None of the women involved in the trial were forced to pull out as a result of adverse side-affects. The most serious adverse side-affect reported was local discomfort at the injection site.

For starters, it could cause harm. All vaccines carry the risk of injury or death. During trials, nine individuals developed arthritis after receiving the vaccine versus three for the placebo, out of approximately 21,000 individuals in that trial. Nine kids with arthritis after receiving the vaccine might not seem like a big deal in the grand scheme of things. After all, arthritis is better than cancer, right? That depends.

Given the fact that cervical cancer is relatively rare, highly preventable and most often successfully treated early on, maybe the risk of arthritis -- a painful and often debilitating disease -- isn't a worthwhile trade-off.

And maybe we won't know the true incidence of harmful effects until the vaccine is given to millions, rather than thousands, of children and young adults.

Moreover, the whole concept of a placebo was turned on its head during the trials, preventing any valid comparison between those who were given a placebo and those who received the vaccine.

In order to learn the truth about an unknown, honest science dictates that we have to compare it to a known. When most people think about a vaccine placebo, they are probably thinking about saline. But that's not what was used during trials.

The "placebo" in this case was an aluminium-containing shot. The vaccine itself also contains aluminium.

Aluminium hydroxide is what's known as an adjuvant — it stimulates immune response. Studies in both animals and humans have found that aluminium adjuvants can cause death of brain cells. Similar studies have also shown that aluminium adjuvants in vaccines can cross the blood-brain barrier, as well as cause injection-site inflammation leading to chronic joint and muscle pain and fatigue.

Aluminium adjuvants have never been subjected to clinical trials for safety. Read that again: Although the metal has been used in vaccines for decades, it has never been rigorously studied for long-term safety.

So perhaps the 1 case of lupus and 2 cases of arthritis out of 9,701 participants who received the "placebo" were not just statistical anomalies. Maybe it was the aluminium. Perhaps that would also explain the 1 case of juvenile arthritis, 2 cases of rheumatoid arthritis, 5 cases of arthritis and 1 case of reactive arthritis in 11,813 Gardasil recipients. We'll never know. (Some of the trial participants did, in fact, receive straight saline but there's no way to tell from the data released which cases are which.)

More importantly, a reactive placebo artificially decreases the appearance of danger of an experimental vaccine in a clinical trial because the drug company only has to prove that adverse events weren't statistically significant in the vaccine group versus the placebo group. So using aluminium-containing placebos falsely inflates the adverse-event data of the "placebo" group, making the vaccine look relatively safe by comparison.

Gardasil contains 225 mcg of aluminium. Neither Merck nor the U.S. FDA would answer my questions as to how much aluminium was used in the placebo. (Sanofi Pasteur MSD is marketing the vaccine in Europe and is a joint venture of French company Sanofi Pasteur and U.S. pharmaceutical company Merck.)

Clinical trial investigators dismissed most of the 102 serious adverse events including 17 deaths that occurred in the clinical trials as unrelated to the study. But given the reactivity profile of aluminium, can we really say that for sure?

Nearly 90 percent of all Gardasil recipients and 85 percent of those who received the "placebo" reported one or more adverse events within 15 days of vaccination. Pain and swelling at the site of injection affected approximately 83 percent of Gardasil recipients and 73 percent of those who received the aluminium placebo. About 60 percent of those who received either the vaccine or the placebo had systemic adverse events including headache, fever, nausea, dizziness, vomiting, diarrhoea and myalgia. Those who received the vaccine reported even more serious adverse events such as gastroenteritis, appendicitis, pelvic inflammatory disease, asthma, bronchospasm and arthritis.