Less than two weeks after Chinese officials released the genetic sequence of a new type of bird flu, U.S. vaccine experts are well on the way to making a vaccine to protect people against it.
There’s no evidence the H7N9 virus would ever threaten the U.S. It’s been diagnosed in fewer than three dozen people, all restricted to eastern China. People don’t appear to be infecting one another, at least not in large numbers.
But it’s already killed nine of them. Scientists said Wednesday that the virus seems to have been the result of genetic reassortment of wild birds from east Asia and chickens from east China, Xinhua, the official Chinese news agency reported. Still, it doesn’t seem to be making birds sick -- which means authorities don’t have tell-tale die-offs of poultry to warn them when it’s circulating.
And it takes months to make influenza vaccines, so every day may count.
“It puts flu back on people’s minds,” said Dr. Amesh Adalja, an emergency physician at the Center for Biosecurity at the University of Pittsburgh Medical Center.
It’s just the kind of situation that flu experts have been been rehearsing for. They hope to do better than in 2009, when it took until October to deliver the first vaccines against the pandemic of H1N1 swine flu.
“The virus was identified in March,” notes flu expert Dr. Arnold Monto of the University of Michigan. Six long months ticked by with the virus spreading and no vaccine against it.
The U.S. government was battered by criticism from confused Americans who tried hard to get flu vaccine but couldn’t, and then gave up trying just about the time that vaccines started being produced and delivered in quantity.
Vaccine makers ended up throwing away about 70 million doses. “We can do it faster,” Monto said.
Two seasonal flu vaccines that use new technology approved within the past six months should help speed up the process. That same techonology can be used to make other vaccines, including one to protect against H7N9. And Dr. Robin Robinson of the Biomedical Advanced Research and Development Authority (BARDA), part of the Health and Human Services Department, says H7N9 is giving his department the chance for what he hopes will be a dry run.
“I think we are in a much better place than we were before the pandemic of 2009,” Robinson told NBC News. “We have some ongoing initiatives that are starting to provide real results.”
Most flu vaccines are made using technology that dates back to the 1940s. Doctors isolate the virus from a patient, combine it with another virus used to make the a “seed” for the vaccine, grow it in specially fertilized chicken eggs, strain it out and purify it – a process that takes months and that is fraught with dangers, not the least of which is contamination of the eggs.
Newer technology dumps the eggs. One new vaccine is grown in insect cells, and another is grown in cells taken from a single cocker spaniel’s kidney decades ago. That speeds things up a bit. And now scientists can make vaccine based on the genetic sequence, because they can make artificial genes in the lab.
So they can go straight from a genetic sequence published online to starting to make a vaccine. This method, called recombinant technology, shaves a few weeks off the process. Last summer, when a new strain of swine flu called H3N2v infected about 300 people and killed one, mostly via state fairs, drug maker Novartis and experts at the J. Craig Venter Institute in California made a seed virus for the vaccine in a week, Robinson says.
“Now with the H7N9 outbreak in China, the nucleotide (genetic) sequence was available Saturday, March 30,” Robinson said. Scientists at Novartis, with the federal government and the Venter Institute synthesized the necessary genes by the following Tuesday. By Wednesday, they had inserted the artificial gene sequences into dog cells and were growing new virus.
“Now we are characterizing that … virus to see if we have the right seed strains,” Robinson said. If they are, they’ll be tested and prepared to make a vaccine.
“We have been able to shave weeks off the method,” Robinson said.
When samples of the actual virus are released later this week, vaccine makers using old-fashioned methods will go to work on those, Robinson added.
“We have talked to all the manufacturers that make egg- based, cell-based and recombinant-based vaccines to ask what their manufacturing capabilities are,” Robinson said. HHS will know by the end of this week how much vaccine the companies can make and when they could have it ready, he says.
In any pandemic, the goal is to vaccinate every American. What's not clear is how many doses would be needed for protection and whether manufacturers could create enough in time.
The United States has invested heavily in vaccine technology since about 2004, when it became clear that H5N1 bird flu was a threat. So far, H5N1 has been an expensive nuisance, forcing the culling of hundreds of millions of birds, and killing 60 percent of the 600 or so human victims who have been infected.
But it could mutate into a form that passes easily from human to human. So could H7N9. Or another type of flu could emerge. Seasonal flu vaccines provide no protection at all against these new strains.
Some people have criticized the U.S. government’s reliance on commercial flu vaccines. It’s spent $147 million in five years to help companies that were struggling to develop new vaccine technology.
Seven companies make flu vaccines for the U.S. market, and the CDC and HHS are heavily invested in encouraging people to get vaccinated each year, not only to protect themselves from flu, but to keep a market incentive for companies to make flu vaccine.
But Monto says it’s the only way. “If the companies were not involved in producing a vaccine and taking risks each year, we wouldn’t have vaccines,” he says. And seasonal flu is nothing to sneeze at -- killing upwards of 40,000 people in a bad year.
Robinson says these preparedness efforts have been spared so far from budget cuts hitting other areas of government.
“We plan for these kinds of things to happen,” he said. “So far we are OK in developing the actual vaccine candidate. Where we get into trouble and will have to ask Congress for more money is if we have to have a large vaccine campaign like we had in 2009.”