Wednesday, March 27, 2013

Gardasil Vaccination Rates are Below Expectations

In 2006 the FDA approved Gardasil, the first vaccine against the sexually transmitted human papilloma virus (HPV). HPV is responsible for most cases of cervical cancer. The hope was that most girls would be vaccinated against HPV at about age 11, before they began sexual activity.

At first, Gardasil seemed destined for widespread acceptance (see this blog, Oct. 14, 2010). But more extensive data show that the rate of vaccination has remained lower than expected. According to the most recent data from the Centers for Disease Control and Prevention (CDC), only 35% of all girls 13 to 17 years of age have received all three of the required shots. And an article in Pediatrics this month reports that the number of parent planning to have their girls vaccinated is declining, rather than increasing.

The new findings are of concern to health officials. No one knows why vaccination rates are still so low. Possibilities include the uneasiness of parents to address the issue of sexual activity in girls as young as 11; concerns about vaccine safety; the need for three shots rather than just one; the fact that Gardasil is not administered at the same time as all other childhood vaccinations; even the cost ($400-$500).

Health officials are struggling with how to encourage parents to have their pre-adolescent girls vaccinated. Ideas include providing more education about the value of the vaccine in preventing cancer; lowering the cost of the vaccine; making vaccinations more convenient by requiring only the first dose to be delivered in a health care setting (the others could be given in schools or at pharmacies). Only time will tell which if any of these strategies will work. But it’s a shame that we now have a vaccine that would prevent about 4,000 deaths per year from cervical cancer, and a lot of girls just aren’t taking advantage of it.

Saturday, March 23, 2013

Antibiotic-resistant Enterobacteriaceae

We’ve all heard about how bacterial resistance to antibiotics could cause real problems for us down the road. Most reports of antibiotic resistance have focused on a bacterium called MRSA, or methicillin-resistance Staphylococcus aureus, a highly resistant strain of bacterium that infects the skin as well as the lungs and other vital organs.

Now there’s another one, called CRE, or Carbapenem-resistant Enterobacteriaceae. Enterobacteriaceae typically reside in the gut (a very common enterobacteriaceae is E. coli). Some strains of enterobacteriaceae (like MRSA) have become resistant to most known antibiotics, including carbapenem, which is generally an antibiotic of last resort.

According to the Centers for Disease Control, CRE infections are still fairly rare. They tend to occur primarily in patients who are hospitalized for other conditions and who are on ventilators, have bladder catheters, or are connected to IV (intravenous) catheters. However, when CRE infections do occur they are exceedingly dangerous because they are so hard to treat – according to one estimate they contribute to death in perhaps half of all patients who are infected.

The fact that CRE is currently limited to certain types of hospitalized patients is mildly reassuring, for now. But because enterobacteriaceae are fairly common in humans, health care workers are concerned that resistant strains like CRE could make the jump to the wider human community. Prevention strategies are being worked out as we speak.

Tuesday, March 19, 2013

Golden Rice Makes a Comeback

Remember “golden rice”, the genetically modified (GM) rice containing a gene that encodes for beta-carotene, the precursor to vitamin A? The developers of golden rice had hoped that the rice would solve the problem of vitamin A deficiency in many regions of the world. Just 50 grams of the newer strains of cooked golden rice provide 60% of the minimum daily requirement for Vitamin A.

Opposition to GM foods is much stronger outside the U.S., where golden rice was most likely to be planted and consumed (the U.S. is not a major rice consumer). Golden rice soon came under attack by international environmentalists and anti-GM foods activists around the world, who saw the rice as a potential threat to the environment and a risk to human health. Their opposition to golden rice (indeed, to any GM foods, regardless of potential benefit) caused the company holding the patent on golden rice to abandon its plans to commercialize it, and it was never planted commercially. However, that may change soon. According to an article in The Guardian, golden rice may be approved for planting in the Philippines as early as next year.

The resurgence of interest in golden rice more than a decade after its development coincides with a decline in opposition to GM crops generally. After all, we now have 30 years of experience with GM crops, and quite frankly, the kinds of disasters predicted by the opponents of GM foods have simply not materialized. With continued vigilance to ensure that GM crops are safe, GM crops are likely to continue to gain in acceptance.

Thursday, March 14, 2013

Stockpiling Smallpox Vaccine

Smallpox was eradicated completely in 1980. The only known stocks of the virus that causes smallpox are in carefully guarded laboratories in the U.S. and Russia. Nevertheless, the U.S. government is spending nearly $500 million for about two million doses of smallpox vaccine, according to a recent article in the New York Times.

Does this make sense? Well, yes and no. No one knows for sure whether there are unreported stocks of the virus somewhere, and if there are, whether they might fall into the wrong hands. Apparently the U.S. government thinks that it would be prudent to have a stock of smallpox vaccine on hand, just in case the smallpox virus is used someday in a bioterrorism attack.

Only time will tell whether stockpiling smallpox vaccine will prove to be a $500 million waste of money or a lifesaver. But while you’re considering whether you think it’s a good idea, consider this; if there is an outbreak of smallpox some day, who will be able to get the vaccine? Two million doses wouldn’t cover even a quarter of the population of New York City alone. How much of this vaccine should we be stockpiling?

Saturday, March 9, 2013

Should Artificially Sweetened Milk be Labeled as Milk?

What is the “standard of identity” for milk? This may sound like a silly question, but condensed milk, evaporated milk, and milk all have very specific specifications, as defined by the FDA. The FDA keeps close watch on such things to prevent food manufacturers from misrepresenting their products.

The FDA revealed last week that it is considering a petition from the dairy industry for a rule change that would allow milk to be sweetened with “any safe and suitable sweetener”, such as aspartame. Furthermore, the dairy industry wants the sweetened milk to be called just milk, without having to reveal on the front of the container that it contains sweeteners. The industry is worried about flagging sales of plain old boring milk, and they’ve come up with a marketing solution - make it taste sweeter!

To convince the FDA that this would be a good thing, the dairy industry makes the argument that making milk taste sweeter will allow it to compete more effectively with sugary drinks. The industry’s logic is that if milk tasted sweeter, more kids might choose milk it over sugary drinks. And that, they say, would help combat obesity.

Huh? Getting kids used to sweeter-tasting milk (and thus to sweet-tasting drinks) will somehow reduce their preference for sugary foods and drinks and combat obesity? You’ve got to be kidding. The industry’s petition to the FDA has prompted an angry response from parents and consumer groups. The FDA is inviting public comments on the issue through May 21, 2013, after which it will make its decision. If you have an opinion, you can register it on the FDA’s website.

Wednesday, March 6, 2013

The Embryoscope for Monitoring IVF Embryos

Fertility clinics have a new tool for monitoring the early development of fertilized eggs into blastocysts/embryos, before a decision has to be made regarding which embryos(s) to implant in the woman. It’s called the Embryoscope Time-lapse embryo monitoring System, or just the Embryoscope for short. The Embryoscope is an incubation chamber with a built-in time-lapse microscopy and data recording system that can incubate and monitor up to 72 embryos at a time. Because the embryos do not need to be removed repeatedly from the incubation chamber to be examined, the risk of damaging the developing embryo is reduced. In addition, the operator can review the entire dynamic sequence of cell divisions of the embryo rather than just selected snapshots in time. (For a time-lapse view of embryonic development, see the NBC news report on the Embryoscope) Time-lapse microscopy allows the operator to assess the precise timing of each cell division and whether or not the cell divisions are synchronous. (Do the first two cells divide into four at the same time?) And because the data are stored digitally, the operator need not be physically present at precisely 12 hours, for example, to be able to assess embryonic development at the 12-hour stage.

The Embryoscope should markedly increase efficiency in the fertility clinic. It should also help health professionals decide which embryos are the best candidates for implantation. It is not known how many fertility clinics are already using the Embryoscope, but I expect the number to increase.

Friday, March 1, 2013

Auvi-Q; An Alternative to the EpiPen

Persons with potentially life-threatening allergic reactions to specific allergens (such as bee stings or certain foods) are told to carry an epinephrine auto-injector with them at all times.  A typical epinephrine auto-injector (such as an EpiPen) is a device about 5 ½ inches in length by one inch in diameter containing a single dose of injectable epinephrine.  When an allergic reaction occurs, the user is supposed to inject the epinephrine into his/her thigh as soon as possible.  I carried an EpiPen myself for a time, after I suffered a severe allergic reaction to multiple stings by ground-dwelling yellow jacket wasps.  But as time went by I stopped carrying it because it just didn’t seem necessary, and because carrying it every day was inconvenient.  Fortunately, I’ve never had another severe allergic reaction like that first one.  But what if I did?

Now there’s an alternative, called Auvi-Q.  Auvi-Q is still just a single dose of injectable epinephrine.  But Auvi-Q is shaped entirely differently; it’s about the length and width of a credit card and the width of a smart-phone.  The manufacturer hopes that it will appeal to the younger generation used to carrying credit/debit cards and phones.  More importantly, once the cover is removed Auvi-Q talks the user through the entire process of injection with a soothing human voice. (To hear the instructions, view the video on the Auvi-Q website.)  The verbal instructions may be helpful to some users and caregivers, since it may be years before the device is needed and one could forget how to use the device in that time.

The maker of Auvi-Q hopes that younger persons will find the device “cool”, and so perhaps they’ll be more willing to carry it than the EpiPen.  (The manufacturer of the EpiPen takes issue with an Auvi-Q marketing claim that 2/3 of EpiPen users don’t actually carry their EpiPen with them.)  Time will tell whether Auvi-Q is different enough to find a place in the competitive epinephrine auto-injector market.