The Southern DHB says essential home and community support services will be prioritised as it prepares for months with lower staffing levels in the wake of the vaccine mandate.
No one can work in healthcare unless they have had at least one dose of the Covid-19 vaccine or are exempt from the government mandate.
The Southern DHB said it was unclear how many home and community support staff had chosen not to be vaccinated and what impact that would have on services.
Its community services general manager Glenn Symon said affected clients would be contacted by their contracted providers.
"Due to the mandatory vaccination order, which has been legislated to keep our population safe and allow our health system to continue to function, a number of health and disability support workers have chosen not to be vaccinated and as a result will not continue their jobs," Symon said.
"Until our workforce is able to recover, which may take a number of months, we will need to prioritise those supports which are essential to keeping our population safe at home.
"This may mean reducing or stopping household management services and reducing the number of visits to some clients."
The DHB was also experiencing higher than historical sick leave as staff were staying at home when they were unwell.
"As replacement workforce is not readily available, providers may need to reduce services commensurate with our workforce."
Those receiving home-based supports were urged to contact their care provider to discuss their needs and their carer's ability to meet them during this time.
"We appreciate this is a disruption, and that providers are working hard to recruit to fill vacancies in their services.
"We look forward to returning to our usual service delivery as soon as possible, and thank everyone for their understanding at this time."