People warned they will face restrictions if they are not fully immunised against Covid.
A warning in Zimbabwe that people will face restrictions if they are not fully immunised against Covid-19 sparked a rush to vaccination sites struggling to meet surging demand.
Residents queued for hours, some starting to line up as early as 4am local time to secure a spot.
"The numbers for people intending to get vaccinated are still high," Linos Dhire, spokesman of Zimbabwe's main public hospital Parirenyatwa, said on Monday.
"We are trying to manage the crowds," he said.
Pressure has piled up on the already buckling system since the government late last month declared that only fully vaccinated vendors would be allowed to trade at tobacco and cotton markets.
The state-owned grain marketing company last week issued an ultimatum for its workers to get vaccinated by the end of July after saying that it would buy only from immunised farmers.
In the capital Harare, resident Molline Makokove, 38, went to Parirenyatwa hospital after her neighbourhood clinic ran out of vaccines.
"When I went back for my second dose, the queues were too long so I left," she said, adding that when she returned a few days later "I was told the second dose was not available."
Another resident, 29-year-old Miriam Tuwe, said she had to wait five days and queue for hours for her first injection.
Others complained of being unable to get a jab despite booking slots ahead of time.
Just over one million people in Zimbabwe have received a first dose out of a population of 14.8 million.
President Emmerson Mnangagwa warned at the onset of the vaccine rollout that those who refused the shots would lose out on some public services.
Zimbabwe has recorded more than 83,800 Covid cases and at least 2,600 deaths to date.