Human papillomavirus and cervical cancer risk perception and vaccine acceptability among adolescent girls and young women in Durban, South Africa.

BACKGROUND: The relationship between HIV and cervical cancer is well established. Interventions that focus on creating human papillomavirus (HPV) vaccine and cervical cancer prevention messaging for adolescents, caregivers and educators will increase uptake of HPV vaccinations, HPV testing and cervical cancer screening for high-risk adolescent girls and young women (AGYW). In order to effectively develop appropriate interventions, it is important to examine AGYW's perceptions regarding their personal risk of acquiring HPV, as well as vaccine acceptability. OBJECTIVES: To measure the level of perceived personal risk of acquiring HPV and developing cervical cancer; examine the sociodemographic and behavioural factors associated with perceived risk; and assess HPV vaccine acceptability. METHODS: AGYW aged 16 - 24 years participating in the AYAZAZI study in Durban, South Africa (SA), were invited to participate in the AYA-HPV Prevention Project (AHPP), and were administered a questionnaire that assessed HPV, cervical cancer and vaccine awareness and knowledge, self-perceived HPV and cervical cancer risk, HPV vaccine uptake and acceptability, and participation in cervical cancer screening. The questionnaire measured self-perceived risk of acquiring HPV and developing cervical cancer for the respondent and other young women, as well as vaccine acceptability. Data from the main AYAZAZI study (12-month) visit were linked to AHPP substudy data. Descriptive statistics were used to analyse sociodemographic variables at the 12-month time point. Self-perceived HIV, HPV and cervical cancer risk was measured using an ordinal scale. Chi-square analyses were used to examine differences in sociodemographic and behavioural factors according to self-perceived risk of HPV and cervical cancer. RESULTS: Only a small portion of participants (14.3%) had heard of HPV. Overall, 43.0% (n=49) perceived themselves as at low HPV risk. There were significant differences in self-perceived risk of cervical cancer by age group, income and pregnancy status. The highest proportion of AGYW who perceived themselves as at high risk of cervical cancer reported being sexually active (p=0.002). Although many participants reported not knowing about HPV prior to the study, after learning about it during the study, most said that they would be willing to receive the vaccine (97.5%). CONCLUSIONS: Most young women in SA do not have access to the national HPV vaccine programme, as only girls in grade 4 in some public schools qualify. Almost all participants indicated that if the vaccine was free and recommended by a healthcare professional, they would accept it. Availability of the HPV vaccine and timely treatment of HPV infections are key issues to address in efforts to decrease cervical cancer worldwide.

Cutting edge: myeloid complement C3 enhances the humoral response to peripheral viral infection.

HSV-1 is the causative agent of cutaneous lesions, commonly referred to as cold sores. Primary exposure to the virus ordinarily occurs through the periphery, in particular through abraded skin or mucosal membranes. Under certain circumstances (e.g., in neonatals or AIDS patients), the infection becomes disseminated, often with severe consequences. Spread of HSV-1 is limited by virus-specific Ab. The development of an efficient humoral response to the virus is dependent on innate immunity component complement C3. The liver is the major source of C3, but there are also extrahepatic origins of C3 such as lymphoid macrophages. In the present study, the significance of C3 synthesis by bone marrow-derived cells was assessed by the transfer of wild-type bone marrow into irradiated C3-deficient mice. Using these chimeric mice, extrahepatic C3 was determined sufficient to initiate specific Ab and memory responses to a peripheral HSV-1 infection.

Construction, phenotypic analysis, and immunogenicity of a UL5/UL29 double deletion mutant of herpes simplex virus 2.

A number of studies have shown that replication-defective mutant strains of herpes simplex virus (HSV) can induce protective immunity in animal systems against wild-type HSV challenge. However, all of those studies used viruses with single mutations. Because multiple, stable mutations provide optimal levels of safety for live vaccines, we felt that additional mutations needed to be engineered into a candidate vaccine strain for HSV-2 and genital herpes. We therefore isolated an HSV-2 strain with deletion mutations in two viral DNA replication protein genes, UL5 and UL29. The resulting double deletion mutant virus strain, dl5-29, fails to form plaques or to give any detectable single cycle yields in normal monkey or human cells. Nevertheless, dl5-29 expresses nearly the same pattern of gene products as the wild-type virus or the single mutant viruses and induces antibody titers in mice that are equivalent to those induced by single deletion mutant viruses. Therefore, it is feasible to isolate a mutant HSV strain with two mutations in essential genes and with an increased level of safety but which is still highly immunogenic.

Humoral response to herpes simplex virus is complement-dependent.

The complement system represents a cascade of serum proteins, which provide a major effector function in innate immunity. Recent studies have revealed that complement links innate and adaptive immunity via complement receptors CD21/CD35 in that it enhances the B cell memory response to noninfectious protein antigens introduced i.v. To examine the importance of complement for immune responses to virus infection in a peripheral tissue, we compared the B cell memory response of mice deficient in complement C3, C4, or CD21/CD35 with wild-type controls. We found that the deficient mice failed to generate a normal memory response, which is characterized by a reduction in IgG antibody and germinal centers. Thus, complement is important not only in the effector function of innate immunity but also in the stimulation of memory B cell responses to viral-infected cell antigens in both blood and peripheral tissues.