The head of the Nigeria Centre for Disease Control (NCDC), Chikwe Ihekweazu, said nearly 2,000 cases had been reported since the first in the northwestern state of Zamfara.
"We currently have 1,966 suspected cases across the country; 109 of those, have been laboratory confirmed. There have been 282 deaths," he told a news conference in Abuja.
Zamfara and the neighbouring states of Sokoto, Katsina, Kebbi and Niger have been hit hardest by the disease. Most of the dead are children aged five to 14.
"We are in the middle of significant response in each of these states to minimise the impact of meningitis among our people," he said.
But Ihekweazu said the type of meningitis C strain responsible for the outbreak was not common in Nigeria and there was a "limited stock" of vaccine worldwide.
The World Health Organisation, which manages the stocks, has delivered 500,000 doses for a vaccination programme to start in Zamfara on April 11, he added.
Another NCDC official described the shortage as "major".
"For Zamfara state alone... It is estimated that about three million doses of vaccine will be required," the official added.
A team was working to determine the actual number of doses required to contain the spread of the disease, which has hit 15 of the country's 36 states and the Federal Capital Territory.
Meningitis is caused by different types of bacteria, six of which can cause epidemics.
It is transmitted between people through coughs and sneezes, and facilitated by cramped living conditions and close contact.
The illness causes acute inflammation of the outer layers of the brain and spinal cord, with the most common symptoms being fever, headache and neck stiffness.
Nigeria lies in the so-called "meningitis belt" of sub-Saharan Africa, stretching from Senegal in the west to Ethiopia in the east, where outbreaks of the disease are a regular occurrence.
More than 13,700 people were infected and over 1,100 died in an outbreak in Nigeria and neighbouring Niger in 2015.