Coronavirus: The 3 types of symptoms

Coronavirus: The 3 types of symptoms

The manifestation of Coronavirus in individuals is different from case to case, but it can be summarized in 3 categories of people.

Here we will explain how the virus can develop in 3 different situations, identified in 3 cases of individuals, which could be:

  • CASE A: asymptomatic and infected
  • CASE B: symptomatic and infected
  • CASE C: severely symptomatic and infected

We will analyze the evolution of the virus over time, starting from day 0, when the virus enters the body, until the end of its natural life.

We have divided the duration of the infection into phases:



Each of these phases has a variable duration depending on the individual, but for the sake of this hypothesis, we will consider an average of 5 days for the initial phase and of 14 days for the intermediate phase, for each individual.

CASE B: symptomatic and infected individual


Let’s start with the simplest case since it is a situation we are more familiar with. It is a person who, as with the common flu, is infected with the virus on day “zero”.

During the initial stage, the person does not show any symptoms since the Coronavirus is still replicating and has not yet caused enough damage to manifest any symptoms in the affected individual.



During the intermediate phase, the virus is in the phase of maximum expansion, the individual manifests the typical flu-like symptoms, such as fever, cough, cold, mild shortness of breath, fatigue. During this phase, the individual is certainly infectious and is able to spread the virus. The immune system switches on with sentinel cells that are activated to kill the virus by producing increasingly effective antibodies. Gradually, at the end of the intermediate phase, the person’s immune defenses manage to defeat the virus that can no longer replicate itself and it is definitively eradicated.

In the final phase, the patient has recovered: he doesn’t show symptoms and he is no longer infectious because the virus is now gone, therefore he can’t infect other people. The acquired immunity is permanent: the memory of the war won against the virus keeps the defenses ready for a potential second attack, so it is impossible for the virus to be able to infect the individual for a second time.


CASE C: severely symptomatic and infected individual


During the initial phase, the person does not show any symptoms because the virus is replicating and has not yet caused enough damage for any symptoms to appear.

In the intermediate phase, the viral replication in these individuals is wider, symptoms gradually get worse until severe respiratory failure occurs. There is now a need to intervene with supportive therapies, such as the use of oxygen or assisted ventilation techniques. During this phase, the patient is very infectious. The patient may need ICU as well as more serious assistance methods, such as cardio-pulmonary support, which consists of using devices to artificially replace both lungs and heart functions for a limited period of time. In these cases, the duration of the intermediate phase is prolonged until the final outcome.

The final stage can be healing or death.


CASE A: asymptomatic and infected individual

 Let’s now consider the more complex case: an individual who is infected with the virus, but does not experience any symptoms during all stages of viral replication until healing.

During the initial phase, the individual does not experience any symptoms.

Even during the intermediate phase, despite the presence of the virus and its active viral replication, the patient does not present symptoms and leads a normal and active life.

The intermediate phase ends with the patient’s recovery, after which he becomes immune to Coronavirus for life. 

It now seems established that many of these individuals would actually be infectious during all stages of the presence of the virus in their system, which means they are spreading the virus despite having no symptoms. This might be the reason why the virus has started to spread so significantly, and it is not possible to identify these subjects except through specific tests.


Case distribution

After analyzing the 3 ways through which the virus can manifest in individuals, let’s ask ourselves some questions. What is the distribution of the 3 cases in the population? In particular, out of 100 infected individuals, how many cases are in type A, B or C? This is a question we cannot answer. There is data available on the internet, however, how can we be sure to identify the correct proportion of individuals within the 3 case types? Or is it perhaps easier to find B and C cases since they show symptoms, while it is much more difficult to discover type A patients since they initially spread the virus and then heal amongst the population? Every day the data are updated and so is the population of cases A B and C also reviewed. 

Med4Care Marco De Nardin

Marco De Nardin M.D.










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