vaccines
revere | September 26, 2007If you are in the elderly population (over 65 years of age) you are in the crosshairs of CDC's influenza vaccination program. The reasons seem clear -- at first, anyway. Risk of influenza-related death (as measured by a specific statistical technique to estimate excess mortality during influenza seasons) increases dramatically after 65 tears of age. If you are over 80, for example, your risks of being in the excess death category is more than ten times those in the age 65 - 69 age group. Three-quaters of the flu related deaths in a normal flu season are in the 65 plus group and more than half…
revere | September 20, 2007For whatever reason, TB control is back on the front burner. TB remains a worldwide scourge and has always had a dedicated cadre of public health professionals battling it. Now they are getting some new ammunition and reinforcements. The Bill and Melinda Gates Foundation is weighing in with a substantial $280 million five year program, most of which goes to vaccine development. An effective TB vaccine is the Holy Grail of TB control. We know much more about the immune system than in the past, so maybe soon we'll see the breakthrough everyone in the field has been hoping for. Until preventive…
revere | September 18, 200710,000 ducks in Guangdong Province in the south of China have died of bird flu and 100,000 more culled in an attempt to stop the spread of the disease. Massive bird flu outbreaks are not exactly a novelty these days but the Chinese incident is noteworthy because it is now reported the ducks were in vaccinated flocks:
According to Guangdong Animal Epidemic Prevention Center director Yu Yedong, the 9,800 ducks that died at Sixian village had been vaccinated. But he added the first vaccination could only be 65 percent effective, while a second shot would have made it 90 percent.
He believed the…
revere | August 19, 2007The big pandemic flu vaccine news of the moment has to be The Lancet report that vaccine maker GlaxoSmithKline has been able to get excellent antibody production against H5N1 with a new adjuvanted preparation that contains remarkably little viral antigen. This is important because the currently the only FDA approved pre-pandemic H5N1 vaccine uses more than 20 times as much (90 micrograms versus 3.8 micrograms) in an unadjuvanted preparation with much worse antibody response.
In today's Lancet, Isabel Leroux-Roels and colleagues report safety and immunogenicity data from a phase-1 dose-sparing…
revere | August 12, 2007Another press release on a vaccine breakthrough from NIH. This one allegedly predicts the mutations that will result in enhanced transmissibility. Just published as a paper in the journal Science, the focus was on mutations of the HA protein (the "H" part of H5N1) that are related to binding to human cells versus bird cells. We have discussed this pretty often here (for the science background see the posts here):
The research group compared the structural proteins on the surface of bird-adapted H5N1 influenza virus with those on the surface of the human-adapted strain that caused the 1918…
revere | August 3, 2007Stories about experimental vaccines that "work in animals" are a dime a dozen these days. That's not bad. It means there is a lot of activity on the innovative technologies front. But there is a huge distance between "works in mice" and "works in humans." So news that one of these technologies is entering human trials, even small scale Phase I trials, is rarer. Recently we posted on the proposed start of Phase I clinical trials for a "universal flu vaccine" that works across subtypes (H5N1, H1N1, H3N2, etc.) as well as across drift variations within subtypes (the genetic differences seen from…
revere | July 20, 2007The first of the putative "universal" vaccines against influenza A is entering Phase I (small scale safety and efficacy) testing. Manufactured by UK vaccine company Acambis, the vaccine is designed to protect against a wide range of influenza A viruses of many subtypes and many strains. Here's the idea. The immune system mainly "sees" viral proteins on the outside of the virus. The most visible of these is the hamagglutinin (HA) protein which gives its initial letter to the H-subtypes like H5N1 and H3N2, etc. The other visible protein is the neuraminidase (NA) protein, the initial letter of…
revere | July 17, 2007In the world of opera a diva is a prima donna, often problematic in behavior, but in the world of bird flu, DIVA stands for differentiating infected from vaccinated animals (DIVA). The bird flu DIVA relates to a problematic behavior of vaccinating poultry: after you've artificially induced them to produce antibodies against bird flu, you are faced with the trying to tell if a bird with antibodies against bird flu got it artificially or naturally. Since antibody detection is the main screening method for poultry infection with avian influenza virus most countries won't accept imports of…
revere | July 2, 2007The New Scientist has a story this week asking whether flu vaccines really protects the elderly. It's not a new question. Careful epidemiological analyses of national mortality data has seemed to show no change in mortality amongst the elderly when vaccination for seasonal influenza ramped up starting in 1980. On the other hand, careful randomized clinical trials in specific populations seemed to show substantial protection.
The problem is more technically difficult than appears at first sight. On the one hand in a clinical trial you are making individual level measurements of both exposure (…
revere | June 22, 2007This site has a Creative Commons license on it. Essentially this means anyone can copy, distribute or transmit my blog posts for whatever purpose they want -- even commercial purposes. The only restriction is that this unrestrictive license travels with the post. If you use something from us you must permit anyone else to take the same post from your site without asking permission; and to attribute it to us at Effect Measure (i.e., give us credit, ideally including a link back to this blog).
We think this is a good model for influenza viruses, too. Because without it we are headed for…
revere | June 14, 2007One of the big issues over sharing of viral isolates from Indonesia was the contention, probably well justified, that the poor nations would be last in lie for any vaccine that might be available in the event of a pandemic. While a well matched vaccine has to await the emergence of a pandemic strain, there are good reasons to think vaccines made from pre-pandemic strains would provide some cross-protection, and such vaccines are already in production, although in small quantities.
The choke point is the clearly inadequate global production capacity for influenza vaccine. Even if there were a…
revere | June 12, 2007An extremely interesting article is slated to appear in the American Journal of Epidemiology later this month. I haven't seen it yet but Nature News carried a short piece about it. It comes from a team of experts in seasonal flu patterns at NIH's Fogarty International Center (FIC).
The notion that flu epidemics start in areas of high population density and spread outwards may not hold true for the tropics, hints a study from Brazil.
In that country, new research reveals, flu starts in the less densely populated north and moves towards cities in the south. The result indicates that climate,…
revere | June 1, 2007The world's five decade influenza surveillance system can be added as more collateral damage to George W. Bush's Global War on Everybody he Doesn't Like:
Anti-US sentiment contributed to Indonesia's success in leading developing countries to push the U.N. health body into agreeing to change a 50-year-old influenza virus-sharing system, the health minister said.
Iran, Iraq, Cuba, North Korea, Bolivia and Myanmar were among the 23 countries supporting Indonesia's argument that the existing system of unconditional sample-sharing was unfair to poorer nations, because they could not afford…
revere | May 22, 2007The word "vaccine" comes from the Latin word for cow (vacca), as many people know. Infecting people with cowpox (whose medical name is now vaccinia) cross protected them against smallpox, a piece of folk knowledge exploited by Jenner in 1796, when he introduced the practice of inoculating people with cowpox as a preventative for smallpox, then one of world's most deadly scourges. Originally called vaccine inoculation it was quickly shortened to vaccination, and Pasteur later employed "vaccine" for another preventative prepared from infectious material to protect against disease. The back and…
revere | May 18, 2007WHO's Director General is talking tough, but is she talking tough to the right people? We don't know, but we can keep our eye open for results:
Addressing concerns raised by developing countries such as Indonesia, Chan said she was committed to finding ways of distributing potentially life-saving vaccines in the event of a human influenza pandemic.
"WHO recognises the concern of many developing countries and I am fully behind you. That's why we are taking a series of actions to make sure that developing countries have equitable access to affordable pandemic vaccines," she said.
Chan also…
revere | May 16, 2007"Promise them anything, but give them Arpege" was a famous perfume ad campaign of the 1960s. Indonesia is free with promises, but what it is actually handing out doesn't smell like Arpege. After promising (for at least the third time since January) to resume sharing of viral isolates, we find only three clinical specimens, not isolates, have arrived in Japan but the provision of specimens or isolates from another 12 known and confirmed cases from Indonesia is unclear.
After refusing to share H5N1 avian flu viruses with the World Health Organization since the start of the year, Indonesian…
revere | May 16, 2007The squabble about viral isolates originating within the borders of Indonesia notwithstanding, the simple fact is that if there were a pandemic there is only a fraction of the needed productive vaccine capacity necessary globally. What fraction? Good question.
The earth is home to 6 billion people, give or take a few hundred million. And a few hundred million doses is our global vaccine capacity in the event of a pandemic. The annual capacity is estimated around 300 - 400 million, possibly 500 million if pushed. That's annual production. If we had to ramp up a specific pandemic strain from…
revere | May 15, 2007Indonesia has just registered its 76th death and 95th case of bird flu, making it the country with more of each than any other nation. Not that you would know it by looking at the current WHO count of confirmed cases. That's because Indonesia hasn't sent WHO any viral isolates for confirmation since January. We've covered this too often to repeat the details (see here, here, here, here, here, here, here, here and here for some background), but the issue is now front and center in this week's World Health Assembly, the official governing body of WHO convened in Geneva:
The issue of sharing…
scientificactivist | May 11, 2007This week's New England Journal of Medicine is a virtual smorgasbord of articles on HPV (human papilloma virus) vaccination. Although HPV also causes unsightly genital warts, HPV is more or less the sole cause of cervical cancer. I've written quite a bit here about Merck's HPV vaccine, Gardasil, since a February 2007 executive order by Texas governor Rick Perry made the vaccine mandatory for sixth grade girls in the state but was subsequently overturned by the state legislature (and Perry announced just this Tuesday that he would not veto the bill, which had been passed by a veto-proof…
revere | May 10, 2007The stand-off between Indonesia and the rest of the world over sharing of viral isolates obtained within its borders continues. Indonesia has identified a problem, but in our opinion, has no standing to impose its proffered unworkable solution. Everyone tends to see this from their own particular perspective, so we'll give you ours. We aren't WHO (and have had no contact with them on this matter) and we aren't citizens of Indonesia or any other developing country. We are citizens of a rich, developed country. But we are also long time, committed public health professionals. I think we have…