 Phase III trials have been conducted, including over 18,000 women from 14 countries in Pacific Asia, Europe, Latin America and North America.As of 2009 the manufacturer was conducting a trial to compare the immunogenicity and safety of Cervarix with Gardasil.Subsequent studies showed Cervarix generated higher antibody levels than Gardasil, the other commercially available HPV vaccine, upon testing seven months later, with twice the level for HPV type 16 and six times for HPV type 18.