In a study just released by Dartmouth Medical School researchers, not all cervical cancer vaccines work the same or offer the same benefits. Comparing Cervarix to Gardasil, both cervical cancer vaccines designed to protect against the human papillomavirus, HPV, found Cervarix to be longer-lasting and provides protection against multiple strains of virus linked to the development of cancer. Gardasil does not offer these same benefits. Gardasil does offer protection against HPV strains associated with genital warts, which Cervarix does not offer.

Cervarix offers high level protection against HPV types 16 and 18 for up to 4.5 years, and cross-protects against HPV-45 and 31, two other strains of the virus associated with cancer. According to the researchers, the long-term response appears to be due to the use of the adjuvant ASO4 with Cervarix rather than the adjuvant alum that is used in the Gardasil vaccine. This is significant because a vaccine that uses adjuvant alum needs to be administered around the time of exposure, so timing is important to vaccine protection. However, a vaccine that uses adjuvant ASO4 can be administered at any time to offer protection. Gardasil uses adjuvant alum, Cervarix uses adjuvant ASO4. When these cervical cancer vaccines are approved for use, I wonder if women are going to faced with the decision of what type of protection they want and in what form. Or will they find a way to combine the benefits of both into one vaccine? Important information for women to keep in mind when the vaccine becomes available, because there are critical differences between the two vaccines mentioned in this post.