Fighting HIV Without Traditional Vaccines

Why can't scientists just develop a universal vaccine against HIV and the swine flu? Is it because the biopharm industry wants to make money each year off of a new vaccine?

The answer to the second question is a definite "no", but the answer to the first question is far more complicated....

The problem is that HIV, and in fact many viruses, do not play fair. Viruses, although not technically "alive", evolve over time. One way that viruses evolve is by changing the protein structure of their outer protein coat. This protein coat is responsible for the majority of the properties of a virus - for example what species and types of cell in infects. In viruses, the evolutionary rate of change is higher than that of living organisms, for several reasons, including the fact that viruses lack DNA repair mechanisms. This means that they accumulate mutations faster, and often these mutations change the outer structure of the virus. Since vaccines are prepared using purified outer proteins of a virus, you can see how as viruses evolve they make previous vaccines ineffective. Such is often the case in the flu vaccine, where the yearly vaccines are prepared from the previous year's flu viruses. Vaccines for HIV has so far met limited success, and epidemiologists balk at the idea of putting a vaccine on the market which would make people think that they are safe. Furthermore, HIV belongs to a class of viruses called the retroviruses, an especially nasty sub-set of viruses that accumulate mutations faster than most.

Vaccines, when introduced into the body, cause the immune system to target specific cells and proteins for destruction. This is called the specific immune response, and one of the ways that it works is to produce antibodies against the invading virus. Unfortunately, we all do not generate the same antibodies, meaning that a vaccine in one person might not have the same result as in another. Coupled with the high mutation rates of viruses, this causes real problems in developing a population-wide vaccine for highly mutable viruses.

But what if we could bypass the whole antibody-generation step and instead introduce virus-specific antibodies into the body. These antibodies could be designed to target a specific type of virus, and would actively recruit the cells of our immune system to destroy the virus before it caused significant damage. This type of procedure has just been reported for HIV-type infections in primates, and the initial results suggest that it might hold promise. And not only for HIV, but also for viruses such as H1H1 (swine flu) and H5N1 (avian flu). Both of these are now in the human population, and the development of an effective vaccine against them both is not soon forthcoming, so adding a new technique to our anti-viral arsenal is well advised.


For more information - see Jon Cohen's article in ScienceNow
"Designer Antibodies Derail Monkey AIDS Virus"

The Swine Flu "Pandemic"

Welcome to the new world of medical sensationalism. The recent "outbreak" of the H1N1 virus, aka "swine flu" has provided some of the major news networks with the ultimate story. Scare the public and increase ratings, it worked with terrorism, and now it appears to be working with the swine flu pandemic. From pictures of Dr. Gupta, CNN's medical authority, wearing a worried look and a face mask, to Vice-President Biden's gaff about why all Americans should cease flying immediately, the American people are being fed misinformation on H1N1 at an alarming rate. And they are scared. Airline stocks are plummeting, people are avoiding pork, and sales of surgical masks are increasing exponentially. In Vermont, the National Gaurd is escorting deliveries of anti-viral medicines to hospitals. And, of course, the religious crazies are out predicting the "end of days".

Every day we are reminded of the swine flu death toll. For example, on today's CNN page (May 3, 2009), there is a headline article stating that "Confirmed Cases of H1N1 Virus Approach 900". It is important to realize that 900 deaths, while seemingly significant, really is not. Cancer kills over 440,000 Americans per year, or about 1200 a day. Over 9000 Americans, 24 each day, die from contaminants in the food that we eat. In fact, 900 deaths worldwide represents about 0.00013% of the world's population. This is a nasty little virus, with some interesting genetics (see tomorrow's post!), but it is not yet a global killer. And due to some rather quick work by scientists, we already know more about this virus than most.

So why the panic? Mostly because people do not understand the jargon of the people who study infectious diseases. Yes, there is a pandemic... but it is important to recognize what the word pandemic really means. An epidemic is an outbreak of a disease in a localized population, while a pandemic simply means that the epidemic has moved into neighboring populations. In today's world, most epidemics, and all flu outbreaks, go pandemic quickly. A pandemic is not Armageddon, it is simply a widespread outbreak of a disease.

Some people will say that the news networks are just keeping people informed. But the reality is that this bout of swine flu is going to fade rather quickly as summer progresses, and with this fading will be the attention of the American people. But, unfortunately, the virus will be back, and it could return with a vengeance. But due to the actions of the news networks, we are now in the "boy who cried wolf" syndrome. When this virus, or one of its close relatives returns, most people will ignore the advice to get a vaccine, thinking that this is just another "news story", and not a real threat. After all, they have already survived the "threats" from avian and swine flu, how bad can it get? The answer is, very bad indeed. Viruses are patient little objects, and a few seasons of low activity often preclude a true outbreak in a population. H1N1 may not be bad this year, but if it mutates over the summer, we could have problems next year if we don't prepare now by planning ahead and funding the agencies that work to protect us from infectious outbreaks.

For more, quality, information, stop watching the infomercials known as the nightly news, and check out real sources such as the CDC. Take prudent precautions, the same as you would take during any high-disease season. Wash your hands frequently, especially when you have been in public spaces, and see your doctor if you develop flu-like symptoms. But lets stop the panic and sensationalism, and instead use our brains to think.