Despite recent news report to the contrary, the US Centers for Disease Control and Prevention (CDC) provides Science Insider efforts to make a vaccine against the virus causing the swine flu outbreak have not encountered unexpected delays.
Confusion about the chronology of the vaccine from a report by the World Health Organisation (WHO) yesterday, who told a meeting organized by a scientific working group which studied closely production problems. The Advisory Working Group concluded that manufacturers would not be able to begin "large scale production" of a vaccine against the new H1N1 virus until mid-July. The report did not describe these as delays, but many media accounts did, noting that Marie-Paule Kieny, WHO, the director of the WHO's initiative for vaccine research, earlier predicted that production could begin two months earlier and suggested that a vaccine could be ready as soon as September.
Tom Skinner, spokesman for the CDC, assured science Insider that everything is on track. "We hope we can have a loan late autumn vaccine; However, we know that the manufacturing process is complicated, and we must be ready in case we encounter glitches with vaccine production, "said Skinner. The time, of course, depends on the specific steps in the manufacturing process, and the CDC and the WHO working group seem to have different estimates on some key points.
the vaccine process begins with viral isolate being converted into "seed stock." CDC has already five isolates sent to seven laboratories to make the starting material. a key property of the seed bank is that it is a weakened or attenuated version of the original virus, making it a safer production process and reduces the risk of an accidental release.
Skinner said CDC expects the seed stock in hand next week. According to the WHO report, it will then take 1 to 2 weeks of testing animals to ensure that the seed stock is attenuated. But Skinner said CDC simultaneously perform these tests on animals and send the seed stock for some manufacturers who biosafety level laboratories 3-plus (BSL-3 and more), which are specially designed to work with dangerous pathogens. "Those who have BSL-3 laboratories as well, and some will begin immediately," said Skinner, who points out that the United States, it all depends on the government to decide to get the vaccine, which does has not happened yet.
the WHO report says that manufacturers must then typically 1 to 2 months "to isolate rapid growing strains for maximum efficiency." Skinner said no. "They to do some more work on it to get in the condition they need for the vaccine, and I thought that takes a few weeks, so that the middle of June to the end of June, they could start to produce a lot of drivers, "he said. These pilot batches are used in small clinical trials to make sure the vaccine is safe and triggers the appropriate immune responses, a process that takes about 8 weeks Skinner said.
But Skinner points out that manufacturers are not normally put the production of commercial batches of vaccines waiting until they have the results of the batch of pilot tests. "They will not wait until everything is done to start producing the vaccine than the rest of us might need in the fall and winter," said Skinner. "These two processes are parallel. "
As to exactly when this vaccine can be ready, Skinner says this is a question for manufacturers. A spokesman for GlaxoSmithKline, a major manufacturer of vaccine against influenza, said, "We expect the first doses of H1N1 vaccine would be available 4 to 6 months after receipt of the seed strain, pending regulatory approval." this means that the vaccine would be available in mid-October to mid-December and that is assuming there are no unforeseen manufacturing problems or regulatory issues surface. wHO Kieny May 1 estimated that it would take only 4 to 6 months to produce a vaccine from the time of virus isolation, which means September 1 availability.
is CDC concerned that the vaccine may not be ready in time? "It is safe to say that we are considering several scenarios in mind when a vaccine could be available, "Skinner said.
Even if the uS government decides to buy the vaccine, Skinner acknowledges that the country can not eventually use the product if the spread of the new H1N1 virus does not justify. "We will be looking very closely what happens during the summer here in the United States, but especially what happens in the southern hemisphere regarding the new H1N1, to have this information to decide what, if anything, we're going to do regarding a vaccination campaign later this fall and winter, "said Skinner." But if we think we might need a vaccine, we must now to ensure that we have one, and what we do. "
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