Hello! Thanks for calling [LinkedPhone’s Customer Success Team]. We are currently helping other customers achieve their goals and want to do the same for you! Please leave a message with your name, number, and a brief description of how we can serve you. We promise to return your call [before close of business today]. In the interim, you can also check out our website at [linkedphone.com] for helpful answers to our most common requests. Thank you.
If you've still got a legacy voice system, meaning an on-site PBX with analog phones, then your only real COVID response will be call forwarding to your employees' home phones. That may or may not be acceptable to your employees, especially since these days many of them won't have an analog phone available, which means you'll need to do your forwarding to a personally-owned mobile phone.

“Good afternoon. You have reached the office of [your name]. I will be out of the office beginning on [date] and will be returning on [date]. Please leave a brief message with your contact information, and I’ll be sure to get back to you as soon as I return on [date]. If this is an emergency or you need to speak with someone before I return, please contact [name of colleague/supervisor], [their job title], at [their phone number].”
A voicemail greeting is a simple message that plays before callers leave a message. It may play either when you don’t answer or if your phone is off. A professional greeting may encourage people to leave messages, which in turn makes it easier for you to get back in touch. Keeping that communication open and efficient may lead to better business relationships. It also helps you put forth a professional image for your business.