So far, even the specialists who study the coronavirus might not be able to answer many of the questions that we can ask about the coronavirus. However, some answers are beginning to emerge from practice.
Can I get infected a second time?
Unfortunately yes. The details of such cases are now being studied by specialists.
Is the disease easier or more severe the second time?
Unfortunately, re-infection is not always easier. There are examples when the disease was more severe the second time around. Why this happens is unknown.
Do re-infections occur often?
The proportion of re-infections out of the total number is also unknown. The described examples of re-infections are very few and it is still difficult to draw statistical conclusions based on them.
Does this mean that immunity is not developed? Will immunity from vaccines last long enough?
How long immunity to the coronavirus lasts in most people after directly catching the disease and how long immunity will last when vaccinated are two critical issues that, first of all, will determine the development of the pandemic. There is still no answer to this either.
That is, we do not know anything about immunity?
We know something. There are results from animal experiments, analysis of other viral infections, mass antibody testing in thousands of people, and analysis of the structure of viral proteins. Taken together, the data that is available to date suggests that most people are likely to develop protective immunity – and it will persist for at least many months.
Why has the virus recently been causing such a large number of infections, and what could be done to reduce it?
This question can be answered by the results of one of the studies. American scientists have built a mathematical model for the spread of COVID-19 and proved that cases of mass infection play a critical role in the transmission of the virus. If they were not there, the incidence rate would be much lower. (The results of the study are published in the journal Proceedings of the National Academy of Sciences.)
Experts from the Massachusetts Institute of Technology (MIT) studied about 60 cases of super-proliferation – episodes in which one person infected many other people with the SARS-CoV-2 virus and based on this analysis, they developed a mathematical model for the transmission of the new coronavirus infection.
Modelling results show that mass contagion events are much more common in the current pandemic than would be expected from the normal statistical distribution commonly used in epidemiology. From this, the authors conclude that limiting gatherings and large gatherings can significantly reduce infection rates.
For the SARS-CoV-2 virus, the base reproduction rate is about three. This means that, on average, every infected person transmits it to about three other people.
However, this number varies greatly: some people do not transmit the disease to anyone, while super-distributors can infect dozens of people.
Researchers have identified super-spreaders as people who have transmitted the virus to more than six other people. Using this criterion, the scientists analysed the statistics of 45 mass infection events during the current COVID-19 pandemic.
These studies have shown that events in which 10 to 100 people are infected at the same time occur much more often than we expected, and provide insight into how the ongoing pandemic can be controlled. One way is to prohibit gatherings of more than ten people.
Simulations have shown that if we exclude from the scenario super-spreaders with ten or more contacts, the transmission of the virus will stop.