| 1. |
- Viegas, Edna Omar
(författare)
-
Human immunodeficiency virus and human papillomavirus infections in Mozambique : from epidemiological reports to clinical trials and vaccine implementation
- 2017
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Human immunodeficiency virus (HIV) and human papillomavirus (HPV) are sexually transmitted microorganisms responsible for two major infectious diseases and public health concerns, particularly in developing countries and in sub-Saharan Africa. HIV is the causative agent of the acquired immunodeficiency syndrome (AIDS) that has so far claimed more than 35 million lives. HPV is responsible for virtually all cervical cancers (CC), the seventh most common cancer in the world and the fourth in women. Mozambique is highly affected by both HIV and HPV epidemics. The country has the fifth highest prevalence of HIV in the world and the second highest rates of CC in Africa. The national seroprevalence of HIV in 2015 was estimated to be 13.2% in populations aged 15-49 years. A previous report from Southern Mozambique has demonstrated a high prevalence of HPV in women aged 14-61 years (75.9%). This thesis aimed at describing the epidemiology of HIV and HPV infections in young adults in Maputo city, Mozambique and to evaluate preventive strategies for control of HIV and HPV. This thesis embraces a total of four studies (I-IV). Study I aimed at determining the HIV incidence in youths aged 18-24 years. In this study 1380 subjects were screened for HIV, hepatitis B virus and syphilis. HIV-uninfected individuals (n=1309) were prospectively followed for one year with quarterly study visits to determine the HIV status. The HIV, hepatitis B and syphilis prevalence found at baseline were 5.1%, 12.2% and 0.36%, respectively. The overall HIV incidence was 1.14/100 PY and was slightly higher in the female population (1.49/100 WY). The relatively low prevalence and incidence of HIV and the low prevalence of syphilis described in this study associated to the considerable stable visit retention rates, suggest that this cohort is suitable for recruitment into phase I/II HIV vaccine trials. Study II was a phase I HIV vaccine trial that recruited 24 healthy HIV-uninfected individuals from the cohort established in study I and aimed at exploring the safety and immunogenicity of an HIV-DNA/HIV-MVA prime-boost strategy using a low-dose (600 μg, 2 x 0.1 mL) and a high-dose (1200 μg, 2 x 0.2 mL) of HIV-DNA prime, delivered intradermally using a needle-free device, the ZetajetTM. This was the first HIV vaccine trial ever conducted in Mozambique and the first to assess the use of the ZetajetTM in a higher injection volume. The vaccines were safe and well tolerated. After the first HIV-MVA, Env responses were significantly higher in the high-dose group compared to the low-dose group (median 420 vs. 157.5 SFC/million PBMC, p = 0.014). Four weeks after the 2nd HIV-MVA, binding antibodies to recombinant CN54 subtype C gp140 and to native subtype B gp160 were induced in all vaccinees, with a median titer of 800 and 400, respectively. The findings suggest that the higher 1200 μg HIV-DNA dose should be considered in the future. Study III describes HPV genotypes in young women and men recruited from the cohort established in study I. Cervical and urethral samples were collected in women and men, respectively and analyzed using the Clart® Human Papillomavirus 2 (Genomica, Madrid, Spain), a target amplification assay capable of detecting 35 different low- and high-risk HPV genotypes. The overall prevalence of HPV was 40.8% (63.6% and 10.2% in women and men, respectively). In women HPV52, 35, 16, 53, 58, 6, and 51 were the most frequently found genotypes and HPV6, 11, 52, 59, and 70 in men. These results show a 50% homology with the genotypes detected in CC specimens in the country. Study IV was a two-round post-vaccination survey conducted after an HPV vaccine demonstration project (in 2014 and 2015), in which an HPV vaccine was given to girls aged 9-10 years, in two rural districts of Mozambique (Manica and Mocímboa da Praia). This study aimed at assessing the HPV vaccine coverage, awareness, knowledge, and acceptance; to explore reasons for not-vaccinating; and to identify the best vaccine communication strategies. Parents or guardians of girls eligible for vaccination were interviewed within 4 months after the last HPV injection had been administered to the girls. Vaccine coverage in 2014 was 50% and 14% and in 2015 was 47% and 32% for Manica and Mocímboa da Praia, respectively. The most frequent reason to vaccinate the girls was the belief that the vaccine could contribute to the girl´s health. The reasons for not vaccinating were the absence of girls from school and the lack of knowledge about the campaign. The radio spot was the communication strategy that reached the majority of respondents. These results show that provision of information about the benefits of vaccines can lead to a positive decision by the parents/guardians and improved planning and communications may increase the vaccination rates. Lessons learned from this study may give important insights on the implementation of a future HIV vaccine in adolescents, a group that will most likely be prioritized.
|
|
| 2. |
- Viegas, Edna Omar, et al.
(författare)
-
Human papillomavirus prevalence and genotype distribution among young women and men in Maputo city, Mozambique
- 2017
-
Ingår i: BMJ Open. - : BMJ Publishing Group Ltd. - 2044-6055. ; 7:7
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: Human papillomavirus (HPV) is a well-known cause of cervical cancer, the second most frequent cancer in female African populations. This study aimed at determining the prevalence of HPV infections and the genotype distribution in young adults aged 18-24, in Maputo city, Mozambique, and to assess the suitability of commercially available HPV vaccines.METHODS: This cross-sectional study was conducted between 2009 and 2011 at a youth clinic in Maputo Central Hospital. Cervical and urethral samples were obtained from 236 women and 176 men, respectively. Demographic and behavioural data were collected using structured questionnaires. HPV genotyping was performed for 35 different high, probably or possibly high-risk and low-risk HPV types using the CLART Human Papillomavirus 2.RESULTS: HPV prevalence was 168/412 (40.8%; 95% CI 36.0 to 45.5) and was significantly higher in women than in men (63.6%vs10.2%). HPV52 was the most frequent type found in women, followed by HPV35, -16,-53, -58,-6 and -51. In men, HPV51 ranked the highest, followed by HPV6, -11,-52, -59 and -70. HIV infection and sexual debut before 18 years of age were associated with multiple HPV infections (OR 3.03; 95% CI 1.49 to 6.25 and OR 6.03; 95% CI 1.73 to 21.02, respectively). Women had a significantly higher HPV infection prevalence than men (p<0.001). The 9-valent HPV vaccine would cover 36.8% of the high-risk genotypes circulating in women in this study, compared with 26.3% and 15.8% coverage by the bivalent and quadrivalent vaccines, respectively.CONCLUSION: This study confirmed the high burden of HPV infections in young women in Maputo city, Mozambique. The HPV prevalence was associated with high-risk sexual behaviour. Sex education and sexually transmitted infection prevention interventions should be intensified in Mozambique. Only a proportion of the high-risk HPV genotypes (37%) were covered by currently available vaccines.
|
|
| 3. |
- Viegas, Edna Omar, et al.
(författare)
-
Incidence of HIV and the Prevalence of HIV, Hepatitis B and Syphilis among Youths in Maputo, Mozambique : A Cohort Study
- 2015
-
Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 10:3
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Prevalence of HIV in Mozambique among individuals aged 15-49 years is 11.5%. The HIV prevalence is higher in women than in men across the country, peaking at ages 25-29 years and 35-39 years, respectively. In this study, we aimed at determining the prevalence and incidence of HIV, prevalence of Hepatitis B (HBV), and prevalence of syphilis in youths. We also characterized a cohort of youths for future participation in phase I/II HIV vaccine trials.Methods: The study was conducted at a youth clinic in Maputo Central Hospital from August 2009 to October 2011. Youths of both genders aged 18-24 years (n = 1380) were screened for HIV using a sequential algorithm of two immunochromatographic assays, HBV using an enzyme linked immunosorbant test, and syphilis using a treponemal immunochromatographic strip test. The HIV seronegative participants (n = 1309) were followed-up for 12 months with quarterly study visits. The clinical and behavioral data were collected using structured questionnaires. The HIV seroconversions were confirmed by a molecular assay.Results: The study population was female dominant (76.8%). All participants had a formal education, with 44.6% studying for technical or higher education degrees. The mean age at sexual debut was 16.6 years (SD: +/-1.74), with 85.6% reporting more than one sexual partner in life. The screening showed the prevalence of HIV, HBV, and syphilis at 5.1% (95% CI: 3.97-6.31), 12.2% (95% CI 10.5%-14.0%), and 0.36% (95% CI 0.15%-0.84%), respectively. The HIV incidence rate was found to be 1.14/100 person years (95% CI: 0.67-1.92). Retention rates were stable throughout the study being 85.1% at the last visit.Conclusion: Incidence of HIV in this cohort of youths in Maputo was relatively low. Also, the prevalence of HIV and syphilis was lower than the national values in this age group. However, the HBV prevalence was higher than in previous reports in the country.
|
|
| 4. |
- Viegas, Edna Omar, et al.
(författare)
-
Intradermal HIV-1 DNA immunization using needle-free ZetajetTM injection followed by HIV-modified vaccinia virus Ankara vaccination is safe and immunogenic in Mozambican young adults : a phase I randomized controlled trial
- 2018
-
Ingår i: AIDS Research and Human Retroviruses. - : Mary Ann Liebert. - 0889-2229 .- 1931-8405. ; 34:2, s. 193-205
-
Tidskriftsartikel (refereegranskat)abstract
- We assessed safety and immunogenicity of HIV-DNA priming using ZetajetTM, a needle-free device intradermally followed by intramuscular HIV-MVA boosts, in 24 healthy Mozambicans. Volunteers were randomized to receive three immunizations of 600 µg (n = 10; 2 x 0.1mL) or 1200 µg (n = 10; 2 x 0.2mL) of HIV-DNA (3 mg/mL), followed by two boosts of 108pfu HIV-MVA. Four subjects received placebo saline injections. Vaccines and injections were safe and well tolerated with no difference between the two priming groups. After three HIV-DNA immunizations, IFN-γ ELISpot responses to Gag were detected in 9/17 (53%) vaccinees, while none responded to Env. After the first HIV-MVA, the overall response rate to Gag and/or Env increased to 14/15 (93%); 14/15 (93%) to Gag and 13/15 (87%) to Env. There were no significant differences between the immunization groups in frequency of response to Gag and Env or magnitude of Gag responses. Env responses were significantly higher in the higher-dose group (median 420 vs 157.5 SFC/million PBMC, p=0.014). HIV-specific antibodies to subtype C gp140 and subtype B gp160 were elicited in all vaccinees after the second HIV-MVA, without differences in titers between the groups. Neutralizing antibody responses were not detected. Two (13%) of 16 vaccinees, one in each of the priming groups, exhibited antibodies mediating antibody-dependent cellular cytotoxicity to CRF01_AE. In conclusion, HIV-DNA vaccine delivered intradermally in volumes of 0.1-0.2 mL using ZetajetTM was safe and well tolerated. Priming with the 1200 µg dose of HIV-DNA generated higher magnitudes of ELISpot responses to Env.
|
|
