A post-mortem will be performed today on Natalie Morton, the British schoolgirl who collapsed and died yesterday after receiving her first Cervarix shot. The FDA’s vaccine advisory board recently gave Cervarix the nod for use in the US, but today the FDA again put approval for GlaxoSmithKline’s vaccine against two cancer-causing strains of the human papillomavirus (HPV) on hold because it “needs more time to review the product.”
The National Health Service has taken the suspect batch of Cervarix off its shelves and suspended its HPV vaccination program for a couple of days. Although several other girls complained of feeling faint and ill and asked to go home, it’s not known whether the apparently healthy schoolgirl’s death was caused by a bad batch of the vaccine, or a very rare reaction, or was simply coincidental. Cervarix is given to all Year 8 girls (aged 12-13) in Britain’s schools unless their parents opt out of the vaccination program.
Like Gardasil, Merck’s competing HPV vaccine, Cervarix contains genetically engineered virus-like particles (VLPs) and girls are given three separate shots over several months. However, Gardasil uses a standard aluminum adjuvant to enhance immune response, whereas Cervarix contains AS04, a novel adjuvant that delivers a stronger and more sustained immune response.
Gardasil has been anecdotally associated with multiple deaths and severe adverse events, including rapid onset paralysis, although the FDA insists that the benefits outweigh the risks. A recent report found that there is no conclusive evidence linking Gardasil with any side effects other that syncope and a slightly raised risk of blood clots.
In February 2009 a batch of Gardasil was sequestered in Spain when two young girls started convulsing shortly after the vaccine was administered. The two girls were repeatedly admitted to intensive care in the following months. Spain's vaccination program resumed after an investigation ruled that Gardasil did not cause the convulsions, although it could have “triggered” them. Auto immune diseases arise in genetically predisposed individuals after being triggered by an environmental factor.
The HPV vaccine is typically given to girls as young as 9, but more often around the age of 12, before the start of sexual activity. It isn’t yet known how long the vaccine will protect against the strains of HPV it guards against, whether other strains will fill the biological niche left vacant, or what its effect will be on natural immunity against the virus. Currently, about 80 percent of the population will be infected with one or multiple strains of the virus at some point in their lives but some 95 percent of infections will be shrugged off. Persistent infections can eventually lead to cervical cancer unless caught by a routine annual Pap test. Gardasil has been shown in Merck’s testing to prevent 17-45 percent of cervical abnormalities, not 70-100 percent as is commonly reported.
Gardasil and Cervarix are intended to “kill the invader” (or at least a couple of the invaders—15 strains of HPV out of more than 100 are known to be oncogenic) rather than “strengthen the host” via a strong immune system. Immune systems can be weakened by smoking, insufficient sleep, and poor diet—a 2007 study found that less than 10 percent of American teens get the recommended number of fruits and vegetables in their daily diet. Multiple sexual partners and lack of circumcision also increase the chances of getting a persistent infection.
Although both vaccines are now given only to girls, Gardasil is hoping to widen its market reach soon as FDA approval for its use on boys is anticipated.