Archive for the ‘Vaccines and Anti-virals’ Category
Federal panel issues H1N1 vaccine guidelines
CNN Senior Medical Producer
ATLANTA, Georgia (CNN) — A federal advisory committee issued sweeping guidelines Wednesday for a vaccination campaign against the pandemic swine flu strain, identifying more than half the U.S. population as targets for the first round of vaccinations.
The advisory panel’s guidelines don’t trigger the start of vaccinations but are usually accepted by the government.
The priority groups include pregnant women; health care and emergency services personnel; children, adolescents and young adults up to age 24; household and caregiver contacts of children younger than six months; and healthy adults with certain medical conditions.
The guidelines were approved in a near-unanimous vote by the 15-member Advisory Committee on Immunization Practices. One person dissented on whether to include people ages 19 to 24 among those targeted.
The vote does not trigger a decision to vaccinate against the disease, also called H1N1, but the federal government typically follows the committee’s recommendations.
The recommendations could prove especially important if the pandemic strain, which emerged this spring, spreads widely before sufficient quantities of vaccine can be produced to protect everyone. The recommendations are intended to ensure that members of the most vulnerable groups get priority.
Earlier Wednesday, federal officials said they are on track to initiate a mass vaccination campaign by October, although many details remain to be worked out. Clinical trials to assess vaccine safety and efficacy are just getting under way at a handful of centers across the country.
Dr. William Schaffner, a flu researcher at Vanderbilt University, which is running one of the clinical trials, played down safety concerns that have been raised because safety data are limited.
“There is no alternative” to approving the new vaccine based on the limited data, he said. Fortunately, he added, “the novel H1N1 vaccine is created exactly the same way our seasonal vaccine is created, year in and year out.”
Dr. Wellington Sun of the Food and Drug Administration said data from those trials would probably be available in September.
However, Dr. Robin Robinson, director of the Biomedical Advanced Research and Development Authority at the Department of Health and Human Services, said that that even if federal regulators determine that the vaccine is safe and effective, it would take an additional four to six weeks before it could be packaged and available to the public.
About half of Americans — 159 million — fall into one of the five main target groups, including 102 million people aged 6 to 18.
Robinson had predicted earlier that 120 million vaccine doses would most likely be available within a month after the campaign starts.
Dr. Anthony Fiore of the Centers for Disease Control and Prevention, who led the group’s deliberations, said it made sense to target such a large group because it appears that vaccine supplies will be sufficient.
Part of that estimate is based on experience with seasonal flu vaccine; Fiore said that, typically, only 20 percent to 50 percent of people in targeted groups seek out seasonal flu vaccine.
Even if two doses of the swine flu vaccine are required to confer protection — something that will be determined in clinical trials — suppliers would probably be able to ramp up production quickly enough to meet demand, Fiore said.
But the advisory committee approved a backup plan in case supplies are more limited. In such a case, the priority groups would be pregnant women, health care and emergency services workers with direct patient contact, household contacts of children younger than 6 months, children age 6 months to 4 years and children younger than 19 with chronic medical conditions — a total of 42 million people.
The panel also recommended that, once sufficient supplies exist to meet the needs of all targeted groups, the vaccine should be offered to healthy adults ages 25 to 64. Once those needs are met, vaccinations would be recommended for people older than 65.
The targeted groups differ starkly from the recommendations for seasonal flu vaccine campaigns, which include people 65 and older in the highest-risk group.
The difference is based largely on data showing vastly higher infection rates among younger people; the rate of laboratory-confirmed cases in Americans 65 and older is just 0.06 per 100,000, compared with 2.6 per 100,000 for the group with the highest infection rates, children 5 to 11.
Studies have found that many older Americans carry at least some antibody protection against the new virus, probably because it is similar to flu viruses that circulated widely in the 1920s through the early 1950s.
Some of the most alarming complications have been seen in pregnant women. A paper published Wednesday in the journal Lancet reported that pregnant women infected with H1N1 are more likely to be hospitalized and even die. Of the 45 H1N1 deaths reported to the CDC between April 15 and June 16, six (13 percent) were among pregnant women.
Obesity has not been determined to be a risk factor, Fiore said.
The H1N1 flu vaccination campaign would run concurrent with the usual seasonal flu campaign, which the committee recommended get under way as soon as possible.
Vanderbilt’s Schaffner said patients should get the seasonal vaccine before distribution centers are swamped with demand for the pandemic vaccine.
But he also warned that the new vaccine might be of limited use. “The virus and the vaccine are in a race; the virus may win,” he said.
If the pandemic strain starts spreading fast between now and October, he said, hospitals and medical personnel will be pushed to the limit.
“It’s like thinking about a hurricane. You batten down the hatches. You do everything you can. But when the hurricane arrives, damage will occur. This one is going to be a doozy.”
Australia to begin first human test of swine flu vaccine
(CNN) — The first human trials of a swine flu vaccine are expected to start in Australia Wednesday, as the World Health Organization confirmed that more than 700 people had died from the virus worldwide.
A scientist examines samples from suspected swine flu patients at a WHO laboratory in Melbourne, Australia.
Melbourne-based company CSL Ltd. plans to test a vaccine for the H1N1 virus, also known as swine flu, on 240 volunteers, a company representative said.The test will be conducted on healthy adults between the ages of 18-64. Participants will receive two shots three weeks apart and will undergo blood tests to determine if they are generating an appropriate immune response to the virus, the company said.
“We appreciate that new influenza strains like the ‘swine flu’ can surprise us with properties that mean they might require higher dosing and two injections rather than one to provoke the desired level of immune response in humans,” said Dr. Russell Basser, global director of clinical development for CSL.
The World Health Organization revealed Tuesday that more than 700 people had died after contracting the virus, 260 more than the latest death toll, released July 6. The jump in the death toll is due simply to the two-week gap in reporting cases, a WHO spokeswoman explained.
The H1N1 virus has spread around the world with unprecedented speed, according to the WHO. Past influenza viruses have needed more than six months to spread as widely as the current H1N1 virus has spread in less than six weeks, it said.
Because there are so many cases emerging so quickly, the WHO changed its reporting guidelines last week. It decided to stop giving a tally of cases and focus instead on identifying unusual patterns. The counting of all cases is no longer essential because it is exhausting countries’ resources, the organization said Monday, commenting on the policy change.
While the virus is spreading quickly, the WHO offered some reassurance to those concerned about the disease. It said the virus has so far been characterized by mild symptoms in most patients, who usually recover — even without medical treatment — within a week of developing symptoms.
Meanwhile, a group of British children and teachers quarantined for almost one week in a Beijing hotel because of swine flu fears have been allowed to leave their hotel.
A spokesman from Britain’s Foreign Office could not confirm the number of children and teachers released from quarantine, but said they were among a group of 111 that was sequestered in a Beijing hotel six days ago.
The students and teachers came from various schools in Britain and were all traveling to China together as members of the same British school association, the Specialist Schools and Academies Trust.
Twelve children were hospitalized and diagnosed with the H1N1 virus, commonly known as swine flu. One child is in the hospital awaiting test results to confirm the virus, the Foreign Office said.
The group released from quarantine Tuesday will now be moved to a different hotel, the Foreign Office said. The second group is due to be released from quarantine Wednesday, the Foreign Office said.
WHO declared H1N1 a global pandemic on June 11. More than 120 countries have reported cases of human infection since the virus was first identified in Mexico in April. There are more than 98,000 documented cases worldwide.
How Fast Could a Swine Flu Vaccine Be Produced?
A doctor at the Centers for Disease Control examines specimens of the 1918 pandemic influenza virus, part of an effort to develop new vaccines and treatments for future pandemic influenza viruses
With the first reported death from the 2009 H1N1 flu, or swine flu, in the U.S., the Federal Government and flu-vaccine manufacturers are preparing for the possibility that a new vaccine will be necessary to control the outbreak. Should the call for vaccine production come from health officials, both traditional and newer, faster vaccine-making methods could be employed.
Dr. Richard Besser, acting director of the Centers for Disease Control and Prevention (CDC), said the agency has begun cultivating the seed stock of virus needed for a swine flu vaccine. (The current seasonal flu vaccine would not be effective against the swine flu.) “We’re moving forward aggressively so that if a decision is made that we need to rev up production to make that vaccine, we would be ready to do so,” he said.
But even if the CDC’s seed stock of virus were to be released to vaccine makers today, it would take the companies anywhere from four to six months before the first inoculation could be ready for public use. That’s because flu-vaccine production — whether for swine or seasonal flu — is time-consuming and laborious, requiring vaccine makers to grow millions of copies of the flu virus in chicken eggs, then purify those bugs into a ready-to-inject formula safe for patients. “We are moving things around to accommodate this and getting our raw materials ready and having our scientists ready. We are on alert, waiting on the CDC. We’re in daily contact with them,” says Donna Cary, spokeswoman for Sanofi Pasteur, which currently makes 50 million doses of the seasonal flu vaccine used in the U.S. each year.
But if and when the CDC gives the go-ahead, companies such as Sanofi will have to do an about-face, scrapping their current vaccine projects to switch to swine flu. Sanofi and other vaccine makers received the seed stock for the upcoming flu season last January and are now in the midst of culturing and purifying that virus for this fall’s flu season.
History teaches us, however, that it won’t be easy. The last time the U.S. recommended nationwide vaccination against a suspected swine flu was in 1976, with less than successful results, to say the least. Under orders from President Gerald Ford, a vaccine was rushed into production and administered to 45 million Americans, at a cost of $135 million. But within weeks, people started developing Guillain-Barré syndrome, a paralyzing immune-system disorder that can result from the vaccine. Some experts estimated the risk of Guillain-Barré as being seven times higher in those who were immunized vs. those who were not. After the immunization program was terminated nine months after it began, government officials paid $90 million in damages to patients who were injured by the vaccine. The widely feared swine flu epidemic never emerged.
Much has changed since then. Genetic advances have given researchers entirely new ways of developing vaccines. For example, instead of using the entire virus or bacterium to activate the human immune system, new strategies rely on genetic snippets from infectious bugs, which can trigger immunity without the risk of infection.
At the biotech company Novavax, researchers are testing the use of virus-like particles (VLP), instead of the virus itself, to stimulate a flu immune response. Using this method, a vaccine for the 2009 H1N1 virus could be in production in 10 to 12 weeks, rather than the usual four to six months. “We have made vaccines against multiple flu strains and tested them in humans and gotten relevant and robust immune responses, which checks off the major boxes that the technology works against flu,” says Rahul Singhvi, president and CEO of Novavax.
Novavax’s strategy involves isolating three proteins from the virus that flag the human immune system, which then churns out neutralizing antibodies against the proteins. These antibodies are robust enough to fight off the actual virus should an immunized person become infected. This is the same way the recently developed vaccine against human papilloma virus, Gardasil, works. “It provides the look and feel of the flu virus but does not have the genetic materials to cause disease,” Singhvi says.
A VLP vaccine may also prove easier to develop since all it requires is an accurate genetic sequence of three critical virus genes. That could especially help with swine flu, since researchers found back in the 1970s that the virus doesn’t grow well in chicken eggs; that could slash the yield and slow production of a potential new vaccine. “As long as we get the genetic sequence of some viral proteins, it doesn’t matter where the virus came from — human, swine or bird,” says Singhvi. So far, Novavax’s shot is still in the testing phase, but its VLP-based vaccines against seasonal and bird flu are providing good results. The company stands ready to try its strategy against swine flu if needed. “The CDC is aware of what we are doing, and we have offered to help both the Department of Health and Human Services and the CDC,” says Singhvi.
Other companies are taking an entirely novel approach and hoping to pick off influenza viruses in the nasal passages before they get deeper into the body and infect other cells. At NanoBio Corporation, a biotech company in Michigan, scientists are perfecting a topical nasal spray that would destroy any single-celled particles, like viruses, bacteria or fungi, on contact, while leaving our multicelled tissues intact. (Blood cells would be fair game for the destructive emulsion, however, so the solution could not be injected into the body.) In animal studies, says Dr. James Baker, the company’s chairman of the board, the spray protected 90% of mice from a lethal dose of influenza. The company is also testing a combination of the traditional flu vaccine with the emulsion, which, says Baker, provides a 50-times-greater immune response than the vaccine alone, even if using only one-sixth the usual vaccine dose. This technique is still too experimental to be helpful against the current swine flu outbreak, however.
So far, 10 states have confirmed cases of swine flu, including a death in Texas, but all 50 have already requested their portion of the Strategic National Stockpile (SNS) of antiviral medications, according to the CDC. (The SNS, maintained jointly by the Department of Homeland Security and the Department of Health and Human Services, is the nation’s emergency medicine chest, containing critical drugs and medical equipment to be used in a public-health emergency.) Although the stockpiled antiviral drugs can treat existing cases of flu, a vaccine is the only way to protect people who are uninfected and halt further spread of the virus.
The CDC, the only agency that possesses the virus needed to make a vaccine, says it is still “looking very intently” at a swine flu vaccine, but it has not yet given the green light to scale up production. In the event that it does, either in response to the current outbreak or down the road when the next pig-to-people flu causes massive illness, they may have better ways than they did in ’76 to battle the bug.
