Toward Better Vaccines

A QUANTUM OF SCIENCE

Making vaccines both optimally effective and optimally safe may be an easier task in the near future

Vaccines have an overwhelming track record when it comes to preventing illness, and thanks in part to conservative rules put in place by the federal agencies regulating them vaccines have also been extremely safe. Still, there’s an unadvertised trade-off in that compromise: vaccines would be even more effective than they are today if they could be made with heat-inactivated pathogens rather than highly purified microbial proteins generated in non-toxic bacteria, but that elevates the risk of possible immune reactions and side effects in those who take the vaccine.

To help improve the effectiveness of vaccines even when not using the heat-inactivated pathogens, scientists have long used compounds known as adjuvants to "boost" the body’s immune response. In essence, adjuvants are sensitizers that tell the body to be ready for an invader; when given as part of a vaccination, adjuvants significantly increase the vaccine’s protective effects both in duration and potency. But the only adjuvant ever approved for use in humans, aluminum hydroxide (or alum), is far from the most effective compound for the job. To date the FDA has been extremely reluctant to approve other, more powerful adjuvants for use with vaccines because of concerns about toxicity and possible side-effects.

Now scientists at Oregon State University have developed an adjuvant based on lecithin, a common food product, that shows six-fold greater immune response when administered as part of a vaccine as compared to alum-based treatments. Lecithin is part of a category of food products termed "generally recognized as safe" by the FDA, meaning that it is non-toxic in almost any dosage. This could mean a fast track to approval and, very possibly, vaccines that would be more effective, for longer periods of time, with smaller doses and fewer injections.

For more information:

New adjuvant could hold future of vaccine development

Adjuvant (Wikipedia article)

Strong antibody responses induced by protein antigens conjugated onto the surface of lecithin-based nanoparticles (Sloat et al)


© AQOS / P. Smalley (2009)
Reproduction with attribution is appreciation

Quantum: Get Stung and Get Paid

A QUANTUM OF SCIENCE

Dr. Duffy wants to give you malaria.

Well, sort of.

Researchers at the Seattle Biomedical Research Institute have developed a weakened version of the malaria bug (Plasmodium falciparum) by deleting from its genome the genetic instructions that allow it to invade the liver and to reproduce. Now SBRI has been approved to conduct human trials using this "neutered" malaria, testing various drugs and vaccines for their effectiveness at blocking the parasite.

And volunteers will get paid somewhere between $2000 and $4000 for their trouble.


For more information:

Seattle Times article "You can get paid to catch malaria"

SBRI press release on the approval to conduct human trials with malaria vaccine

© A Quantum of Science / P. Smalley
Reproduction with attribution is appreciation

Canadian scientists sequence H1N1 genome

A QUANTUM OF SCIENCE

Now we know the complete blueprint for H1N1; now what?

Today it was announced that scientists in Canada have fully sequenced the entire genome of the H1N1 influenza virus. While it's not the first viral genome to be fully sequenced, it is a landmark achievement and all the more so for having been completed in one week of around-the-clock work by scientists at Canada's National Microbiology Laboratory in Winnipeg. This is, as the saying goes, kind of a big deal.

These findings shed some intriguing light on the outbreak of H1N1 but raises even more questions, as most scientific discoveries do. For example, researchers found virtually no difference between the Mexican strains and those occurring in the US or Canada. Why, then, have so many more cases in Mexico proven fatal? The answers may not lie in the genes themselves, but rather in differences of health infrastructure and health policy. Benefits of this breakthrough include faster analysis of future strains, a better understanding of how and why H1N1 mutations or reassortments occur, and a better H1N1 vaccine - with this last being of crucial importance as major pharmaceutical companies begin the laborious process of choosing which sequences to use for their vaccines. With an improved understanding of the variations in the H1N1 genome, conserved sequences can be selected for use vaccines, resulting in a stronger, more robust protection against future infection.

Perhaps it is a little cynical, but one might consider that the timing of this announcement seems a little too convenient considering that today is the second day of the 62nd World Health Assembly, the annual meeting of the World Health Organization whose handling of the H1N1 outbreak has been criticized by many science and health professionals. Then again, maybe it is simply a case of serendipity; regardless, it is good news and that's worth remembering.

Plus, if you want to apply for the position of Viral Genome Curator at a company in Bethesda, MD, you now have one more fully-sequenced genome to add to the list.

For more information:
http://www.canada.com/Health/Canadian+completes+sequencing+virus/1569084/story.html

© A Quantum of Science / Peter Smalley (2009)
Reproduction with attribution is appreciation