Tag: vaccine (page 1 of 2)

the effects of bad science

Vaccination

A new epidemic of measles has broken out in Wales. Vaccination rates fell after a paper linking the vaccine to autism was published in the 1998. The paper was later proven to be fraudulent. NPR reports:

More than 1,200 people have come down with measles so far this year, following nearly 2,000 cases in 2012. Many of the cases have been in Wales.

Childhood vaccination rates plummeted in Great Britain after a 1998 paper by Dr. Andrew Wakefield claimed that the vaccine for measles, mumps and rubella had caused autism in a dozen children. That study has since been proven , but it fueled fears about vaccine safety in Great Britain and the United States.

“This is the legacy of the Wakefield scare,” Dr. David Elliman, spokesman for the Royal College of Pediatrics and Child Health, told The Associated Press.

Most of the measles cases have been in children and teenagers between the ages of 10 and 18, according to British health officials. In that age group, vaccination rates dropped below 50 percent in some parts of England after the Wakefield paper was published.

AIDS vaccine fails

Scanning electron micrograph of HIV-1 budding (in green) from cultured lymphocyte

The past two weeks brought plenty of interesting science news, including the failure of a potential AIDS vaccine. From Popular Science:

The study, called HVTN-505, was begun in 2009, over the years enrolling over 2,500 volunteers. The vaccination process doesn’t actually involve any live or even deactivated HIV; instead, it starts with one that includes genetic material that’s simply modeled after the virus, to prime the immune system. Then comes the real vaccine, involving recombinant DNA (meaning, DNA from various sources) based on adenovirus type 5, a common cold virus that in this case has been disabled so it doesn’t actually cause a cold. Attached to those adenoviruses are artificial versions of HIV antigens. Antigens–the term is short for antibody generator–trigger an immune response, and these artificial antigens were designed to attack the three major HIV subtypes.

This technique had shown some mild success before; in a study in Thailand in 2009, it showed a 31 percent reduction in the HIV infection rate, which sounds good to me, but is apparently not enough to really do more than encourage further research. Unfortunately, that was as much success as this strategy ever saw.

hollow viruses

Popular Science highlights this paper from PLOS Pathogens. The research discusses creating hollowed out versions of viral capsids. These capsids would stimulate the immune system to produce antibodies without any potential for infection since the virus’ genetic material has been removed.

Call it hollow-hearted. Researchers have built a mimic of the outer capsule of the foot-and-mouth disease virus. Inside, where the virus’ genetic material normally lives, is empty.

Such synthetic virus-like particles could go into a foot-and-mouth vaccine that’s cheaper to make because it doesn’t require the tight biosecurity that a factory that makes vaccines from live viruses needs, its creators say. The researchers have also built the virus mimic in such a way that it can stay out of a refrigerator for longer than current foot-and-mouth vaccines, so it could ship more easily around the world.

In the future, the same techniques could apply to vaccines to the polio virus, which belongs to a large group of viruses related to hoof-and-mouth, Andrew Macadam, a polio researcher at the U.K. National Institute for Biological Standards and Control, told the BBC. Polio vaccines are now made with either weakened or killed polio viruses. (The weakened type still carries a small risk of reverting to its original form and causing paralysis. That vaccine is no longer used in the U.S., but some other countries give it out because it doesn’t require a highly trained medical professional to administer.)

The researchers hope it will lead to cheaper and less risky vaccines.

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