Low cost ukuleles are made across Asia. China is one of many manufacturing countries.There will still be a good supply of low cost ukuleles available. The planet has become so dependent on China, this wont be true for all products, some retailers are going to run out of product and go broke because the supply chain is broken while the factories are closed.
The Made in China brands like Mahalo and Kala and Ohana are well known, but they are not the only low cost ukuleles available. Indonesia, Taiwan, Korea, Thailand, Vietnam, etc all have ukulele making facilities. No doubt since they are competitive for market space, they will be happy to take up whatever is lost by China. You may just see different brands in your local shop. The massive range of Fender ukuleles are made in Indonesia, the broken supply chain from China may see Fender take up more ukulele space in your local shop. for example?
So far I have not seen any evidence that the virus can be transmitted to a human from a piece of wood. In fact the authorities say that the best way to protect against getting the virus is to simply wash your hands and face, and keep the germs away from your mouth and nose. If your ukulele is exposed to any serious germs and they stay on the wood, you will get sick if you get the germs on your hands and don't wash them before eating or putting your fingers in your mouth. So where have you been today with your ukulele, what germs are already there lurking, why aren't you protecting yourself against them already?
It is amazing how ignorant some people are. The COVID19 name was implemented days ago. You really need to start reading the health literature if you have to ask what COVID19 is. If you don't your ignorance may actually make you very sick or cause death.