Acceptability of intranasal live attenuated influenza vaccine, influenza knowledge and vaccine intent in The Gambia

Immunization-related stress and stress-related responses of mucosal versus intramuscular COVID-19 vaccination among adults in China

BACKGROUND

In late 2022, China became the first country to roll out mucosal COVID-19 vaccines. No prior study has yet compared the immunization stress-related responses (ISRR) among different routes of COVID-19 vaccine delivery. We aimed to compare the immunization-related psychological stress and ISRR between mucosal and intramuscular COVID-19 vaccines.

METHODS

A cross-sectional questionnaire survey using a biopsychosocial framework design was performed from January 11 to 20, 2023. Adults with COVID-19 vaccination were eligible for the study, and a total of 1073 adults participated with community-based sample. Primary outcomes were the psychological stress levels and prevalence of ISRR. Multivariate regression models were employed to compare these outcomes between the two vaccination groups. The potential mediating effects of stress on vaccination and ISRR were examined using bootstrap sampling method. To further ensure the robustness of our results, sensitivity analysis with propensity score matching was performed.

FINDINGS

In the univariate analysis, participants who received mucosal vaccination reported significantly lower stress levels compared to those who received intramuscular vaccination (3.39 ± 3.02 vs. 3.93 ± 3.24, P = .006). The prevalence of overall ISRR was significantly lower in the mucosal group compared to the intramuscular group (38.4% vs. 47.9%, P = .002). Multivariate regression models revealed that participants who received mucosal vaccination had a significantly lower stress level (β = -0.516, 95% CI: -0.852 to -0.180; P = .003) and 38.7% fewer overall ISRR (OR = 0.613, 95% CI: 0.427 to 0.881; P = .008), particularly in terms of neurological symptoms. The immunization-related stress mediated the association between vaccination type and ISRR, with indirect effects estimated at 0.0663 (95% CI: 0.0195 to 0.1346) for overall ISRR.

CONCLUSIONS

Mucosal COVID-19 vaccination was associated with reduced psychological stress and physical responses, as compared to intramuscular vaccination, which may contribute to increased trust and compliance with routine or mass vaccination efforts in the future.

A Questionnaire-based Study Exploring Participant Perspectives in a Perinatal Human Challenge Trial

BACKGROUND

Pregnant women have historically been excluded from most medical research, including human challenge studies. The proof-of-concept Lactamica 9 human challenge study investigated whether nasal inoculation of pregnant women with commensal bacteria leads to horizontal transmission to the neonate. Given the unique practical and ethical considerations of both human challenge studies and interventional research involving pregnant women and their newborns, we sought to investigate the motivations, concerns and experiences of these volunteers.

METHODS

Pre- and post-participation questionnaires were given to all participants in the Lactamica 9 study. These fully anonymized qualitative and Semi-quantitative questionnaires used forced Likert scales, word association and free-text questions.

RESULTS

Pre- and post-participation questionnaires were completed by 87.1% (27/31) and 62.5% (15/24) of eligible participants, respectively. Almost all pre-participation respondents agreed with altruistic motivations for participation, and most concerns were related to discomfort from study procedures, with few concerned about the theoretical risks of inoculation to themselves (5/27; 18.5%) or their baby (6/27; 22.2%). Participants most frequently associated the study intervention with the terms "bacteria," "natural," "protective" and "safe." For the post-participation questionnaire, 93.3% (14/15) found all study procedures acceptable, and qualitative feedback was almost entirely positive, with particular emphasis on the research team's flexibility, approachability and friendliness.

CONCLUSIONS

The successful completion of the Lactamica 9 study demonstrates that human challenge research in healthy pregnant women can be acceptable and feasible. Participants' initial concerns of potential discomfort were outweighed by predominantly altruistic motivations and perception of the intervention as "natural."

Determinants of maternal influenza vaccination in the context of low- and middle-income countries: A systematic review

BACKGROUND

Pregnancy and early infancy are considered to be the vulnerable phases for severe influenza infection causing morbidity and mortality. Despite WHO recommendations, influenza is not included in the immunization programs of many low- and middle-income countries. This systematic review is aimed at identifying barriers and facilitators for maternal influenza vaccination amongst the perinatal women and their health care providers in low- and middle-income countries.

METHODS

We selected 11 studies from the 1669 records identified from PubMed, CABI, EMBASE and Global Health databases. Studies related to both pandemic and routine influenza vaccination and studies conducted amongst women in the antenatal as well as postnatal period were included. Both qualitative, quantitative, cross-sectional and interventional studies were included.

RESULTS

Knowledge about influenza disease, perception of the disease severity during pregnancy and risk to the foetus/newborn and perceived benefits of influenza vaccination during pregnancy were associated with increased uptake of influenza vaccination during pregnancy. Recommendation by health care provider, vaccination in previous pregnancy and availability of vaccine in public health system facilitated vaccine uptake. High parity, higher education, vaccination in the later months of pregnancy, less than 4 antenatal visits, concerns about vaccine safety and negative publicity in media were identified as barriers for influenza vaccination. Lack of government recommendation, concerns about safety and effectiveness and distrust in manufacturer were the barriers for the healthcare providers to recommend vaccination.

CONCLUSION

While availability of influenza vaccine in public health system can be a key to the success of vaccine implementation program, increasing the awareness about need and benefits of maternal influenza vaccination amongst pregnant women as well as their health care providers is crucial to improve the acceptance of maternal influenza vaccination in low and middle-income countries.

The effect of live attenuated influenza vaccine on pneumococcal colonisation densities among children aged 24-59 months in The Gambia: a phase 4, open label, randomised, controlled trial

BACKGROUND

Influenza and other respiratory viruses promote Streptococcus pneumoniae proliferation in the upper respiratory tract. We sought to investigate for what we believe is the first time, the effect of intranasal live attenuated influenza vaccine (LAIV) on nasopharyngeal S pneumoniae density in a low-income to middle-income country population with high pneumococcal carriage rates.

METHODS

In an open-label, randomised, controlled trial in The Gambia, 330 healthy children aged 24-59 months were randomly assigned 2:1 to receive one trivalent LAIV dose at enrolment (day 0, intervention) or at the end of active follow-up (day 21, control). The investigator team were initially masked to block size and randomisation sequence to avoid allocation bias. Group allocation was later revealed to the investigator team. The primary outcome was PCR-quantified day 7 and 21 pneumococcal density. Asymptomatic respiratory viral infection at baseline and LAIV strain shedding were included as covariates in generalised mixed-effects models, to assess the effect of LAIV and other variables on pneumococcal densities. The study is registered at ClinicalTrials.gov, NCT02972957, and is closed to recruitment.

FINDINGS

Between Feb 8 and April 12, 2017, and Jan 15 and March 28, 2018, of 343 children assessed for eligibility, 213 in the intervention group and 108 in the control group completed the study and were included in the final analysis. Although no significant differences were seen in pneumococcal carriage or density at each timepoint when comparing groups, changes from baseline were observed in the LAIV group. The baseline S pneumoniae carriage prevalence was high in both LAIV and control groups (75%) and increased by day 21 in the LAIV group (85%, p=0·0037), but not in the control group (79%, p=0·44). An increase in pneumococcal density from day 0 amounts was seen in the LAIV group at day 7 (+0·207 log10 copies per μL, SE 0·105, p=0·050) and day 21 (+0·280 log10 copies per μL, SE 0·105, p=0·0082), but not in the control group. Older age was associated with lower pneumococcal density (-0·015 log10 copies per μL, SE 0·005, p=0·0030), with the presence of asymptomatic respiratory viruses at baseline (+0·259 log10 copies per μL, SE 0·097, p=0·017), and greater LAIV shedding at day 7 (+0·380 log10 copies per μL, SE 0·167, p=0·024) associated with higher pneumococcal density. A significant increase in rhinorrhoea was reported in the LAIV group compared with the control group children during the first 7 days of the study (103 [48%] of 213, compared with 25 [23%] of 108, p<0·0001), and between day 7 and 21 (108 [51%] of 213, compared with 28 [26%] of 108, p<0·0001).

INTERPRETATION

LAIV was associated with a modest increase in nasopharyngeal pneumococcal carriage and density in the 21 days following vaccination, with the increase in density lower in magnitude than previously described in the UK. This increase was accelerated when LAIV was administered in the presence of pre-existing asymptomatic respiratory viruses, suggesting that nasopharyngeal S pneumoniae proliferation is driven by cumulative mixed-viral co-infections. The effect of LAIV on pneumococcal density is probably similar to other respiratory viral infections in children. Our findings provide reassurance for the use of LAIV to expand influenza vaccine programmes in low-income to middle-income country populations with high pneumococcal carriage.

FUNDING

Wellcome Trust.

Using immunisation caregiver journey interviews to understand and optimise vaccination uptake: lessons from Sierra Leone

Quantitative and qualitative assessments have revealed diverse factors that influence the uptake of childhood immunisation services and shed light on reasons for vaccination delays and refusals. UNICEF and partner organisations developed the Immunisation Caregiver Journey Framework as a novel way to understand caregiver experiences in accessing and receiving immunisation services for children. This framework aims to help immunisation programmes identify vaccination barriers and opportunities to improve vaccination uptake by enhancing the overall caregiver journey in a systems-focused manner, using human-centred design principles. In this paper, we adapt the framework into a flexible qualitative inquiry approach with theoretical guidance from interpretative phenomenology. We draw from the implementation experiences in Sierra Leone to inform methodological guidance on how to design and implement the Immunisation Caregiver Journey Interviews (ICJI) to understand the lived experiences of caregivers as they navigate immunisation services for their children. Practical guidance is provided on sampling techniques, conducting interviews, data management, data analysis and the use of data to inform programmatic actions. When properly implemented, the ICJI approach generates a rich qualitative understanding of how caregivers navigate household and community dynamics, as well as primary healthcare delivery systems. We argue that understanding and improving the caregiver journey will enhance essential immunisation outcomes, such as the completion of the recommended vaccination schedule, timeliness of vaccination visits and reduction in dropouts between vaccine doses.

Towards Goals to Refine Prophylactic and Therapeutic Strategies Against COVID-19 Linked to Aging and Metabolic Syndrome

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) gave rise to the coronavirus disease 2019 (COVID-19) pandemic. A strong correlation has been demonstrated between worse COVID-19 outcomes, aging, and metabolic syndrome (MetS), which is primarily derived from obesity-induced systemic chronic low-grade inflammation with numerous complications, including type 2 diabetes mellitus (T2DM). The majority of COVID-19 deaths occurs in people over the age of 65. Individuals with MetS are inclined to manifest adverse disease consequences and mortality from COVID-19. In this review, we examine the prevalence and molecular mechanisms underlying enhanced risk of COVID-19 in elderly people and individuals with MetS. Subsequently, we discuss current progresses in treating COVID-19, including the development of new COVID-19 vaccines and antivirals, towards goals to elaborate prophylactic and therapeutic treatment options in this vulnerable population.

Factors influencing acceptance of vaccination during pregnancy in The Gambia and Senegal

BACKGROUND

Vaccination during pregnancy can protect pregnant women and their babies from infectious diseases. Tetanus vaccine, also known as tetanus toxoid, is the only vaccine given to pregnant women in The Gambia and Senegal, where it is given by antenatal care providers as part of the Expanded Programme on Immunization. A qualitative study was undertaken to explore factors influencing acceptance of vaccination during pregnancy in The Gambia and Senegal.

METHODS

Focus group discussions and in-depth interviews were conducted across urban and rural settlements of The Gambia and Senegal. We explored the knowledge, attitudes, and perceptions of 152 women who were either pregnant or with an infant. NVivo 11 Qualitative Data Analysis Software was used for management and thematic analysis of the data.

RESULTS

Women had sufficient knowledge of the need for tetanus vaccine from different information sources but insufficient knowledge of tetanus causes, signs and symptoms. Tetanus vaccine was perceived to be safe and side effects such as pain and swelling at site of injection did not deter uptake of future doses. Women overall had confidence in their sources of vaccine information and the health care workers who administered maternal vaccinations. Their willingness to accept vaccination during pregnancy was particularly influenced by their husbands and trusted healthcare workers. Women across all sites mentioned they would accept new maternal vaccines if they are sensitized beforehand about any potential risks and benefits to them and their babies.

CONCLUSION

Vaccine acceptance can be influenced by several factors including contextual, individual or group influences and vaccine or vaccination-specific issues. Women across The Gambia and Senegal are generally vaccine acceptors with confidence in the health care workers who vaccinate them and few concerns about maternal vaccines. Women's acceptance of vaccination during pregnancy is based on previous vaccination experiences and individual weighing of risks and benefits.

COVID-19 Vaccines (Revisited) and Oral-Mucosal Vector System as a Potential Vaccine Platform

There are several emerging strategies for the vaccination of COVID-19 (SARS-CoV-2) however, only a few have yet shown promising effects. Thus, choosing the right pathway and the best prophylactic options in preventing COVID-19 is still challenging at best. Approximately, more than two-hundred vaccines are being tested in different countries, and more than fifty clinical trials are currently undergoing. In this review, we have summarized the immune-based strategies for the development of COVID-19 vaccines and the different vaccine candidate platforms that are in clinical stages of evaluation, and up to the recently licensed mRNA-based COVID-19 vaccines of Pfizer-BioNtech and Moderna's. Lastly, we have briefly included the potentials of using the 'RPS-CTP vector system' for the development of a safe and effective oral mucosal COVID-19 vaccine as another vaccine platform.

The epidemiology of seasonal influenza after the 2009 influenza pandemic in Africa: a systematic review

Background

Influenza infection is a serious public health problem that causes an estimated 3 to 5 million cases and 250,000 deaths worldwide every year. The epidemiology of influenza is well-documented in high- and middle-income countries, however minimal effort had been made to understand the epidemiology, burden and seasonality of influenza in Africa. This study aims to assess the state of knowledge of seasonal influenza epidemiology in Africa and identify potential data gaps for policy formulation following the 2009 pandemic.

Method

We reviewed articles from Africa published into four databases namely: MEDLINE (PubMed), Google Scholar, Cochrane Library and Scientific Research Publishing from 2010 to 2019.

Results

We screened titles and abstracts of 2070 studies of which 311 were selected for full content evaluation and 199 studies were considered. Selected articles varied substantially on the basis of the topics they addressed covering the field of influenza surveillance (n=80); influenza risk factors and co-morbidities (n=15); influenza burden (n=37); influenza vaccination (n=40); influenza and other respiratory pathogens (n=22) and influenza diagnosis (n=5).

Conclusion

Significant progress has been made since the last pandemic in understanding the influenza epidemiology in Africa. However, efforts still remain for most countries to have sufficient data to allow countries to prioritize strategies for influenza prevention and control.

A systematic review of studies that measure parental vaccine attitudes and beliefs in childhood vaccination

Background

Acceptance of vaccines is an important predictor of vaccine uptake. This has public health implications as those who are not vaccinated are at a higher risk of infection from vaccine preventable diseases. We aimed to examine how parental attitudes and beliefs towards childhood vaccination were measured in questionnaires through a systematic review of the literature.

Methods

We systematically reviewed the literature to identify primary research studies using tools to measure vaccine attitudes and beliefs, published between January 2012 and May 2018. Studies were included if they involved a quantitative survey of the attitudes and beliefs of parents about vaccinations recommended for children. We undertook a synthesis of the results with a focus on evaluating the tools used to measure hesitancy.

Results

A total of 116 studies met the inclusion criteria, 99 used a cross sectional study design, 5 used a case control study design, 4 used a pre-post study design and 8 used mixed methods study designs. Sample sizes of included studies ranged from 49 to 12,259. The most commonly used tool was the Parent Attitudes about Childhood Vaccines (PACV) Survey (n = 7). The most common theoretical framework used was the Health Belief Model (n = 25). Questions eliciting vaccination attitudes and beliefs varied widely.

Conclusions

There was heterogeneity in the types of questionnaires used in studies investigating attitudes and beliefs about vaccination in parents. Methods to measure parental attitudes and beliefs about vaccination could be improved with validated and standardised yet flexible instruments. The use of a standard set of questions should be encouraged in this area of study.