Companies are acting where government is not and pushing workers to get the jab to get the job.

Driving the news: The share of job postings on Indeed requiring vaccination has jumped 90% in just the last month.

The big picture: Vaccination rates in the U.S. are climbing, but hesitancy remains high in certain places. And the Delta variant is foiling companies' return-to-work plans.

• Now, it's not just front-line jobs at restaurants and shops requiring vaccination. Postings for jobs in software development, marketing and sales are mandating that applicants have the shot too.

What's happening: At the beginning of the year, there were basically zero office jobs asking workers to get the vaccine. But even if workers are 100% remote, they'll have to come on-site at some point to meet with colleagues — and firms don't want to take risks.

And even though the overall number of job postings requiring vaccination is still quite small — just about 1,200 per 1 million postings — they're increasing at a rapid clip. "This is incredible growth," says Indeed economist AnnElizabeth Konkel.

• The share of software development jobs postings requiring vaccination has skyrocketed 12,400%, from a minuscule 3.5 per million to 438 per million.
• Marketing jobs have seen an 11,100% jump to 1,110 per million, and sales a 4,100% increase to 374 per million.
• Big companies that are now requiring proof of vaccination — at least to come into the office — include Google, Facebook, Netflix, Disney, Morgan Stanley, Lyft and The Washington Post.

Even jobs that already tended to require vaccination — like those in education, retail and hospitality — are doing so at even higher rates.

The bottom line: This is yet another example of companies acting like governments.

• Even if cities, states or the federal government choose not to mandate vaccination, firms can throw their weight around and effectively set policy by requiring it for their employees or customers — or both.