A study, published in the Canadian Medical Association Journal, found the HPV adverse reaction in young women was five to 20 times higher than that identified in comparable school-based vaccination programs. However, the overall rates of anaphylaxis were low with no associated serious lasting effects.

In a 2007 study of 114,000 women in a 2007 vaccination program, a team of Australian researchers found 12 women suspected of anaphylaxis and confirmed eight of the cases. Symtoms included difficulty breathing, nausea and rashes.

The estimated rate of anaphylaxis following HPV vaccination was 2.6 per 100,000 doses administered compared with a rate 0.1 per 100 000 doses administered in a 2003 school-based meningococcal C vaccination program.