Netizens have rallied against plans in Beijing to only give the A/H1N1 vaccine to people in the city with permanent residency, or hukou.
The municipal health bureau announced on Friday it would be the first city to roll out its inoculation program to include all 12 million registered residents between Nov 16 and Dec 13.
However, the program excludes anyone over 60, while non-hukou residents only qualify if they work for important service departments.
"It's unfair," wrote one netizen in response to a comment on sina.com.
"The criteria for getting the vaccination should be risk, not hukou," said another on chinadaily.com.cn.
However, a handful of netizens were in support of the decision. One wrote: "It's good as scientists have warned that everyone is susceptible."
Officials with the Shanghai health bureau, meanwhile, said they have no plans to copy Beijing's hukou policy.
"We will continue to focus on priority groups, such as the young, seniors and chronically ill, rather than a cover-all approach," said Xu Jianguang, director of the Shanghai health bureau. "Vaccinating everyone in the city is unnecessary."
The nation's vaccination program, launched in September, aims to cover 65 million people on the mainland by the end of year. More than 7 million have already received shots, said the Ministry of Health.
But due to limited availability, most of the 390 million people considered "high risk" are still waiting.
Beijing planned to inoculate 2.1 million people by year end but is still short 800,000 doses of the vaccine.
As of Saturday, seven domestic companies had produced more than 39 million doses, said the ministry.
The World Health Organization last week warned the virus is on rise in China, which has recorded almost 55,000 infections and 16 deaths.
Local officials log reports about exact inoculation plans, including priority targets and numbers, with the central government before getting supplied of the vaccine. However, funds for the shots come out of local authorities' budgets.
For poor regions, the government has vowed to help finance the vaccine to ensure the vulnerable are protected for free.