I’m happy to hear that I was able to answer your questions, thank you for letting me know :)

For the next 2 questions, here are my answers:

1. The close contact (i.e., close relative or friend) will be categorised as “asymptomatic” covid-positive patients. That is, they are infected with the virus and can transmit the virus, but they do not show any symptoms. In this case, there can be two reasons:

(i) the viral load during initial exposure is low. For example, they might have gotten the virus through contaminated surfaces or objects (fomites) instead of through direct respiratory droplets that are carrying the viruses. Since viral loads from fomites are relatively low, there may not be enough viruses to cause any harmful effect to the host. And given the low numbers, the immune system will be able to clear the virus from the body quickly without any complications.

(ii) The immune system is working properly. This can be because their immune system is naturally effective or they may have been vaccinated and have acquired specific memory B and T cells against the virus.


2. Indeed the human body consists of many bacteria (microbiome) and many more virus (virome). However, most of the virus inside the human body are called bacteriophage—a virus that infects bacteria. These bacteriophage seem to infect only bacteria and doesn’t seem to harm the human cells. However, it is possible for these bacteriophage to infect and kill the “good” bacteria in our body. And since the good bacteria contributes to our immune system, the lack of these bacteria will then weaken our immune system and make us susceptible to infections. I’m not sure if humans do harbour any virus from the coronavirus family as I have not managed to find any info on that.

As to whether they proliferate only when our immune system is in a weakened state, I don’t believe so; because virus needs to proliferate in order to survive. Hence, they will constantly proliferate as long as they found a suitable host.

Again, these are all based on my understanding and I may be wrong.