Thursday, September 24, 2009

Combining Two Failed HIV Vaccines Makes a New Failed Vaccine

The BBC has this article whose headline reads "HIV vaccine 'reduces infection'". Fifty-one people out of 8,197 people vaccinated contracted HIV, while 74 people out of 8,198 people who were not vaccinated and used as controls contracted HIV. The difference is not statistically significant. In biology, two = one for most biological results because biological systems are so complex, and there were a lot more variables than could be controlled for in this vaccine trial. Look at it this way, 0.622 per cent contracted HIV from the treated group versus 0.902 in the untreated group. Both results can be rounded up to 1 per cent. I'd like to see a similar vaccine trial on gays or IV drug users. Those are high risk groups for HIV infection and if the vaccine offered any protection, the data would likely show it. My guess is that the combinatorial vaccine would fail that test.

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I to am uneasy about headlines about marginal results for drugs that still need a decade of funding. The private profit making nature of drugs and therapies is a big distorter of the ideal scientic process.

Lots of snake oil + government or insurance money = profits.

Pete
 
Pete,

I agree with your concerns. However, governments usually make vaccines because the expense in development, production, and use is not profitable for most pharmaceutical firms. Most vaccines prevent the disease and are cost-effective and economical. Antibiotics are the same against microbes, but both agents are generally not profitable for drug makers. Hence, we see little antibiotic or vaccine development privately. Influenza is an exception since the vaccine is only effective against certain strains and the virus evolves rapidly, so influenza vaccine production is quite profitable annually because each year's vaccine is useless the following year.

Regarding your concerns though, see this URL: http://www.huffingtonpost.com/dr-mark-hyman/why-cholesterol-may-not-b_b_290687.html about cardiovascular disease and statins. You have to treat 50 people with expensive statins to see any benefits (decrease in death rate). You only have to treat one person with an infection with an antibiotic to see a benefit.

"In those at high risk for heart disease about 50 people would need to be treated for 5 years to reduce one cardiovascular event. Just to put that in perspective: If a drug works, it has a very low NTT (number needed to treat). For example, if you have a urine infection and take an antibiotic, you will get near a 100% benefit. The number needed to treat is "1". So if you have an NTT of 50 like statins do for preventing heart disease in 75% of the people who take them, it is basically a crap shoot."

Not much bang for all that buck so it would seem.

John
 
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