Vaccine Development: From Laboratory to Policy

Designing a Recombinant Vaccine against Providencia rettgeri Using Immunoinformatics Approach

Antibiotic resistance (AR) is the resistance mechanism pattern in bacteria that evolves over some time, thus protecting the bacteria against antibiotics. AR is due to bacterial evolution to make itself fit to changing environmental conditions in a quest for survival of the fittest. AR has emerged due to the misuse and overuse of antimicrobial drugs, and few antibiotics are now left to deal with these superbug infections. To combat AR, vaccination is an effective method, used either therapeutically or prophylactically. In the current study, an in silico approach was applied for the design of multi-epitope-based vaccines against Providencia rettgeri, a major cause of traveler’s diarrhea. A total of six proteins: fimbrial protein, flagellar hook protein (FlgE), flagellar basal body L-ring protein (FlgH), flagellar hook-basal body complex protein (FliE), flagellar basal body P-ring formation protein (FlgA), and Gram-negative pili assembly chaperone domain proteins, were considered as vaccine targets and were utilized for B- and T-cell epitope prediction. The predicted epitopes were assessed for allergenicity, antigenicity, virulence, toxicity, and solubility. Moreover, filtered epitopes were utilized in multi-epitope vaccine construction. The predicted epitopes were joined with each other through specific GPGPG linkers and were joined with cholera toxin B subunit adjuvant via another EAAAK linker in order to enhance the efficacy of the designed vaccine. Docking studies of the designed vaccine construct were performed with MHC-I (PDB ID: 1I1Y), MHC-II (1KG0), and TLR-4 (4G8A). Findings of the docking study were validated through molecular dynamic simulations, which confirmed that the designed vaccine showed strong interactions with the immune receptors, and that the epitopes were exposed to the host immune system for proper recognition and processing. Additionally, binding free energies were estimated, which highlighted both electrostatic energy and van der Waals forces to make the complexes stable. Briefly, findings of the current study are promising and may help experimental vaccinologists to formulate a novel multi-epitope vaccine against P. rettgeri.

Should nurses take a COVID-19 vaccine?

The issue as to whether health care professionals have a moral obligation to take a vaccine for a communicable disease is not new. Nonetheless, this issue takes on a fresh urgency within nursing practice in the context of the present COVID-19 pandemic, i.e., is there an ethical requirement for nurses to take a COVID-19 vaccine? This paper approaches the issue by using a hypothetical example of Nurse X who has inadvertently infected Patient Y. French's (1984a) Principle of Responsive Adjustment is adapted to claim that there would be a moral expectation that Nurse X takes a COVID-19 vaccine (unless there are justifiable reasons not to). The proposition is also made that, should Nurse X not take a COVID-19 vaccine, they could be morally associated with originally infecting Patient Y.

The Role of Trauma in Mothers' COVID-19 Vaccine Beliefs and Intentions

OBJECTIVE

Research on COVID-19 vaccine beliefs has focused primarily on adults' intentions to vaccinate themselves; however, many parents will also face decisions about vaccinating their children. In this study, we examine how maternal posttraumatic stress disorder (PTSD) and trauma history relate to mothers' beliefs and intentions about the COVID-19 vaccine for themselves and their children.

METHODS

A total of 240 mothers with a mental health history participating in a parenting study answered online survey questions via Prolific. Questions assessed: (a) trauma indictors (past diagnosis, current symptoms, and lifetime exposure to events); (b) vaccine measures (intentions for self and child, COVID-19 vaccine confidence, general vaccine perceived safety, reasoning about vaccine intentions, sources of influence on intentions); and (c) possible explanatory variables (institutional distrust, negative worldviews). ANCOVAs and regression analyses were used.

RESULTS

When compared with mothers with other mental health diagnoses, mothers with a PTSD history had significantly less confidence in the COVID-19 vaccine and less intent to get the vaccine for themselves or their child. These effects were explained by greater institutional distrust (i.e., significant indirect effects). Mothers with a previous PTSD diagnosis also expressed different reasons for vaccine hesitancy (e.g., less belief in science) and ascribed less influence to healthcare and governmental sources in vaccine decision-making.

CONCLUSION

Findings highlight the potential utility of a trauma-informed approach in efforts to reduce COVID-19 vaccine hesitancy. For mothers with a history of PTSD, addressing institutional distrust, including towards the healthcare industry, may be an important element to consider in the content, delivery, and mode of vaccine messaging.