The DHB said there were no staffing or supply issues affecting the latest figures.
A DHB spokesperson said there was a noticeable surge in demand when the country went into lockdown, and the DHB was seeing a "natural reduction in bookings".
"The reduction in numbers over the past week or so is due to demand from the community," the spokesperson said.
"With regard to forecasts, targets, or 'usual' uptake, it is not possible to give numbers as bookings are coming in all the time – both at a local level to community providers and into the national booking system."
The DHB said its target was to vaccinate 100 per cent of the eligible population.
"At the same time, we are planning new clinics for workplaces, rural areas, particular groups. This work takes place on a daily basis."
Louise Allsopp, senior responsible officer for the Whanganui vaccine rollout, said there was no shortage of vaccines.
"We are running clinics right across the rohe and we have capacity and vaccine, so we are asking people to make a booking and get vaccinated," she said.
"Vaccination is one of the most important tools in our fight with Covid-19, and getting people vaccinated is crucial to easing restrictions and moving the country down alert levels."
As of Wednesday, 38.4 per cent of Whanganui's eligible 12 years-plus population was fully vaccinated, while 29.2 per cent had received one dose.
A total of 32.4 per cent remain unvaccinated.