The Government spent £239 million on swine flu vaccine, official figures reveal.
The Information Commissioner's Office (ICO) ordered the Department of Health to release the data after it failed to comply with a freedom of information (FOI) request.
The Government has always cited commercial confidentiality as a reason for not disclosing the information, but the ICO ruled it was in the public interest.
Today, the department confirmed it had spent £239 million on the jab up to the end of vaccine deliveries in April 2010.
The money was paid to GlaxoSmithKline (GSK) for its Pandemrix vaccine, and Baxter for Celvapan.
Some 90 million doses were ordered by the UK government, with most of the vaccine supplied by GSK.
In April 2010, the Government announced it had struck a deal with GSK to cancel part of its massive order for the vaccine.
The deal saved the UK approximately one third of the original value of the orders with GSK.
However, there were still many leftover doses. Some of these have been used this flu season after stocks of the seasonal flu jab ran low.
A spokesman for the Department of Health said today: "The Department has released this information in order to comply with the (ICO) decision notice.
"We have gone further than the original request by giving the full information on spend in the interests of transparency and in view of the public interest in this issue.
"We will continue to consider each FOI case on its merits."
The costs relate to the development, distribution, promotion and purchasing of the vaccine, although the department has not been told to disclose how much was paid to each individual company.
In its ruling earlier this year, the ICO said that while the majority of the original FOI request was complied with, the department "failed to provide information around the costs of purchasing the vaccine believing that the information would prejudice the commercial interests of the manufacturers, along with its own commercial interests, and those of other NHS bodies".
However, the commissioner ruled the department should release the purchasing costs because it was in the interests of transparency over public spending.
ICO head of policy delivery Steve Wood said at the time: "The Department of Health must be transparent about the spending of public money at a time when public finances are under considerable scrutiny.
"The information also relates to a public health issue of significant interest to the general public.
"We are however mindful that the manufacturers involved should not be penalised for working in partnership with the NHS and have therefore agreed that the Department was right to withhold information providing a detailed breakdown of the costs associated with both GSK and Baxter."