To grow the virus and inactivate them by chemical reagents is the standard setup for (older) influenza vaccine systems that are egg- or cell-culture-based. From such a setup whole-virus- or subunit vaccines can be derived.

To produce a vaccine, you will need at least:

• Vaccine (or at least a rough idea what your vaccine will be going to look like)
• Large scale production process (which is not the same as a bench scale process)
• Raw materials
• Facility (see below)
• Staff (see below)
• A working quality system (including an ok from the regulatory agencies)

In biopharmaceutical production you have two kind of extremes in the facility design:

• "Stainless steel" facility: This is usually the option if you are going to produce the same product forever. It needs a higher upfront investment but comes with lower operating costs. If you take care of such a facility you should be able to use it for a long time. Construction time should be higher than for the option below, but will depend highly on the exact setup.
• "Single use" facility: This facility design is sometimes referred to as a "ballroom" design because it just comes with the clean room and the needed media (e.g., water, gas, etc.) and uses single-use equipment for the production itself (i.e., plastic bag, tubing, etc.). This setup needs less upfront investments and has higher operating costs (usually due to the expensive single use equipment). There are also production systems which are built into containers.

Of course, everything between those two designs is possible. Both types can be designed to produce multiple products which is referred to as a "multi-product facility". Depending on the automation grade you will need more or less staff with more or less training and experience. For the ramp-up of the facility and for ongoing troubleshooting you will need (highly) educated stuff.

The vaccine production systems can be roughly classified into these variants:

• Egg-based: Egg gets infected with virus, virus particle or parts of it are used for the vaccine.
• Cell-culture-based: The same as above, but you infect cells.
• Microbial/insect-based: Usually used to express subunits of the vaccine and no entire virus particles. Can be also used for DNA vaccines?
• (Fully?) synthetic: Nucleic acid- (i.e., RNA, DNA) or poly-saccharide-based vaccines?

These outlined systems are quite different, and, therefore, the facilities will look different. However, a well-designed multi-product facility should be able to cover a wide range of the possible vaccine types because basic fluid handling and a lot of other steps are similar.

The most similar historical equivalent I can think of is the penicillin production, although there the circumstance where quite different.

Vaccines are one of the most cost-effective medical preventive measures but usually the margins are thin. This is why the investments in such products has not seen the levels of treatments of civilization diseases, e.g., cancer or diabetes.

Edit: Added large scale process to the points at the beginning.

No direct prediction from my side but a link to a report: https://www.mckinsey.com/business-functions/risk/our-insights/covid-19-implications-for-business

The full PDF report (linked on the website) has on page 15 a overview of possible outcomes that could be a basis for discussion.