Medical experts on Friday warned that patients who had recovered from the virus were still at risk of being infected again, and said people should avoid any mass gathering, even dancing in public parks and squares – a popular activity for exercise in China.
Zhan Qingyuan, head of infectious diseases at the China-Japan Friendship Hospital, said in a press briefing on Friday that people who had already had the virus would have developed antibodies but should remain on alert so they did not get ill again.
“The antibodies may not remain for a long time, so there is still a risk that these recovered patients will be infected again,” Zhan said. “They should continue to keep themselves protected.”
https://www.scmp.com/news/china/soc...-deadly-day-hubei-record-high-42-patients-die
Can any of our medical field members shed some light on this? I assume high levels of antigen-specific antibodies don't stick around forever since that would have a high carrying cost. But for example, how long would it take, ballpark, to drop sufficiently low enough that one could get reinfected by the same strain of of influenza virus?