Tag Archives: Vaccines

What’s in the Needle? Part 3 – Chimpanzee Virus plus a mysterious ‘adjuvant’

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Ebola vaccine testing to begin on humans[T]he race to discover an effective yet lucrative Ebola vaccine commenced in earnest about 10 years ago. Most of the research was funded fully or in part by such auspicious entities like BARDA (Biomedical Advanced Research and Development Authority) wing of DARPA (Defense Advances Research Projects Agency), the NIH (National Institutes of Health), USAMRIID (United States Army Medical Research Institute of Infectious Diseases), or NIAID (National Institutes of Allergy and Infectious Diseases). However, private money has also found its way into laboratories across the globe, and major pharmaceutical companies like Merck have led the way.

In 2007, Merck spun off a biopharmaceutical company called Okairos for its ‘clinical-stage’ vaccines. One of the most prominent of these vaccine candidates includes a recombinant vector based on chimpanzee adenoviruses. A vector is simply a molecular truck that delivers a payload into a living system. Adenoviruses can infect humans and primates (the literature will say ‘non-human primates’, but since I believe in Creation, I consider primates and human entirely different species with no common ancestry).

Originally, numerous researchers explored the human adenovirus (HAdV) as possible vectors, but many of us already have been exposed at some time previously, which means we already carry antibodies against HAdV—in fact, it is often cultured from the throats of sick children. Our natural immunity to HAdV meant it could not be used as a vector, but non-human versions could. Hence, about ten years ago, research began using various serotypes of chimpanzee adenovirus (ChAdV, sometimes written CAdV). One of the leading candidates for an Ebola vaccine includes the number 3 serotype, CAdV-3. Okairos, the spinoff from Merck, has found a way to remove the dangerous genes from the DNA genome of the adenovirus and insert an Ebola Glycoprotein (EVD-GP) instead. This allows the viral vector to express the Ebola GP on its outer membrane, which makes it look just like an Ebola virus particle. Continue reading

H3N2 Influenza outbreak among vaccinated sailors

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Graphic depicting how influenza strains are named (Wikimedia Commons) Click to enlarge.

[T]his week’s MMWR (Morbidity and Mortality Weekly Report) from the CDC included a puzzling report concerning a US Naval minesweeper. In February of this year, 25 sailors from the 102 member crew aboard the USS Ardent, an Avenger class minesweeper, began to complain of fever, chills, and cough. Doctors conducted nasal swab PCR tests and diagnosed influenza, 20 of which were influenza A, and of those 20, 18 were H3N2. Here’s the other shoe: All but one of these men had been vaccinated against influenza A. Sequencing revealed that the strain infecting most of the men had a 99% similarity to A/Texas/50/2012, but 7 of the cases showed marked mutations with 5 amino acid substitutions in the HA1 protein.

So, what happened? Why did these men, nearly all of whom had been vaccinated about 3 months prior to the outbreak, become infected with influenza A? The report seems to imply that patient zero may have been a sailor who lived in San Diego, where the minesweeper was docked, who had developed vague symptoms in January. This sailor suffered from pyelonephritis (a kidney infection), so it had been assumed that his symptoms were somehow connected to his kidney ailment. In fact, a CT scan was performed of his lungs on the assumption that he had a pulmonary embolism! This CT scan showed nothing abnormal. The sailor in question had a roommate, who also served on the Ardent, so even though patient zero remained on shore due to his illness, the roommate reported for duty according to rotation, and it’s assumed that the disease was spread in common areas or through surface contamination (hand rails, etc.).

The sub was decontaminated thoroughly, we’re told, and all the sailors recovered nicely after a round of antivirals. The source of the vaccination failure is a mystery that may never be solved.

To read the entire MMWR report, go here.

What’s in the Needle #2: Rabies and Ebola Combined

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[Y]ou might wonder whether or not I’ve added rabies just to put a ‘scare’ in my readers, but the truth is that the DoD, the NIH, NIAID, and Thomas Jefferson University have teamed up to produce a genuine vaccine candidate built on the rabies vaccine.

In a way, it makes sense. In Africa, many animals contract both rabies and Ebola and can spread both diseases to human through a bite. And until recently, very few with deep pockets felt inclined to put their investment dollars into a vaccine that might be used or not (vaccines do have a shelf life). Let’s face it, most pharmaceutical companies prefer to make a profit, and their investors expect one, so it makes selling the idea much easier if you can guarantee sales year after year. Rabies vaccines must be repeated every 1-2 years (at least in our dog they do), so it’s probable that wildlife managers and zoos would line up to buy something that protected against rabies and filoviruses.

So, how is a rabies vaccine going to work against Ebola—a very different type of virus. Put simply, it has to be genetically modified, which makes this a recombinant vaccine.  Dr. Joseph Blaney who works for the NIAID (National Institute of Allergy and Infectious Diseases) is listed as a lead author on some of the research that first appeared in publication around August, 2011 (I say ‘around’ because this is the earliest version I could find online, but I’m not precluding and earlier publication). Another researcher on the project is Dr. Peter Jahrling, one of the giants in filovirus research—and a name familiar to anyone who has read ‘The Hot Zone’. These two along with many other diligent researchers have found what appears to be a ‘bivalent’ (confers immunity for two serotypes) vaccine with income potential, which means it might actually be produced.

To create their little chimera, the researchers took what is called an attenuated rabies virus. Continue reading

What’s in the needle? A look at Ebola vaccine candidate VSV-EBOV

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Transmission Electron Microscope image of Vesicular Stomatitis Virus (source: Wikipedia)

[B]eginning about fifteen years ago, several teams of researchers in various nations began in earnest to pursue a viable vaccine against Ebola and Marburg filoviruses. In about 2013, two candidates reached monkey experiments (what are commonly called ‘non-human primate’ trials) and reported rousing success. Today, we’ll discuss one of those candidates, VSV-EBOV.

Yesterday, news percolated throughout the MSM that VSV-EBOV would be the first filovirus vaccine to be tried on humans in the United States (currently, a human trial is being conducted in West Africa on health worker volunteers, but more on that tomorrow). According to an article from CBC.ca:

The first human clinical trials of a Canadian-developed Ebola vaccine, VSV-EBOV, begin in Maryland today to assess the vaccine’s safety and determine the appropriate dosage to fight the virus that has killed more than 4,000 people, largely in West Africa, Health Minister Rona Ambrose has announced.

“We are able to share some very promising and hopeful news in the fight against Ebola,” Ambrose said from Calgary.

[…]The vaccine, which was developed by scientists at the Public Health Agency of Canada’s National Microbiology Laboratory in Winnipeg, will be tested on 20 healthy volunteers at the Walter Reed Army Institute of Research in Silver Spring, Md.[i]

So, what’s in the vaccine? To begin with, VSV-EBOV is a type of recombinant vector vaccine. This technology is relatively new, and simply means that the genome of the ‘vector’ has been altered. Vectors are like molecular trucks, and in this case the ‘truck’ is VSV. Continue reading