratory disease, several vaccines of various types have been developed, and are proving to be effective at either preventing illness, or improving chances of survival. Whether they will continue to be effective as variants of the virus develop, is yet to be seen, but coronaviruses are known to rapidly change over time..
Until “herd immunity” of as much as 85% of the general population is achieved, the best precautions are “social distancing” (especially within inside environments), hand-washing (especially before touching the face, nose, mouth or eyes), mask-wearing, testing, tracing and quarantining, after exposure, for 10-14 days. In fact, it is likely that quarantining, testing and tracing of those who are stricken, is likely to remain the wisest policy indefinitely, until there are common, affordable and highly effective antivirals against COVID-19.
It should also be mentioned that, because of the nature of the disease, natural immunity, in those who have recovered from covid-19, is not likely to be as strong as immunity induced by vaccines. In fact, there are a number of reported cases of people suffering covid-19 disease more than once. And, this is likely to occur particularly in the case of some variants.