A comprehensive review of vaccination in patients with inflammatory bowel diseases: An Indian perspective.

The disease burden of inflammatory bowel diseases (IBD) in India is estimated to be one of the highest in the world in the near future. Patients with IBD, particularly those on immunosuppressive therapy, are at increased risk for developing vaccine-preventable illnesses. Adult vaccination policy and vaccination in patients with IBD are presently being at a very low level in India. This review discusses in detail the need for vaccination, levels of immunosuppression, a brief account of live and inactivated vaccines, available vaccines, and their utility in patients with IBD, with a special focus on recent recommendations.

Vaccination coverage survey and seroprevalence among forcibly displaced Rohingya children, Cox's Bazar, Bangladesh, 2018: A cross-sectional study.

BACKGROUND: During August 2017-January 2018, more than 700,000 forcibly displaced Rohingyas crossed into Cox's Bazar, Bangladesh. In response to measles and diphtheria cases, first documented in September and November 2017, respectively, vaccination campaigns targeting children <15 years old were mobilized during September 2017-March 2018. However, in a rapidly evolving emergency situation, poor sanitation, malnutrition, overcrowding, and lack of access to safe water and healthcare can increase susceptibility to infectious diseases, particularly among children. We aimed to estimate population immunity to vaccine-preventable diseases (VPDs) after vaccination activities in the camps to identify any remaining immunity gaps among Rohingya children. METHODS AND FINDINGS: We conducted a cross-sectional serologic and vaccination coverage survey in Nayapara Registered Refugee Camp ("Nayapara") and makeshift settlements (MSs) April 28, 2018 to May 31, 2018, among 930 children aged 6 months to 14 years. MSs are informal, self-settled areas with a population of more than 850,000, the majority of whom arrived after August 2017, whereas Nayapara is a registered camp and has better infrastructure than MSs, including provision of routine immunization services. Households were identified using simple random sampling (SRS) in Nayapara and multistage cluster sampling in MSs (because household lists were unavailable). Dried blood spots (DBSs) were collected to estimate seroprotection against measles, rubella, diphtheria, and tetanus, using Luminex multiplex bead assay (MBA). Caregiver interviews assessed vaccination campaign participation using vaccination card or recall. In Nayapara, 273 children aged 1 to 6 years participated; 46% were female and 88% were registered refugees. In MSs, 358 children aged 1 to 6 years and 299 children aged 7 to 14 years participated; 48% of all children in MSs were female, and none were registered refugees. In Nayapara, estimated seroprotection among 1- to 6-year-olds was high for measles, rubella, diphtheria, and tetanus (91%-98%; 95% confidence interval [CI] 87%-99%); children >6 years were not assessed. In MSs, measles seroprotection was similarly high among 1- to 6-year-olds and 7- to 14-year-olds (91% [95% CI 86%-94%] and 99% [95% CI 96%-100%], respectively, p < 0.001). Rubella and diphtheria seroprotection in MSs were significantly lower among 1- to 6-year-olds (84% [95% CI 79%-88%] and 63% [95% CI 56%-70%]) compared to 7- to 14-year-olds (96% [95% CI 90%-98%] and 77% [95% CI 69%-84%]) (p < 0.001). Tetanus seroprevalence was similar among 1- to 6-year-olds and 7- to 14-year-olds (76% [95% CI 69%-81%] and 84% [95% CI 77%-89%], respectively; p = 0.07). Vaccination campaign coverage was consistent with seroprotection in both camps. However, nonresponse, the main limitation of the study, may have biased the seroprotection and campaign coverage results. CONCLUSIONS: In this study, we observed that despite multiple vaccination campaigns, immunity gaps exist among children in MSs, particularly for diphtheria, which requires serial vaccinations to achieve maximum protection. Therefore, an additional tetanus-diphtheria campaign may be warranted in MSs to address these remaining immunity gaps. Rapid scale-up and strengthening of routine immunization services to reach children and to deliver missed doses to older children is also critically needed to close immunity gaps and prevent future outbreaks.

Adjuvant Systems for vaccines: 13 years of post-licensure experience in diverse populations have progressed the way adjuvanted vaccine safety is investigated and understood.

Adjuvant Systems (AS) are combinations of immune stimulants that enhance the immune response to vaccine antigens. The first vaccine containing an AS (AS04) was licensed in 2005. As of 2018, several vaccines containing AS04, AS03 or AS01 have been licensed or approved by regulatory authorities in some countries, and included in vaccination programs. These vaccines target diverse viral and parasitic diseases (hepatitis B, human papillomavirus, malaria, herpes zoster, and (pre)pandemic influenza), and were developed for widely different target populations (e.g. individuals with renal impairment, girls and young women, infants and children living in Africa, adults 50 years of age and older, and the general population). Clearly, the safety profile of one vaccine in one target population cannot be extrapolated to another vaccine or to another target population, even for vaccines containing the same adjuvant. Therefore, the assessment of adjuvant safety poses specific challenges. In this review we provide a historical perspective on how AS were developed from the angle of the challenges encountered on safety evaluation during clinical development and after licensure, and illustrate how these challenges have been met to date. Methods to evaluate safety of adjuvants have evolved based on the availability of new technologies allowing a better understanding of their mode of action, and new ways of collecting and assessing safety information. Since 2005, safety experience with AS has accumulated with their use in diverse vaccines and in markedly different populations, in national immunization programs, and in a pandemic setting. Thirteen years of experience using antigens combined with AS attest to their acceptable safety profile. Methods developed to assess the safety of vaccines containing AS have progressed the way we understand and investigate vaccine safety, and have helped set new standards that will guide and support new candidate vaccine development, particularly those using new adjuvants. FOCUS ON THE PATIENT: What is the context? Adjuvants are immunostimulants used to modulate and enhance the immune response induced by vaccination. Since the 1990s, adjuvantation has moved toward combining several immunostimulants in the form of Adjuvant System(s) (AS), rather than relying on a single immunostimulant. AS have enabled the development of new vaccines targeting diseases and/or populations with special challenges that were previously not feasible using classical vaccine technology. What is new? In the last 13 years, several AS-containing vaccines have been studied targeting different diseases and populations. Over this period, overall vaccine safety has been monitored and real-life safety profiles have been assessed following routine use in the general population in many countries. Moreover, new methods for safety assessment, such as a better determination of the mode of action, have been implemented in order to help understand the safety characteristics of AS-containing vaccines. What is the impact? New standards and safety experience accumulated over the last decade can guide and help support the safety assessment of new candidate vaccines during development.

Resurgence of Vaccine-Preventable Diseases in Venezuela as a Regional Public Health Threat in the Americas.

Venezuela's tumbling economy and authoritarian rule have precipitated an unprecedented humanitarian crisis. Hyperinflation rates now exceed 45,000%, and Venezuela's health system is in free fall. The country is experiencing a massive exodus of biomedical scientists and qualified healthcare professionals. Reemergence of arthropod-borne and vaccine-preventable diseases has sparked serious epidemics that also affect neighboring countries. In this article, we discuss the ongoing epidemics of measles and diphtheria in Venezuela and their disproportionate impact on indigenous populations. We also discuss the potential for reemergence of poliomyelitis and conclude that action to halt the spread of vaccine-preventable diseases within Venezuela is a matter of urgency for the country and the region. We further provide specific recommendations for addressing this crisis.

Vaccine-preventable diseases, vaccines and Guillain-Barre' syndrome.

Guillain-Barré syndrome (GBS) is an acute, immune-mediated polyradiculoneuropathy. Infections and vaccines have been hypothesized to play a role in triggering GBS development. These beliefs can play a role in reducing vaccination coverage. In this report, data concerning this hypothesis are discussed. It is shown that an association between vaccine administration and GBS has never been proven for most of debated vaccines, although it cannot be definitively excluded. The only exception is the influenza vaccine, at least for the preparation used in 1976. For some vaccines, such as measles/mumps/rubella, human papillomavirus, tetravalent conjugated meningococcal vaccine, and influenza, the debate between supporters and opponents of vaccination remains robust and perception of vaccines' low safety remains a barrier to achieving adequate vaccination coverage. Less than 1 case of GBS per million immunized persons might occur for these vaccines. However, in some casesimmunization actually reduces the risk of GBS development. In addition, the benefits of vaccination are clearly demonstrated by the eradication or enormous decline in the incidence of many vaccine-preventable diseases. These data highlight that the hypothesized risks of adverse events, such as GBS, cannot be considered a valid reason to avoid the administration of currently recommended vaccines.