This is a business continuity issue. Some of the other answers are focusing on how to approach the idea of working from home for yourself, but that isn't the real problem here.
You say your company is a relatively large organisation, and it has in-house IT (you, and your department). Therefore it will have someone in charge of disaster recovery and business continuity already working on this. They have probably done or are currently doing a risk assessment. So far they haven't determined the risk to the business very high, but that might change.
The overall risk is not only to you, or your coworkers, but to the business (and in the wider sense the overall economy). Let's play this through, from the view of the company.
Assume half the staff gets ill. They don't have to be seriously ill, just unable to work. If 250 of 500 people can't go to work, chances are the company will not produce any products or services in that time. SLAs with customers will not be fulfilled, leading to penalty payments. Customers will leave. If there is production, machines need to be stopped, which is costly (think car factory). All the running costs, in particular salaries and buildings and things like this will still have to be paid, but there is no revenue. That means the company will lose money fast. And with its liquidity it will lose the ability to pay your salary. You will lose your job, and the company will fold.
A recent example of this already happening is Flybe, where CoVID-19 has been named as something like the last drop (credibility of this source unclear).
Now what does that mean for you? It's hard to say. The risk assessment isn't your job, but you can take precautions.
No-one will blame you for voicing your concerns in this situation, even if that is not part of your job. If you have already got infrastructure in place to work from home, use it. They are likely not going to question you. In particular if your commute involves busy public transport, there are lots of good arguments to not go to work. The main argumentation is not to keep yourself from getting sick, but from spreading the virus (or other illnesses that someone else might contract in addition to the virus because their immune system is weakened) into the office.
My suggestion is to ask your manager about business continuity plans. Looks at what companies around you are doing. If you have a spouse you live with, has their company sent everyone home? These are good arguments to give them.
Your company's business continuity team might be well prepared and currently executing risk mitigation, or it might not. In either case, they will appreciate that some people are aware and conscious of the situation.