Just to give some example here are the number of influenza cases in Hongkong:His point is probably that the covid measures and lockdowns in China have the side effect of preventing people from catching the usual diseases like the flu, which results in a weakening of immune systems against those diseases as well. I'm not sure what the measures in non-lockdown areas are. If everyone in China has to stay indoors and avoid contact with others if they have a slight cough, then I can see it being a valid point.
Here is Australia which has opened up again:
Why Australia’s record flu surge is a bleak omen for the NHS
A sharp and early explosion of influenza has hit the country, signaling that a long-feared, post-pandemic flu revival has arrived
www.telegraph.co.uk
(note the 2021 line at y=0)
From what I have heard from Australia they have had a very nasty last few months, with lots of people getting different viruses back to back. Lots of people getting covid(2x), infuenza, RSV, common cold etc within a few weeks in May, work places with >50% being sick at the same time etc.
This is just some empirical statistics. My guess is that when we have changed our behavior(travel restrictions, social distancing, masking, ventilation etc) to lower spread of the respiratory virus SARS-CoV-2, we also lowered the spread of other respiratory viruses such as influenza. Which seems to follow the data. Hypothetically if we get covid from R=6 to R=1 by restrictions, lots of other viruses R<6 should also disappear.
The longer China persists, the harder the opening up wave will be for them. And they have denser cities, less developed hospitals, less clean air etc. If this happens, at minimum, lots of people in Gigafactory Shanghai will be home sick at the same time.