There is still much we don't know about novel coronavirus, including how long immunity lasts after you have been infected. We do know that most other viruses that cause upper respiratory tract infections, like the flu and other types of coronavirus, that one is immune for a period of time, but it differs for how long.
Based on current knowledge about novel coronavirus as well as how the epidemic is developing, there is nothing that implies that there is a significant problem with people being re-infected.
If you survive coronavirus once, can you be reinfected?
There are a few reports so far that individuals who've contracted the disease and been cleared of the virus have tested positive again. So far these seem to be extremely rare —in China they seem to account for less than 0.2% of all infections. Other literature shows that scientists have observed persistent infections of coronaviruses in animals.
We still don't know enough about the virus or about how immunity develops after infection to say much about how this might work. Thus far it seems rare enough not to be alarmed about. And most scientists seem to think errors more likely explain why some recovered patients are testing positive.
What should we expect as spring arrives? Will the warm weather hurt or help our efforts to stop the virus?
A big question scientists are trying to answer is whether coronavirus peaks during the winter and ebbs during the summer, like the flu. If there's a seasonal aspect to the virus, then it also means we have to plan for levels of infection in the Northern Hemisphere to rise rapidly as autumn sets in.
The answer is unclear. A new study that hasn't been peer-reviewed yet suggests that 95% of positive cases globally have thus far occurred between -2 and 10 °C, which could indicate greater transmission in cooler climates.
The prospect of seasonality is already influencing how some countries are approaching the problem. The UK's maligned former strategy to encourage herd immunity assumed in part that the country needed to plan for keeping its health-care system from being overwhelmed by peak caseloads in winter.
Yet so many different variables can influence transmission. We've only known about the virus for a few months and have yet to actually observe what will happen as the seasons change. The virus may just barrel through the summer unimpeded, or it may exhibit stranger behavior in the winter. We need more data to make strong predictions.