The WHO said Friday global production of the swine flu vaccine will fall short this year. ((Keith Srakocic/Associated Press))

Global production of vaccines to protect against swine flu will be "substantially less" than the previous maximum forecast of 94 million doses a week, the World Health Organization said Friday in Geneva.

That means the number of doses produced on an annual basis will fall short of the 4.9 billion doses the WHO previously hoped could be available, said spokesman Gregory Hartl.

Lower production levels stem from production problems, as well as the fact that some manufacturers are still turning out vaccines for seasonal flu, he said.

The WHO has stated that ideally all 6.3 billion people in the world should receive at least one dose of vaccine against the pandemic strain of swine flu, also known as H1N1.

With files from The Associated Press