Browsing by Subject "vaccine"

Now showing 1 - 7 of 7
  • Thumbnail Image
    Item
    Achieving an Optimal Childhood Vaccine Policy
    (American Medical Association, 2017-09-01) Opel, Douglas J.; Schwartz, Jason L.; Omer, Saad B.; Silverman, Ross D.; Duchin, Jeff; Kodish, Eric; Diekema, Douglas S.; Marcuse, Edgar K.; Orenstein, Walt; Health Policy and Management, School of Public Health
    Policies to remove parents' ability to opt-out from school immunization requirements on the basis of religious or personal beliefs (ie, nonmedical exemptions) may be a useful strategy to increase immunization rates and prevent outbreaks of vaccine-preventable disease. However, there is uncertainty about the effectiveness of this strategy and the range of possible outcomes. We advocate for a more deliberative process through which a broad range of outcomes is scrutinized and the balance of values underlying the policy decision to eliminate nonmedical exemptions is clearly articulated. We identify 3 outcomes that require particular consideration before policies to eliminate nonmedical exemptions are implemented widely and outline a process for making the values underlying such policies more explicit.
  • Thumbnail Image
    Item
    From “A Spoonful of Sugar” to Operation Warp Speed: COVID-19 Vaccines and Their Metaphors
    (Harvard Law School, 2020-12-15) Silverman, Ross D.; Head, Katharine J.; Beckman, Emily; Health Policy and Management, School of Public Health
    We must remain cognizant of the many ways metaphors may distort, divide, or misrepresent important details.
  • Thumbnail Image
    Item
    Global Delivery of Human Papillomavirus Vaccines
    (Elsevier, 2016-02) Wigle, Jannah; Fontenot, Holly B.; Zimet, Gregory D.; Department of Pediatrics, IU School of Medicine
    Worldwide, cervical cancer is the fourth most common cancer among women, with over half a million women diagnosed with cervical cancer in 2012. Human papillomavirus (HPV) vaccination, if broadly implemented, has the potential to significantly reduce global rates of morbidity and mortality associated with cervical and other HPV-related cancers. Over 100 countries around the world have licensed HPV vaccines. As of February, 2015, there were an estimated 80 national HPV immunization programs and 37 pilot programs, including many implemented in low- and middle-income countries. In this article, global implementation of HPV vaccination programs is discussed, including successes and ongoing challenges. Issues such as vaccine financing and different approaches to HPV vaccine delivery are presented.
  • Thumbnail Image
    Item
    Longitudinal IgG antibody responses to Plasmodium vivax blood-stage antigens during and after acute vivax malaria in individuals living in the Brazilian Amazo
    (PLoS, 2022-11-23) Tashi, Tenzin; Upadhye, Aditi; Kundu, Prasun; Wu, Chunxiang; Menant, Sébastien; Soares, Roberta Reis; Ferreira, Marcelo U.; Longley, Rhea J.; Mueller, Ivo; Hoang, Quyen Q.; Tham, Wai-Hong; Rayner, Julian C.; Scopel, Kézia K. G.; Lima-Junior, Josué C.; Tran, Tuan M.; Medicine, School of Medicine
    Background To make progress towards malaria elimination, a highly effective vaccine targeting Plasmodium vivax is urgently needed. Evaluating the kinetics of natural antibody responses to vaccine candidate antigens after acute vivax malaria can inform the design of serological markers of exposure and vaccines. Methodology/Principal findings The responses of IgG antibodies to 9 P. vivax vaccine candidate antigens were evaluated in longitudinal serum samples from Brazilian individuals collected at the time of acute vivax malaria and 30, 60, and 180 days afterwards. Antigen-specific IgG correlations, seroprevalence, and half-lives were determined for each antigen using the longitudinal data. Antibody reactivities against Pv41 and PVX_081550 strongly correlated with each other at each of the four time points. The analysis identified robust responses in terms of magnitude and seroprevalence against Pv41 and PvGAMA at 30 and 60 days. Among the 8 P. vivax antigens demonstrating >50% seropositivity across all individuals, antibodies specific to PVX_081550 had the longest half-life (100 days; 95% CI, 83–130 days), followed by PvRBP2b (91 days; 95% CI, 76–110 days) and Pv12 (82 days; 95% CI, 64–110 days). Conclusion/Significance This study provides an in-depth assessment of the kinetics of antibody responses to key vaccine candidate antigens in Brazilians with acute vivax malaria. Follow-up studies are needed to determine whether the longer-lived antibody responses induced by natural infection are effective in controlling blood-stage infection and mediating clinical protection.
  • Thumbnail Image
    Item
    Recent advances in vaccine and immunotherapy for COVID-19
    (Taylor & Francis, 2020) Rabaan, Ali A.; Al-Ahmed, Shamsah H.; Sah, Ranjit; Al-Tawfiq, Jaffar A.; Al-Qaneh, Ayman M.; Al-Jamea, Lamiaa H.; Woodman, Alexander; Al-Qahtani, Manaf; Haque, Shafiul; Harapan, Harapan; Bonilla-Aldana, D. Katterine; Kumar, Pavan; Dhama, Kuldeep; Rodriguez-Morales, Alfonso J.; Medicine, School of Medicine
    The COVID-19 pandemic caused by SARS-CoV-2 has resulted in millions of cases and hundreds of thousands of deaths. Beyond there being no available antiviral therapy, stimulating protective immunity by vaccines is the best option for managing future infections. Development of a vaccine for a novel virus is a challenging effort that may take several years to accomplish. This mini-review summarizes the immunopathological responses to SARS-CoV-2 infection and discusses advances in the development of vaccines and immunotherapeutics for COVID-19.
  • Thumbnail Image
    Item
    Risk perceptions after human papillomavirus vaccination are not subsequently associated with riskier behaviors or sexually transmitted infections in HIV-infected young women
    (Taylor & Francis, 2019-06-03) Thomas, Rachel; Dillard, Mary; Xu, Jiahong; Zimet, Gregory D.; Kahn, Jessica A.; Pediatrics, School of Medicine
    Concerns have been raised that risk perceptions after human papillomavirus (HPV) vaccination may lead to riskier sexual behaviors or sexually transmitted infection (STI) diagnosis. The aims of this study were to determine whether risk perceptions immediately after HPV vaccination (perceived risk of HPV, perceived risk of STIs other than HPV, and perceived need for safer sexual behaviors, measured using 5-item scales) were associated with number of sexual partners, condom use at last sexual intercourse, or STI diagnosis over the subsequent 48 weeks in HIV-infected young women (N = 99, 17–24 years of age) participating in an HPV vaccine clinical trial. Generalized estimating equation models demonstrated that lower perceived need for safer sexual behaviors was associated subsequently with lower total number of sexual partners (adjusted odds ratio (AOR) = 1.05, 95% confidence interval (CI) = 1.01–1.09) and lower perceived risk of HPV was associated with subsequent report of having used condoms at last sex (AOR = 0.36, AOR = 0.14–0.92). Lower perceived risk of other STIs was not associated with subsequent sexual behaviors. None of the three risk perceptions was associated with subsequent risk of STIs. The findings suggest that inappropriate risk perceptions after HPV vaccination such as lower perceived need for safer sexual behaviors and lower perceived risk of HPV or other STIs were not subsequently associated with risky behaviors or STI diagnosis in HIV-infected young women.
  • Thumbnail Image
    Item
    Synergistic malaria vaccine combinations identified by systematic antigen screening
    (National Academy of Sciences, 2017-11-07) Bustamante, Leyla Y.; Powell, Gareth T.; Lin, Yen-Chun; Macklin, Michael D.; Cross, Nadia; Kemp, Alison; Cawkill, Paula; Sanderson, Theo; Crosnier, Cecile; Muller-Sienerth, Nicole; Doumbo, Ogobara K.; Traore, Boubacar; Crompton, Peter D.; Cicuta, Pietro; Tran, Tuan M.; Wright, Gavin J.; Rayner, Julian C.; Medicine, School of Medicine
    Malaria still kills hundreds of thousands of children each year. Malaria vaccine development is complicated by high levels of parasite genetic diversity, which makes single target vaccines vulnerable to the development of variant-specific immunity. To overcome this hurdle, we systematically screened a panel of 29 blood-stage antigens from the most deadly human malaria parasite, Plasmodium falciparum. We identified several targets that were able to inhibit erythrocyte invasion in two genetically diverse strains. Testing these targets in combination identified several pairs that blocked invasion more effectively in combination than in isolation. Video microscopy and studies of natural immune responses to malaria in patients suggest that targeting multiple steps in invasion is more likely to produce a synergistic vaccine response., A highly effective vaccine would be a valuable weapon in the drive toward malaria elimination. No such vaccine currently exists, and only a handful of the hundreds of potential candidates in the parasite genome have been evaluated. In this study, we systematically evaluated 29 antigens likely to be involved in erythrocyte invasion, an essential developmental stage during which the malaria parasite is vulnerable to antibody-mediated inhibition. Testing antigens alone and in combination identified several strain-transcending targets that had synergistic combinatorial effects in vitro, while studies in an endemic population revealed that combinations of the same antigens were associated with protection from febrile malaria. Video microscopy established that the most effective combinations targeted multiple discrete stages of invasion, suggesting a mechanistic explanation for synergy. Overall, this study both identifies specific antigen combinations for high-priority clinical testing and establishes a generalizable approach that is more likely to produce effective vaccines.