A persistent criticism from opponents of the Pentagon’s anthrax vaccination program is the charge that defense officials purposely put squalene in some vaccine lots to boost troops’ immune responses and increase the length of time vaccine stocks would remain effective.
The Pentagon and the vaccine’s manufacturer have repeatedly denied those charges, but opponents continue to question whether the fatlike substance may have played a role in illnesses developed by some troops who got anthrax shots during the 1991 Persian Gulf War and in the early stages of the Pentagon’s mandatory anthrax vaccine program in the late 1990s.
Although squalene occurs naturally in the human body, some scientists say injecting even small amounts can cause illness.
Now, a study is drawing attention to another anthrax vaccine additive with possible serious side effects — aluminum hydroxide, a substance routinely added to many common vaccines to spur production of antibodies, though scientists are not sure how it does that.
Defense officials acknowledge the vaccine contains aluminum hydroxide, which the Federal Drug Administration considers safe for use in vaccines in small amounts. But a study to be published in the February 2007 issue of Neuromolecular Medicine says aluminum hydroxide at levels normally found in vaccines killed neurons in the brains of mice and sparked serious side effects.
The squalene battle
Squalene, a cholesterol-building compound, is produced naturally by the body in small amounts.
A Pentagon-initiated test by Stanford Research Institute International conducted between May 1999 and September 2000 found no squalene in the anthrax vaccine.
In late 2000, the FDA announced it had found traces of squalene in five lots of anthrax vaccine. All had been sent to Dover Air Force Base, Del., where scores of pilots reported muscle aches, memory loss, headaches, severe fatigue and other symptoms after being ordered to take the shots in 1999.
Defense officials have insisted the presence of squalene in those lots was accidental.
“The level ... identified by the FDA test is so minute that it is likely the result of squalene in the oil of a fingerprint not cleaned from lab glassware,” states the Pentagon’s anthrax vaccine Web site, www.anthrax.osd.mil.
But then-base commander Col. Felix Grieder told the media as recently as 2004 that he believed his airmen were used as guinea pigs for illegal medical experiments.
A 1999 Tulane University study also found squalene antibodies in veterans of the 1991 Gulf War who had received anthrax shots.
No medical study ever has pointed to a conclusive cause of the symptoms collectively known as Gulf War illnesses. But participants in the 1999 Tulane study all had similar symptoms and the same squalene antibodies in their blood — even those who never actually deployed to the Persian Gulf.
In the study to be published in February, a collaboration by one American and four Canadian scientists, mice were injected with two doses of adjuvants, chemicals that boost immune response, at a level normally expected in vaccines, scaled down to mouse-sized proportions.
Some mice received aluminum hydroxide, some got squalene, and others received both.
“The greatest overall effects were seen in mice injected with aluminum hydroxide,” the study states. The substance killed brain neurons and led to “progressive and significant decrease in muscular strength and endurance,” loss of long-term memory and motor control, and behavioral problems.
Researchers also compared the symptoms of veterans suffering from Gulf War illnesseses and amyotrophic lateral sclerosis —Lou Gehrig’s disease — with the symptoms observed in mice given aluminum hydroxide.
In addition to spinal cord problems, the mice suffered neuron death in the same parts of the brain affected in human motor-function diseases like ALS and Parkinson’s. Several studies have shown an above-average incidence of ALS among Gulf War veterans.
“These results are consistent with a potential role for aluminum in motor neuron death in ALS,” the study says.
The researchers acknowledge that variables such as stress, multiple vaccinations and exposure to other toxins could cause or intensify negative reactions to adjuvants.
But they also say even the possibility of negative effects from aluminum hydroxide suggests that its use in anthrax vaccine and other vaccines for the military and the general public should be reconsidered and studied further.
“Whether the risk of protection from a dreaded disease outweighs the risk of toxicity is a question that demands urgent attention,” the study says.
At press time, Defense Department officials had not responded to several requests for comment on the study.