Targeted Vaccination Strategies Research Articles

P-166. Susceptibility to Measles among immigrants in South Korea

Abstract Background Despite the World Health Organization's declaration of measles elimination in Korea in 2014, the country continues to encounter outbreaks, predominantly from cases imported via international travel. This study investigates the susceptibility to measles among immigrants residing in Korea, with an emphasis on their immunity status. Methods Conducted in Gwangju, Republic of Korea, this research measured measles immunoglobulin G (IgG) serum levels among immigrants from various nationalities. Results The study enrolled 415 participants, predominantly from Vietnam (18.8%), Uzbekistan (17.1%), Kazakhstan (10.4%), and the Russian Federation (10.1%). Overall, 82.2% exhibited seropositivity for measles IgG. Individuals under 30 years showed significantly lower seroprevalence at 61.8%, compared to 90.8% in those aged 30 and above. The lowest seroprevalences were noted in Cambodia (64.9%), the Russian Federation (69.8%), Ukraine and Mongolia (71.4% each), Nepal (75.0%), Kazakhstan (76.7%), and Uzbekistan (86.5%). The countries with the largest gaps from WHO/UNICEF published MCV2 coverage rates were Russian Federation and Mongolia (average MCV2 coverage rate 95.9% and 95.5% from 2000 to 2022, respectively). There were also significant disparities in measles immunity based on visa types, with work visa holders showing considerably lower immunity (75%) compared to those with residence visas (87.2%; Chi-square test, P=0.02). Conclusion The results highlight significant disparities in measles immunity among immigrants, particularly according to age, countries, and visas. The study underscores the critical need for targeted vaccination strategies and enhanced surveillance in Korea. Implementing tailored catch-up vaccination programs is essential to reduce the risk of measles outbreaks within this vulnerable population. Disclosures All Authors: No reported disclosures

P-1395. Safety and Effectiveness of LC16m8 for Pre-Exposure Prophylaxis Against mpox in High-Risk Population: An Open-Label Randomized Trial

Abstract Background Since May 2022, the incidence of mpox cases has surged outside endemic regions. Although vaccination remains pivotal in mpox prevention, data on LC16m8, a third-generation smallpox vaccine, are scant. We provided LC16m8 pre-exposure prophylaxis opportunities to high-risk individuals, including those with HIV, and conducted a randomized controlled trial to assess LC16m8’s effectiveness in mpox prevention and safety. Methods Our multicenter randomized open-label trial enrolled men and women aged ≥18 years at high mpox risk who provided written consent. Participants were randomly assigned 1:1 to early or late vaccination groups, receiving vaccinations approximately 70 days apart. Primary endpoint: vaccine effectiveness (VE) against mpox development between early and late vaccinations. VE against severe mpox, symptoms, “take” incidence, and adverse events were secondary endpoints. Results A total of 1,135 participants were recruited; 570 and 565 were assigned to early and late vaccination groups, respectively; 530 and 476 were vaccinated. Median age: 41 years; 99.7% were male; 89.7% Japanese; and 34.4% HIV-infected. No mpox cases occurred during the observation period, precluding VE calculation. “Take” rates: 90.3% (HIV-infected), 94.6% (uninfected). Adverse events related to the study were observed in 96.6% and 98.0% of the HIV-infected and uninfected participants, respectively. No fatal adverse events were observed; serious adverse events (SAE): 0.6% (HIV-infected), 0.5% (uninfected). One HIV-uninfected participant reported pulmonary embolism and deep vein thrombosis as a causally undeniable SAE. Local skin reactions: 96.6% (HIV-infected), 97.9% (uninfected); systemic reactions: 63.6% (HIV-infected), 64.2% (uninfected). Conclusion LC16m8’s effectiveness in mpox prevention remains inconclusive. Yet, its use in well-controlled HIV-infected and -uninfected individuals showed no significant safety concerns, suggesting potential for targeted vaccination strategies in at-risk groups. Disclosures All Authors: No reported disclosures

Monkeypox: A resurfacing threat and global public health challenge in India

The global monkeypox outbreak presents a significant public health challenge, particularly in India, due to its rapid spread and the complexities of controlling transmission. This commentary discusses the epidemiological trends, transmission dynamics, and the challenges faced in managing the outbreak. Adopting a multidisciplinary approach, it reviews available data and literature on the spread and control of monkeypox, examining current surveillance systems, public health preparedness measures, and strategies employed to contain the disease. The review indicates that while efforts are underway to manage the outbreak, significant gaps remain in global surveillance and preparedness. The lack of targeted vaccination strategies and inconsistent public health responses exacerbate the difficulty of controlling monkeypox. Additionally, notable gaps persist in understanding its full transmission dynamics. The commentary calls for enhanced surveillance systems, improved public health preparedness, and the development of targeted vaccination strategies to mitigate the spread of monkeypox. It also emphasizes the need for a coordinated global response to emerging infectious diseases and proposes a more integrated, multidisciplinary approach to strengthening global health collaborations.

Comorbidities Associated With Different Degrees of Severity in Children and Young People Hospitalized With Acute COVID-19.

In this prospective cohort study with 2326 hospitalized children and young people with coronavirus disease 2019 in Spain and Colombia, 36.4% had comorbidities. Asthma, recurrent wheezing, chronic neurological, cardiac and pulmonary diseases significantly increased the risk of severe outcomes such as death, mechanical ventilation and intensive care unit admission. The incremental risk with additional comorbidities underscores the importance of targeted vaccination strategies for vulnerable children and young people populations.

Skin as outermost immune organ of vertebrates that elicits robust early immune responses after immunization with glycoprotein of spring viraemia of carp virus.

As the outermost immune organ in vertebrates, the skin serves as the primary interface with the external environment and plays a crucial role in initiating the early immune response. The skin contains a variety of immune cells that induce mucosal and systemic immune responses, rendering it a prime target for vaccination strategies. Insight into the mechanisms through which vaccination triggers early immune responses is paramount for advancing animal and human health, yet our current understanding remains limited. Given its significance in vertebrate evolution, teleost fish emerges as an excellent model for investigating the early immune response of skin. In this study, we demonstrate that significant quantities of vaccine can be absorbed by the skin and transported to the body through dermis and muscle metabolism by immerses immune zebrafish with glycoprotein of spring viraemia of carp virus. Immersion immunization can elicit robust and enduring immune protection, with the skin triggering a potent immune response early in the immunization process. Analysis of the skin transcriptome revealed the involvement of numerous immune-related genes in the immersion immune response, with indications that HSP70 and MAPK signals might play pivotal roles in the immune process induced by glycoprotein. Co-immunoprecipitation and cell co-localization studies confirmed the interaction between glycoprotein and HSP70. Subsequent research demonstrated that overexpression or inhibition of HSP70 could respectively enhance or impede the expression of JNK and related proteins. However, the survival rate and immune response of HSP70 inhibited zebrafish with glycoprotein treatment were significantly reduced. These findings propose that the interaction between glycoprotein and HSP70 may activate JNK, thereby modulating mucosal and systemic immune responses induced by glycoprotein. This investigation offers novel insights and a foundational understanding of early skin immune reactions.

Tetanus Vaccination in Agricultural Workers: A Retrospective Study on Seroprevalence over 10 Years.

Tetanus is a serious, non-contagious infection caused by Clostridium tetani, which remains a global health threat despite the availability of an effective vaccine. The current state of immunization for agricultural workers in Italy reveals significant disparities, reflecting a non-homogeneous distribution of vaccination coverage across regions and subgroups. The aim of the study was to investigate the prevalence of tetanus antibodies in a cohort of agricultural workers in Eastern Sicily in order to evaluate possible public health strategies for improving vaccination coverage. This observational retrospective study assessed tetanus immunization coverage in agricultural workers in Eastern Sicily during the period from 2012-2022. A total of 1143 workers participated, of which 71% (n = 871) had protective tetanus antitoxin levels. Of the 835 vaccinated workers, 9% were not immune, while 19% of those who were not vaccinated or did not recall their vaccination history were immune. Significant gaps in vaccination were noted, particularly among non-European workers, with only 23% vaccinated compared to 89% of European workers. Additionally, vaccination rates were higher in those born after 1963, when vaccination became mandatory. The results underscore the need for targeted vaccination strategies, especially for older and migrant workers, as well as the importance of workplace immunization programs led by occupational physicians. Improving vaccination coverage among agricultural workers is essential for preventing tetanus infections in high-risk agricultural populations.

Mass cytometry reveals cellular correlates of immune response heterogeneity to SARS-CoV-2 vaccination in the elderly

Heterogeneity in vaccine response, particularly in vulnerable populations like the elderly, represents a significant public health challenge. We conducted an in-depth examination of immune cell profiles before and after SARS-CoV-2 vaccination utilizing mass cytometry in a cohort of healthy Norwegian seniors (65–80 years). We have demonstrated that higher pre-vaccination frequencies of CD27+IgD- class-switched memory B cells and subsets of CD27-CD24+CD38+ transitional B cells were associated with a robust vaccine response. Post-vaccination, high responders exhibited increased frequencies of IFN-γ+CD4+ T cells with antigen recall and a concurrent decrease in CCR6(+) TH cell subset frequencies compared to low responders. The presence of a γδ T cell subset displaying polyfunctional cytokine responses was also associated with better vaccine response in the elderly. This in-depth profiling sheds light on inherent differences in immune cell frequencies and functions that may offer insights for targeted vaccination strategies in older populations.

Severe Acute Respiratory Infection (SARI) due to Influenza in Post-COVID Resurgence: Disproportionate Impact on Older Māori and Pacific Peoples.

Influenza reemerged after a 2020-2021 hiatus in 2022, but understanding the resurgence needs pre-COVID era surveillance. We compared age- and ethnicity-specific incidence of severe acute respiratory infection (SARI) from a hospital network in Auckland, New Zealand, in 2022 against a baseline, 2012-2019. Annual and monthly influenza SARI incidence per 1000 persons by age and ethnic group between 2012 and 2022 was calculated using resident population as the denominator. The hospitals capture most severe illness of the resident population. Influenza SARI incidence was highest among <1 year olds (2.62; 95% CI: 1.84-3.61) during 2012-2019, lowest at 6-14 years, and did not significantly increase until 50-64 years (0.35; 95% CI: 0.27-0.45), reaching 1.19 (95% CI: 0.57-1.55) in those ≥75 years. In all age groups, incidence was at least threefold higher in Māori and Pacific Peoples. No influenza SARI was identified in 2020-2021. In 2022, despite an early peak, annual incidence (<65 years) was lower than baseline in all ethnic groups, but incidence (≥65 years) in Māori (2.06; 95% CI: 1.22-3.26) and Pacific (3.94; 95% CI: 2.97-5.13) peoples was higher in 2022 than most baseline years, whereas incidence in NMNP (0.22; 95% CI: 0.14-0.32) was lower than any baseline year. After no influenza 2020-2021, Auckland had an early, high, narrow peak in 2022. Stratification by age and ethnicity revealed striking discrepancies in incidence among Māori and Pacific adults over 65 years compared with NMNP adults, with implications for targeted vaccination strategies.

Conformational variability in the D2 loop of Plasmodium Apical Membrane antigen 1

Apical Membrane Antigen 1 (AMA1) plays a vital role in the invasion of the host erythrocyte by the malaria parasite, Plasmodium. It is thus an important target for vaccine and anti-malaria therapeutic strategies that block the invasion process. AMA1, present on the surface of the parasite, interacts with RON2, a component of the parasite’s rhoptry neck (RON) protein complex, which is transferred to the erythrocyte membrane during invasion. The D2 loop of AMA1 plays an essential role in invasion as it partially covers the RON2-binding site and must therefore be displaced for invasion to proceed. Several structural studies have shown that the D2 loop is very mobile, a property that is probably important for the function of AMA1. Here we present three crystal structures of AMA1 from P. falciparum (strains 3D7 and FVO) and P. vivax (strain Sal1), in which the D2 loop could be largely traced in the electron density maps. The D2 loop of PfAMA1-FVO and PvAMA1 (as a complex with a monoclonal antibody Fab) has a conformation previously noted in the P. knowlesi AMA1 structure. The D2 loop of PfAMA1-3D7, however, reveals a novel conformation. We analyse the conformational variability of the D2 loop in these structures, together with those previously reported. Three different conformations can be distinguished, all of which are highly helical and show some similarity in their secondary structure organisation. We discuss the significance of these observations in the light of the flexible nature of the D2 loop and its role in AMA1 function.

Multiple vaccine comparison in the same adults reveals vaccine-specific and age-related humoral response patterns: an open phase IV trial

Vaccine responsiveness is often reduced in older adults. Yet, our lack of understanding of low vaccine responsiveness hampers the development of effective vaccination strategies to reduce the impact of infectious diseases in the ageing population. Young-adult (25–49 y), middle-aged (50-64 y) and older-adult ( ≥ 65 y) participants of the VITAL clinical trials (n = 315, age-range: 28-98 y), were vaccinated with an annual (2019–2020) quadrivalent influenza (QIV) booster vaccine, followed by a primary 13-valent pneumococcal-conjugate (PCV13) vaccine (summer/autumn 2020) and a primary series of two SARS-CoV-2 mRNA-1273 vaccines (spring 2021). This unique setup allowed investigation of humoral responsiveness towards multiple vaccines within the same individuals over the adult age-range. Booster QIV vaccination induced comparable H3N2 hemagglutination inhibition (HI) titers in all age groups, whereas primary PCV13 and mRNA-1273 vaccination induced lower antibody concentrations in older as compared to younger adults (primary endpoint). The persistence of humoral responses, towards the 6 months timepoint, was shorter in older adults for all vaccines (secondary endpoint). Interestingly, highly variable vaccine responder profiles overarching multiple vaccines were observed. Yet, approximately 10% of participants, mainly comprising of older male adults, were classified as low responders to multiple vaccines. This study aids the identification of risk groups for low vaccine responsiveness and hence supports targeted vaccination strategies. Trial number: NL69701.041.19, EudraCT: 2019-000836-24.

Unveiling the dynamics of respiratory infections revealed by multiplex PCR testing during the COVID-19 pandemic in Taiwan, 2020–2023

BackgroundThe emergence of SARS-CoV-2 in late 2019 sparked the global COVID-19 pandemic, leading to varied vaccine policies worldwide. The evolving patterns of respiratory pathogens, aside from SARS-CoV-2, during the pandemic have had a significant impact on the development of vaccine strategies. MethodsThis study explores the landscape of respiratory pathogens, encompassing SARS-CoV-2, respiratory syncytial virus (RSV), and influenza viruses, through a retrospective analysis of data obtained from the BioFire Respiratory Panel 2.1 (RP 2.1) at China Medical University Hospital (Taichung, Taiwan) spanning from January 2020 to November 2023. ResultsAmong the 7950 respiratory samples studied, pediatric cases exhibited higher positivity (64.9%, 2488/3835) and mixed detection rates (43.8%, 1090/2488) than adults. Annual mixed detection rates increased (27.9–48%). Prevalence analysis revealed diverse patterns across age groups, with higher rates in pediatrics. Notably, human rhinovirus/enterovirus predominated (48.1%). Mixed detection illustrated viral co-detections, notably with parainfluenza viruses and adenovirus. Government policies and pandemic dynamics influenced infection patterns, with RSV resurgence after May 2022. Age-specific RSV detection demonstrated a shift, influencing vaccine considerations. Amid global vaccine initiatives, RSV's increasing trend in adults warrants attention. ConclusionsThis comprehensive analysis emphasizes the importance of multiplex PCR testing in shaping targeted vaccination strategies during evolving respiratory pathogen landscapes.

A targeted vaccination strategy based on dynamic community detection for epidemic networks

A targeted vaccination strategy based on dynamic community detection for epidemic networks

Accelerating COVID-19 Vaccination Among People Living With HIV and Health Care Workers in Tanzania: A Case Study.

There is limited evidence on COVID-19 vaccination uptake among people living with HIV (PLHIV) and health care workers (HCWs), with the current evidence concentrated in high-income countries. There is also limited documentation in the published literature regarding the feasibility and lessons from implementing targeted vaccination strategies to reach PLHIV and HCWs in low- and middle-income countries. We designed and implemented multifaceted strategies to scale up targeted COVID-19 vaccination among PLHIV and HCWs in 11 administrative regions on the mainland of Tanzania plus Zanzibar. An initial 6-week intensification strategy was implemented using a diverse partnership model comprising key stakeholders at the national- and subnational levels. A layered package of strategies included expanding the number of certified vaccinators, creating vaccination points within HIV clinics, engaging HCWs to address their concerns, and building the capacity of HCWs as "champions" to promote and facilitate vaccination. We then closely monitored COVID-19 vaccination uptake in 562 high-volume HIV clinics. Between September 2021 and September 2022, the proportion of fully vaccinated adult PLHIV increased from <1% to 97% and fully vaccinated HCWs increased from 23% to 80%. Our intra-action review highlighted the importance of leveraging a strong foundation of existing partnerships and platforms, integrating COVID-19 vaccination points within HIV clinics, and refining strategies to increase vaccination demand while ensuring continuity of vaccine supply to meet the increased demand. Lessons from Tanzania can inform targeted vaccination of vulnerable groups in future health emergencies.

Influenza Vaccination Coverage among People with Self-Reported Cardiovascular Diseases-Findings from the Hungarian Implementation of the European Health Interview Survey.

Worldwide, cardiovascular diseases are the leading cause of mortality. This has significant implications for public health. Influenza, a common infectious disease, poses an increased risk for individuals with chronic conditions, such as cardiovascular diseases. However, little is known about influenza vaccination coverage in this group. This study utilized data from the Hungarian implementation of the European Health Interview Survey to assess influenza vaccination coverage and its determinants among cardiovascular respondents from 2009 to 2019. The findings reveal a downward trend in the vaccination rates over the years (from 24% to 21%), despite the availability of free vaccination in Hungary for this high-risk population. The main factors influencing low influenza vaccine uptake were identified, as follows: young age, a lower level of education, good self-perceived health status, smoking, a lower frequency of medical visits, and not suffering from respiratory diseases. Addressing these disparities necessitates targeted vaccination strategies supported by enhanced education, better access to healthcare services, and the promotion of preventive healthcare measures. Improving vaccination coverage among patients with cardiovascular diseases is imperative for reducing influenza-related morbidity and mortality. This highlights the importance of comprehensive public health interventions and healthcare provider engagement in promoting vaccination among groups at increased risk.

Effectiveness of Sinopharm's BBIBP-CorV Booster Vaccination against COVID-19-Related Severe and Critical Cases and Deaths in Morocco during the Omicron Wave.

This study investigates the effectiveness of the 1st booster dose against COVID-19 severe and critical hospitalizations and deaths occurring due to the Omicron wave in Morocco. This study uses nationally representative data on COVID-19 from 15 December 2021 to 31 January 2022. The aim is to investigate the effectiveness of the inactivated COVID-19 vaccine BBIBP-CorV (Sinopharm) 1st booster dose against the Omicron wave in Morocco using real-world data established from nationally representative statistics on COVID-19 cases, deaths and vaccinations. The screening method was used to estimate vaccine effectiveness against COVID-19 severe or critical hospitalization and COVID-19-related deaths. The data were grouped by, age subgroup, sex, week, and geographical area and were analyzed using binary logistic regression with an offset for vaccine coverage. The overall BBIBP-CorV VE estimate is 89% (95% CI 85 to 92) effective in curbing COVID-19 deaths, and 81% (95% CI 78 to 84 in curbing COVID-19 severe/critical hospitalizations. Death-related VE estimate was 86% (95% CI 81 to 90) for patients aged ≥65 years, 96% (95% CI 90 to 98) for those aged <65 years, 95% (95% CI 88 to 98) in no-risk factor patients, 91% (95% CI 85 to 94) with 1 risk factor, 90% (95% CI 83 to 95) with 2 risk factors, and 72% (95% CI 52 to 84) in patients with 3 risk factors and more. Severe/critical hospitalization VE estimate was 78% (95% CI 74 to 82) for patients aged ≥65 years, 87% (95% CI 82 to 90) for those aged <65 years, 86% (95% CI 80 to 90) in no-risk factor patients, 80% (95% CI 73 to 84) with 1 risk factor, 80% (95% CI 70 to 85) with 2 risk factors, and 80% (95% CI 68 to 86) in patients with 3 risk factors and more. BBIBP-CorV boosters are effective in increasing protection against the Omicron variant-related COVID-19 deaths and severe/critical hospitalizations. The protection is reduced with older age and higher risk factors. These findings emphasize the importance of targeted vaccination strategies for different demographic groups and underscore the protective benefits of the first booster BBIBP-CorV vaccine.

Acceptability, cost-effectiveness, and capacity of a facility-based seasonal influenza vaccination among high-risk groups: a study protocol in selected tertiary care hospitals of Bangladesh

BackgroundIn Bangladesh, seasonal influenza imposes considerable disease and economic burden, especially for those at high-risk of severe disease. The most successful approach for influenza prevention is the administration of a vaccine. Many poor and middle-income nations, including Bangladesh, do not have a national strategy or program in place for seasonal influenza vaccines, despite the World Health Organization’s (WHO) advice to prioritize high-risk populations. Additionally, there is a scarcity of substantial data on the cost-effectiveness of seasonal influenza vaccination in these countries. The aim of our study is to determine acceptability, health beliefs, barriers, and intention of receiving influenza vaccine among high-risk populations, assess the cost-effectiveness of implementing a facility-based seasonal influenza vaccination programme, and investigate the required capacity for a potential seasonal influenza vaccination programme.MethodsWe will undertake this study following STROBE guidelines. We will conduct the study in inpatient and outpatient departments of three selected tertiary-level hospitals leveraging the ongoing hospital-based influenza surveillance (HBIS) platform. The study population will include the WHO-defined four high-risk groups excluding healthcare workers: children six months to eight years, pregnant women, elderly ≥ 60 years, and adults with chronic diseases. We will collect quantitative data on participants’ acceptability, health beliefs, barriers, and vaccination intentions using the health belief model (HBM) from patients meeting the criteria for high-risk populations attending two public tertiary-level hospitals. In one of the two public tertiary-level hospitals, we will arrange an influenza vaccination campaign before the influenza season, where the vaccine will be offered free of cost to high-risk patients, and in the second hospital, vaccination will not be offered. Both the vaccinated and unvaccinated participants will then be followed-up once a month for one year to record any influenza-like illness, hospitalization, and death. Additional data for objective two will be collected from patients with symptoms of influenza-like illness (ILI) and severe acute respiratory infection (SARI) at one public and one private hospital to determine both direct and indirect costs associated with influenza illness. We will estimate the required number of influenza vaccines, safe injections, and total storage volume utilizing secondary data. We will use a deterministic Markov decision-analytic model to estimate the cost-effectiveness of facility-based influenza vaccination in Bangladesh.DiscussionThe results of this study will enable the National Immunization Technical Advisory Group and the Ministry of Health & Family Welfare of Bangladesh to decide what steps to take to develop and implement an influenza vaccination strategy targeting high-risk populations.Trial registrationThe Clinicaltrials.gov registration number is NCT05996549. The registration for the protocol version 2.0 took place in August 2023, with the initial participant being enrolled in March 2022.

Having a real say: findings from first nations community panels on pandemic influenza vaccine distribution

BackgroundRecent deliberations by Australian public health researchers and practitioners produced an ethical framework of how decisions should be made to distribute pandemic influenza vaccine. The outcome of the deliberations was that the population should be considered in two categories, Level 1 and Level 2, with Level 1 groups being offered access to the pandemic influenza vaccine before other groups. However, the public health researchers and practitioners recognised the importance of making space for public opinion and sought to understand citizens values and preferences, especially First Nations peoples.MethodsWe conducted First Nations Community Panels in two Australian locations in 2019 to assess First Nations people’s informed views through a deliberative process on pandemic influenza vaccination distribution strategies. Panels were asked to make decisions on priority levels, coverage and vaccine doses.ResultsTwo panels were conducted with eighteen First Nations participants from a range of ages who were purposively recruited through local community networks. Panels heard presentations from public health experts, cross-examined expert presenters and deliberated on the issues. Both panels agreed that First Nations peoples be assigned Level 1 priority, be offered pandemic influenza vaccination before other groups, and be offered two doses of vaccine. Reasons for this decision included First Nations people’s lives, culture and families are important; are at-risk of severe health outcomes; and experience barriers and challenges to accessing safe, quality and culturally appropriate healthcare. We found that communication strategies, utilising and upskilling the First Nations health workforce, and targeted vaccination strategies are important elements in pandemic preparedness and response with First Nations peoples.ConclusionsFirst Nations Community Panels supported prioritising First Nations peoples for pandemic influenza vaccination distribution and offering greater protection by using a two-dose full course to fewer people if there are initial supply limitations, instead of one dose to more people, during the initial phase of the vaccine roll out. The methodology and findings can help inform efforts in planning for future pandemic vaccination strategies for First Nations peoples in Australia.

Mandatory Vaccination against COVID-19: Qualitative Analysis of Responses to Open-Ended Questions

The mandatory COVID-19 vaccination has been suggested as a strategy to increase vaccination uptake; however, there are doubts about its legitimacy as a measure. This study aimed to explore in depth the opinions of the Cypriot population regarding mandatory vaccination against COVID-19. Qualitative analysis of responses to an open-ended question was included as part of an anonymous, online, cross-sectional survey of the general population of Cyprus. A thematic analysis was performed by reading the responses and developing a coding frame. Descriptive analysis was performed on the sociodemographic and COVID-19-vaccine-related information. A total of 311 participants responded to the open-ended question, and the thematic analysis yielded two main themes: “Vaccination Perceptions and Challenges” and “Mandatory Vaccination Policies and Societal Impact.” Within these themes, participants expressed diverse opinions on universal and targeted mandatory vaccination, highlighting concerns about insufficient research, gaps in communication, and potential side effects. Views also varied on topics such as protective measures, interdisciplinary collaboration, vaccine side effects, human rights, and societal divisions. Criticisms encompassed political motives, skepticism towards the pandemic, and considerations of individual freedoms. In summary, the findings highlighted the intricate and varied perspectives surrounding the issue of mandatory COVID-19 vaccination, which can be valuable for policymakers and public health officials in designing targeted vaccination strategies. To optimize vaccination programs, policymakers and public health officials should prioritize trust, communication, and individual autonomy.

COVID’s First and Second Waves in India: Lessons and Policy Implications

In this article, we argue that in a supply-deficient situation, a vaccination strategy that makes use of an analysis of the different stages of the COVID waves and the pattern of their geographical spread can prove to be far more effective than the current non-transparent mechanism of inter-state allocation of the vaccines. We divide the spread of the COVID waves into three stages: (a) seeding stage, (b) explosion stage and (c) subsiding and diffusion stages. In the seeding stage, two critical determinants of seeding the virus into the population are (a) the inter-state pattern of arrival of international passengers and (b) the inter-state pattern of the continuing active COVID-affected population from the previous wave. The explosion stage induces a policy response in the form of lockdowns which is followed by the wave starting to subside. But the lockdown also results in the migration of labour out of the state into the rural and less populated areas, leading to the diffusion stage. We advocate a vaccination strategy targeting universal coverage with strategic sequencing in which prioritisation is given to ‘saturation vaccination’ of high-density and high COVID-intensity urban areas. This would not only minimise the economic costs in terms of duration and spread of lockdowns but also the pressures on the inadequate health infrastructure in terms of availability of hospital beds, ambulances, oxygen and drugs. This strategy may be implemented in curbing the COVID’s subsequent waves which may hit India while its population is still only partially vaccinated.

Differential T-cell and antibody responses induced by mRNA versus adenoviral vectored COVID-19 vaccines in patients with immunodeficiencies.

Immunodeficient patients (IDPs) are at higher risk of contracting severe coronavirus disease 2019 (COVID-19). Targeted vaccination strategies have been implemented to enhance vaccine-induced protection. In this population, however, clinical effectiveness is variable and the duration of protection unknown. We sought to better understand the cellular and humoral immune responses to mRNA and adenoviral vectored COVID-19 vaccines in patients with immunodeficiency. Immune responses to severe acute respiratory syndrome coronavirus 2 spike were assessed after 2 doses of homologous ChAdOx1-nCoV-19 or BNT162b2 vaccines in 112 infection-naive IDPs and 131 healthy health care workers as controls. Predictors of vaccine responsiveness were investigated. Immune responses to vaccination were low, and virus neutralization by antibody was not detected despite high titer binding responses in many IDPs. In those exhibiting response, the frequency of specific T-cell responses in IDPs was similar to controls, while antibody responses were lower. Sustained vaccine specific differences were identified: T-cell responses were greater in ChAdOx1-nCoV-19- compared to BNT162b2-immunized IDPs, and antibody binding and neutralization were greater in all cohorts immunized with BNT162b2. The positive correlation between T-cell and antibody responses was weak and increased with subsequent vaccination. Immunodeficient patients have impaired immune responses to mRNA and viral vector COVID-19 vaccines that appear to be influenced by vaccine formulation. Understanding the relative roles of T-cell- and antibody-mediated protection as well as the potential of heterologous prime and boost immunization protocols is needed to optimize the vaccination approach in these high-risk groups.