A Cullybackey meat processing plant has been closed because of Covid-19 cases amongst employees.
Cranswick,a pig processing plant is to shut for a deep clean and for the testing of staff.
The company briefed its workers on Thursday afternoon, with the closure taking effect from 18:00 BST on Saturday.
A company spokesman declined to confirm how many of its 500 staff were involved in the current outbreak, but said staff welfare was the primary concern.
"There has been a recent increase in the number of confirmed Covid-19 cases in Ballymena and the wider region and this has been acknowledged as a community issue.
"As a result of this, we can confirm that a number of colleagues at our Ballymena site have tested positive for Covid-19.
"Working with the Public Health Authority (PHA), we have taken the decision to send all of our colleagues for testing. If the test results are positive, the individual will be required to self-isolate for 10 days; if the test results are negative, the individual will be required to self-isolate for 14 days.
"Therefore, the site will need to temporarily suspend production."
The Public Health Agency said it had made a "number of significant recommendations" to a business in the Mid and East Antrim Council area.
"These include the testing of all staff this week and self-isolation of staff identified as close contacts of cases."
It said testing and tracing was being carried out to identify staff who might potentially be affected to help prevent further community transmission.
It said it would not comment on individual cases to prevent people with the disease being identified or to deter others from coming forward.