Acambis hopes to build a flu vaccine that lasts

first_imgAug 25, 2005 (CIDRAP News) – The British biotechnology firm Acambis recently announced its launching of a quest for the Holy Grail of influenza prevention: a vaccine that would protect people from the virus for many years and perhaps even stave off future pandemic strains.With current technology, flu vaccines have to be retooled every year in a time-consuming effort to cope with minor mutations that enable the flu virus to avoid quick detection by the immune system. But a vaccine based on parts of the virus that stay the same, instead of those that often change, could eliminate the need to bring out a new model every year.Acambis announced early this month that it was collaborating with Belgium’s Flanders Interuniversity Institute for Biotechnology (known as VIB) to replace the annual flu vaccine with a perennial one.”The aim of the research collaboration would be to generate a ‘universal’ vaccine candidate that would protect against both A and B strains of influenza and, more importantly, would not require annual changes to the formulation,” the company said in its Aug 4 announcement.The company hopes that such a vaccine could also protect people from a pandemic flu virus, which can arise from a major change, or “antigenic shift,” in viral components. With disease experts warning that the H5N1 avian flu virus could turn into a pandemic strain any day, that prospect is doubly attractive. However, availability of such a vaccine is, at best, years away—too far in the future to help combat any near-term pandemic.The frequent minor changes in flu viruses involve two of the virus’s surface proteins, hemagglutinin and neuraminidase, represented by the H and N in names like “H5N1.” Hemagglutinin and neuraminidase enable flu viruses to enter host cells and then exit them after replicating. Current vaccines target these highly mutable proteins, making it necessary to adjust the vaccines each year to match the circulating strains.Acambis’s vaccine effort focuses on a far less shifty viral protein, called M2. “A major component of the new [vaccine] candidates,” the company said, “will be M2e, the extracellular domain of the ion channel protein M2, which is specific to influenza A. Being highly conserved, M2e is intended to elicit protective immune responses against all strains of influenza A. M2e is incorporated in a unique carrier system that forms highly immunogenic virus-like particles.”Ashley Birkett, Acambis’s director of viral immunology in Cambridge, Mass., said the company is working on a separate technology for type B influenza. If the type A and B vaccines both prove effective, combining the two into one shot “would give us a truly universal vaccine,” he told CIDRAP News.The A type vaccine would potentially protect people against pandemic flu, since previous known pandemic strains were type A and future ones are expected to follow suit, Birkett said.”The advantage of this approach is that the manufacturing relative to the vaccine would be much easier,” he said. “It would be the same vaccine year after year.”Since the vaccine wouldn’t have to be changed each year, manufacturing could be continuous, instead of occurring each spring and summer after health officials pick the flu strains they think will prevail the following winter. With year-round manufacturing, people could be immunized any time of year, not just in the fall or winter, and vaccine could be stockpiled, Birkett said.Conventional production of flu vaccine involves growing whole copies of a weakened virus in chicken eggs (though several companies are working on growing flu viruses in cell culture). Acambis’s experimental vaccine is manufactured with a “recombinant bacterial fermentation technology,” in which bacteria are used to make selected viral proteins, rather than whole virus. “The bacteria can make single proteins for us,” Birkett said.With this technique, the production time for a batch of vaccine is “a matter of weeks,” as compared with about 6 months for egg-based vaccine, he said. “But the main difference is you’re going to be making the virus year-round. It really comes down to the fact that we don’t have to change the product,” he added.Acambis said its initial vaccine candidate is “in pre-clinical development” and has been tested successfully in animals. Two recent journal articles describe successful tests of various versions of the vaccine in mice.The reports, published in Virus Research and Virology, say that M2e generates only a weak immune response during flu infection and when used in a conventional vaccine. But when it is linked to an appropriate carrier, such as hepatitis B virus core (HBc) particles, it induces a strong antibody response. When various versions of the M2e-HBc combination were used with an adjuvant (a chemical that stimulates the immune system), they fully protected mice from a potentially lethal flu infection, the reports say.Work on the vaccine has already been going on for several years. Acambis said it acquired the vaccine from Apovia, a US biotechnology firm, earlier this year. Apovia started developing the vaccine in 2000, after licensing the technology from VIB, where Walter Fiers led the research on which the vaccine is based.Birkett said he couldn’t predict when the firm might launch clinical trials or how long it might take to bring the vaccine to licensing, but indications are it will be a lengthy effort.Theoretically, a perennial flu vaccine is a great concept, said Gregory Poland, MD, a vaccine expert at the Mayo Clinic in Rochester, Minn.”One of the real problems we have is that each year, the vaccine is an educated guess,” Poland told CIDRAP News, referring to the problem of predicting which flu strains will predominate in a given season. “The other problem is getting large numbers of people to get a vaccine every year.”A single vaccine that would reliably fend off the shifty virus for years would eliminate both of those difficulties. “A flu vaccine that could be given once, twice, or periodically would be a grand slam,” said Poland, who is a professor of medicine in infectious diseases at the Mayo College of Medicine and directs the Mayo Vaccine Research Group and Program in Translational Immunovirology.But Poland was cautious in assessing the likelihood of success.”We need a proof of principle at this point,” he said. “There are a number of entities trying to develop a similar vaccine. I do think it’s theoretically possible. From an immunologic point of view, the key will be choosing the right antigen [viral protein] and knowing that the antigen is displayed early in the infection, so that an immune response can be generated early enough to abort the infection. My concern is if you find antigens that are displayed late in the infection, you may generate an immune response too late to do much good.”Birkett acknowledged that the experimental vaccine targets the virus later in its life cycle than conventional vaccines do. “But if you want a universal vaccine, you have to target a component that develops later in the life cycle,” he said.”It’s a totally new vaccine approach,” he said. “We’re confident, we’re hopeful, but until we do the [clinical] studies, we won’t know for sure [if the vaccine will work]. If it does work, it’ll be the Holy Grail. It could meet the need for influenza [protection] year after year.”Acambis is not the only organization pursuing a universal flu vaccine. The National Institute of Allergy and Infectious Diseases (NIAID) is supporting efforts by several other researchers on the same problem.Andrew Pekosz of Washington University in St. Louis and David Milich of the Vaccine Research Institute in San Diego are working on a vaccine that, like Acambis’s, targets the M2 protein of the influenza A virus, according to an article on the NIAID’s influenza Web site.Because relatively few copies of the M2 protein are present on the outer coat of the virus, an M2-based vaccine made from a normal flu strain generates only a weak immune response, the article notes. Milich is addressing this problem by developing a “bulked up” M2 vaccine that contains 240 copies of the protein, which stimulates the production of more antibodies.Other researchers working on similar vaccines include Walter Gerhard at the Wistar Institute in Philadelphia and Gary Van Nest at the biotechnology company Dynavax, according to the NIAID. Gerhard’s vaccine targets the M2 protein, while Van Nest is using another viral protein, called NP.Poland predicts it will take years to bring a universal flu vaccine to market, if it can be done at all. “I wouldn’t hold my breath that we’re going to have a vaccine like this in the next couple of years,” he said. “I think proof of principle you could get in a couple of years. For licensure of a vaccine like that, the typical cycle is going to be somewhere in the 7- to 10-year horizon.” But he added that it might be possible to speed up the process, especially if the vaccine would be effective against a pandemic virus.See also:Aug 5 Flanders Interuniversity Institute for Biotechnology releasePubMed abstracts with links to full text of reports on M2e influenza vaccine:A ‘universal’ human influenza A vaccine (Virus Research 2004)Universal influenza A vaccine: optimization of M2-based constructs (Virology 2005)last_img read more

Virat Kohli is positive despite losing to Chennai Super Kings

first_imgChennai: It was a start that Royal Challengers Bangalore (RCB) skipper Virat Kohli would like to forget as his team was thrashed by seven wickets by defending champions Chennai Super Kings (CSK) in the season opening game of the 12th edition of the Indian Premier League (IPL) here.But trying to remain positive despite the result on Saturday, Kohli said that it was good to get a loss like this out of the way early in the tournament. Having scored just 70 runs after losing the toss and batting first, Kohli’s men saw Chennai chase down the target in the 18th over of the innings.He revealed that the idea was to take the game as deep down as possible after a poor start with the bat.“No one wants to start like this, but it’s good to get a game like this out of the way – this early in the tournament. We spoke of trying to be in the game, taking it to the 18th over was nice to see.”While one would think it was a poor reading of the wicket that saw RCB play three frontline pacers in Umesh Yadav, Mohammed Siraj and Navdeep Saini, but Kohli backed the decision and said that the wicket looked much better than it played.“The batting wasn’t good, it wasn’t easy to bat on, looked much better surface though. I thought 140-150 would have been an ideal score, especially with dew expected later on. A scrappy start to the league, but I don’t think either team had control over it, the pitch was under the covers for 4 days, but we should have batted better, 110-120 would have been a fighting score,” he said.Also Read: SPORTS NEWSlast_img read more

Hardik Pandya Joins Hands With Nat Geo

first_imgNew Delhi: Indian all-rounder Hardik Pandya has joined hands with National Geographic’s ‘Choose The Planet’ initiative and has called upon people to reduce single-use plastic and make India free of the menace.On the occasion of 150th birth anniversary of Mahatma Gandhi, Pandya tweeted: “When it comes to the planet, we are all on one team. Planet or Plastic? I #ChooseThePlanet.”He also nominated his teammates – Rohit Sharma, Krunal Pandya and KL Rahul to take the pledge. (IANS) Also Read: Pakistan Cricketer Abdul Razzaq ‘I can Make Hardik Pandya One of The Best All-Rounders’Also Watch: Durga Puja 2019: Puja Preparations at Naba Bikas Sangha in Guwahlast_img read more

Region 10 RDC calls for burnt-out Post Office to be rehabilitated

first_imgWeeks after the Wismar Post Office had been set on fire, officials have renewed calls for Government to release funds in a timely manner to enable rehabilitation of the building, and ultimately return to senior citizens efficient delivery of their old age pensions.The Post Office was torched in the wee hours of August 2 when bandits broke into the building in an attempt to cart off cash designated to pay pensions.? However, the safe withstood their attempts at broaching it, and the perpetrators allegedly set the building on fire in retaliation.The issue of rehabilitating the Post Office was discussed at the statutory meeting of the RDC on Thursday.The current situation has created difficulties for many Wismar residents, especially senior citizens, who depend on services provided by the Post Office. Wismar Pensioners are forced to collect their old age pensions at the Mackenzie Post Office, and they complain that this it is time consuming and costly for those whoRegion Chairman Renis Morianare not in the best of health.In seeking a solution, Regional Chairman Renis Morian told members of the Council that he has since written several Government officials on the issue, including President David Granger.Morian pointed out that the Mackenzie Post Office is presently plagued by overcrowding and other issues, and cannot cope with the influx of pensioners at any given time.He further noted that he has since met with officials of the Guyana Post Office Corporation, and he pointed out that the entity needs the support of the Council.On the day of the incident, the region’s engineer was tasked with completing a bill of quantities for reconstruction of the Post Office building.This was completed, and the repairs are expected to cost approximately $14.3 million. Morian related that he visited the Mackenzie Post Office on Monday and observed the overcrowding, coupled with the heat and lack of proper waiting facilities.The Regional Chairman added that the Post Office needs the support of the council, since it serves people of their constituencies. The council is hoping for positive response from Government officials. As well, the Chairman hopes a solution would be arrived at very shortly.“”I sent a letter to the Minister of Finance, along with the bill of quantities, highlighting the plight of the residents… I’m asking the system to deliver $14.3 or $14.5 million. Find the money…the letters are out. I’m giving this whole matter another week, and if I don’t get some positive response, then I gotta up the ante”.The Regional Chairman stressed that the temporary fix to facilitate the pensioners at the Mackenzie Post Office is not working, owing to the numbers.In addition, Councillor Charles Sampson noted that the Post Office should have been treated as an emergency, and work should have already commenced, since it serves a significant amount of citizens.“Even if the Post Office Corporation doesn’t have funds to effect immediate repairs, immediate repairs should have started… Why are we taking so long? As far as I see, that’s an emergency…I hope that by the next pension day…we do something about the Wismar Post Office. Most of the pensioners live over at Wismar”, he noted.Meanwhile, Councillor Gordon Callendar noted that a contractor is expected to visit the site of the Wismar Post Office on Friday to assess the situation.The Mackenzie Post Office is currently accommodating staff of the Wismar Post Office to aid in the better delivery of service at the facility. However, this is not without challenges, the Regional Chairman has pointed out.He said the Council is committed to finding an urgent solution to deal with the plight of Wismar residents.last_img read more