Pattern of multiple human papillomavirus infection and type competition: An analysis in healthy Chinese women aged 18-45 years

To assess the pattern of multiple human papillomavirus infection to predict the type replacement postvaccination. A total of 7372 women aged 18-45y from a phase III trial of an Escherichia coli-produced HPV-16/18 vaccine were analyzed at enrollment visit before vaccination. Hierarchical multilevel logistic regression was used to evaluate HPV vaccine type and nonvaccine-type interactions with age as a covariate. Binary logistic regression was construed to compare multiple infections with single infections to explore the impact of multiple-type infections on the risk of cervical disease. Multiple HPV infections were observed in 25.2% of HPV-positive women and multiple infections were higher than expected by chance. Statistically significant negative associations were observed between HPV16 and 52, HPV18 and HPV51/52/58, HPV31 and HPV39/51/52/53/54/58, HPV33 and HPV52/58, HPV58 and HPV52, HPV6 and HPV 39/51/52/53/54/56/58. Multiple HPV infections increased the risk of CIN2+ and HSIL+, with the ORs of 2.27(95%CI: 1.41, 3.64) and 2.26 (95%CI: 1.29, 3.95) for multiple oncogenic HPV infection separately. However, no significant evidence for the type-type interactions on risk of CIN2+ or HSIL+. There is possibility of type replacement between several pairs of vaccine and nonvaccine HPV type. Multiple HPV infection increased the risk of cervical disease, but coinfection HPV types seem to follow independent disease processes. Continued post-vaccination surveillance for HPV 51/52/58 types and HPV 39/51 types separately was essential after the first and second generation of HPV vaccination implementation in China.

Vaccine-associated hypersensitivity

Vaccine-associated hypersensitivity reactions are not infrequent; however, serious acute-onset, presumably IgE-mediated or IgG and complement-mediated anaphylactic or serious delayed-onset T cell-mediated systemic reactions are considered extremely rare. Hypersensitivity can occur because of either the active vaccine component (antigen) or one of the other components. Postvaccination acute-onset hypersensitivity reactions include self-limited localized adverse events and, rarely, systemic reactions ranging from urticaria/angioedema to full-blown anaphylaxis with multisystem involvement. Risk of anaphylaxis after all vaccines is estimated to be 1.31 (95% CI, 0.90-1.84) per million vaccine doses, respectively. Serious hypersensitivity reactions after influenza vaccines are particularly important because of the large number of persons vaccinated annually. Influenza vaccines are unique in requiring annual changes in the vaccines' antigenic composition to match the predicted circulating influenza strains. Recently, novel influenza vaccine types were introduced in the United States (recombinant vaccines, some with higher antigen content and a new adjuvanted vaccine). Providers should be aware of changing recommendations on the basis of recent published evidence for persons with a history of egg allergy to receive annual influenza vaccination. Further research is needed to elucidate the pathophysiology and risk factors for reported vaccine-associated adverse events. Further research is also needed to determine whether repeated annual inactivated influenza vaccination, the number of vaccine antigens administered at the same time, and the current timing of routine infant vaccinations are optimal for overall population well-being.