A year after the emergence of swine flu, US health authorities and laboratories say the pandemic illustrated the need for new vaccine production techniques that are faster and more reliable.

At present, vaccines like the one used against the swine flu are developed inside eggs, into which scientists implant a weakened version of the virus that will grow into a form suitable for inoculation.

But that process is relatively slow and unpredictable, and experts say the future lies in developing vaccines at the cell and DNA-level.

"We have never been in a stronger position to create new and better vaccines," US Health and Human Services Secretary Kathleen Sebelius said this week on the anniversary of the discovery of the A(H1N1) virus.

The swine flu pandemic illustrated the need "to bring the technology of influenza vaccine development and manufacture into the 21st century," said Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, part of the National Institutes of Health.

The US government is now partnering with the private sector and investing billions of dollars into research to foster new vaccine development methods in time for future pandemics, Fauci told AFP in an interview.

He said US laboratories were able to quickly identify the A(H1N1) virus, isolate a "seed" for implantation in eggs and carry out clinical trials.

But despite their speed, they failed to produce the number of vaccine doses expected because growing the vaccine remained so slow.

"It's still a fragile technology, it's subject to vicissitudes that are beyond the control of the people that are making the vaccine," said Fauci. "Unfortunately that's what happened," he added. "We were fortunate that a single dose worked."

He said bringing vaccine development "into the 21st century" would occur in two phases.

"The first phase is to make a conversion from growing viruses in eggs to growing viruses in cells, which is much more reliable, and being able to scale up," he said.

Cell-based development of vaccines is still not a speedy process, Fauci said. But the development of vaccines in eggs can take between six and nine months, and cell-based vaccine development is much more reliable.

Eventually, the second phase of perfecting production techniques will be a move to so-called recombinant DNA technology, where pieces of different DNA strands are combined.

The technology would eliminate the need for scientists to grow the target virus in order to extract a vaccine, speeding up the process to as little as two months, Fauci said.

Informed by its experience with the swine flu pandemic, the US government is now partnering with the private sector to speed the emergence of quicker and more reliable vaccine development methods.

Fauci cited a partnership with Novartis, which has built a plant for the production of cell-based flu vaccines in North Carolina.

"It will be a gradual process," he said. "In the next year or so, you will be seeing some of these recombinant products ready to be used in humans."

Another field of continued research is a so-called "universal vaccine" for influenza.

"That's the Holy Grail," Fauci, adding that it wasn't likely to emerge for another five to 10 years, though he remained hopeful. "I think it's possible," he said.