Trust and vaccination intentions: Evidence from Lithuania during the COVID-19 pandemic.

In this paper, we study the relationship between trust and COVID-19 vaccination intentions. Vaccinating a large share of the population is essential for containing the COVID-19 pandemic. However, many individuals refuse to get vaccinated, which might be related to a lack of trust. Using unique survey data from Lithuania during the COVID-19 pandemic, we show that trust in government authorities, science, and pharmaceutical companies are important predictors of individual vaccination intentions. We do not find evidence that trust in strangers, the healthcare system, or the media predict intentions to get vaccinated against COVID-19.

Reducing the risk of transfusion-transmitted infectious disease markers in blood and blood component donations: Movement from remunerated to voluntary, non-remunerated donations in Lithuania from 2013 to 2020.

Lithuania has a long history of remunerated donations. The first steps towards voluntary, non-remunerated blood and blood component donations started in 2004. Lithuania achieved 99.98% voluntary non-remunerated donations (VNRDs) in 2020. This study aimed to assess the risk of transfusion-transmitted infectious (TTI) disease markers for remunerated donations in comparison with VNRDs in Lithuania from 2013 to 2020. Data were obtained from the Lithuanian Blood Donor Register. The prevalence was calculated as the rate between the number of confirmed positive results for all TTI disease markers (serological anti-HCV, HBsAg, Ag/anti-HIV 1 and 2, and syphilis, and/or HCV, HBV, and HIV-1 NAT) per 100 donations. The relative risk of infectious disease markers for remunerated donations was then estimated. In total, 796310 donations were made. Altogether, 2743 donations were positive for TTI markers as follows: HCV, 1318; HBV, 768; syphilis, 583; and HIV 1 and 2, 74. The prevalence of confirmed TTI markers were 2.86, 0.97, 0.18, and 0.04 per 100 first-time remunerated donations, first-time VNRDs, repeat remunerated donations, and repeat VNRDs, respectively. Remunerated first-time and repeat donations had a statistically higher prevalence of TTI disease markers than VNRDs. First-time and repeat remunerated donations had statistically significantly higher relative risks of confirmed TTI disease markers than VNRD. In conclusion, the risks of TTI disease markers for remunerated first-time and repeat blood and its component donations are significantly higher than those for VNRDs.

The perceptions of Lithuanian hunters towards African swine fever using a participatory approach.

BACKGROUND: African swine fever (ASF) has been present in Lithuania since 2014. The disease affects mainly the wild boar population. Thus, hunters play a key role in the performance of disease surveillance and control measures. We used participatory methods to gain insight into the knowledge of hunters and to include their perceptions in the design and the implementation of surveillance and control measures to increase their effectiveness. RESULTS: The willingness and the interest of hunters to participate was high, but only eight focus group meetings with 33 hunters could be held due to the COVID-19 pandemic. The overall knowledge of Lithuanian hunters regarding ASF, investigated by semi-structured interviews, was sufficient to understand their part in ASF control and surveillance. However, their knowledge did not necessarily lead to an increased acceptance of some ASF control measures, like the targeted hunting of female wild boar. Participating hunters showed a good understanding of the processes of the surveillance system. Their trust in the performance within this system was highest towards the hunters themselves, thus emphasizing the importance of acknowledging their role in the system. Hunters refused measures including the reduction of hunting activities. They feared a complete elimination of the wild boar population, which in turn demonstrates the necessity to increase professional information exchange. CONCLUSIONS: The perceptions of Lithuanian hunters regarding ASF surveillance and control in wild boar resembled those obtained in neighboring countries. It is imperative to communicate the results with decision-makers, to consider the views of hunters, when designing or adapting measures to control ASF in wild boar and to communicate with hunters on these measures and their justification.

An analysis of the causes of exhaustion among physicians working in family physician teams during the COVID-19 pandemic in Lithuania.

BACKGROUND: The COVID-19 pandemic had a severe impact on public life around the world, influencing medicine and health, the economy, employment, science, and education. Health care specialists are key workers who faced extreme challenges posed by the pandemic, including threats to their own lives due to the rapid spread of the virus, a huge increase in workload, and professional burnout syndrome. Analysis of the factors that physicians found most exhausting during the pandemic could lay the groundwork for the effective management of future crises. OBJECTIVE: To identify the factors that physicians working in family physician (family and internal medicine) teams found most exhausting during the COVID-19 pandemic in Lithuania and assess their causes. METHODS: An anonymous survey of physicians (n = 191) working in family physician teams was carried out from 21 June 2021 to 17 September 2021. Physicians signed an informed consent form prior to completion of the questionnaire. Mixed data analysis was performed, consisting of statistical analysis using the SPSS 27 software and a qualitative causal analysis. RESULTS: During the pandemic, physicians were most exhausted by: chaotic vaccination priorities (44.5%); unsatisfied patients (52.4%); constantly changing legislation (71.7%); the large workload (75.9%); and the malfunctioning of online systems (81.2%). CONCLUSIONS: Physicians in family physician teams indicated the following aspects that require improvement: service provision; effective work organization for physicians; and the satisfaction of patients with decisions made during the pandemic.

The Psychological Well-Being and Civic Engagement of Polish, Croatian and Lithuanian Academic Students during COVID-19 Outbreak.

The aim of this research was to recognize the relationship between well-being and civic engagement under the difficult circumstances of the COVID-19 pandemic amongst students from Poland, Lithuania and Croatia. Overall, 1362 academic students (Poland, n = 596, Croatia, n = 386, and Lithuania, n = 379) participated in the study. Mean rank differences in civic engagement level (overall CE) were analysed by levels of psychological well-being (overall PWB and its subscales) using the Kruskal-Wallis test (one-way ANOVA on ranks). We conducted post hoc analysis with Bonferroni tests to measure the significance of differences in CE between the detailed levels of PWB. To avoid biases due to interaction effects between dependent variables, the analysis of mean ranks was followed by a binomial logistic regression analysis model and subgroups analysis (by gender and by country). Results obtained showed that students with higher levels of psychological well-being have higher levels of civic engagement. The differences in the CE level are most pronounced in relation to the dimension of a PWB, such as "positive relations with others", followed by "personal growth", "autonomy", and "self-acceptance". In a crisis, such as a pandemic, it is worth encouraging students to take targeted actions, as well as to create actions referring to personal development and relationships. There were no differences in the direction and shape of the associations between psychological well-being and civic engagement with respect to the country and the gender of the participants, which leads us to draw conclusions pointing to the globalised nature of student experience during the pandemic in this part of Europe.

Mental Health and Physical Activity of Female Higher Education Students during the COVID-19 Pandemic: A Comparative Cross-Sectional Study from Lithuania.

During emerging adulthood (EA), higher education medical students undergo a higher risk of anxiety and depression compared to the general population. The aim of this comparative cross-sectional study was to compare the proportions of three mental disorders, namely anxiety, depression and somatisation in terms of their symptoms and self-reported physical activity (PA) levels across the cohorts of biomedical and non-biomedical female students as well as to assess the association between the mental health outcomes and PA use. Between September 2021 and January 2022, a total of 1231 female higher education students aged between 18 and 29 years old were recruited for the study. Severe symptoms of anxiety and depression, as well as unexplained somatic complaints, were suffered by 51.9%, 11% and 23% of female students, respectively. Non-biomedical female students, compared to medicine and health sciences students, were more vulnerable due to the increased prevalence of negative mental health outcomes. The relationship between increased sports activity as a potential trigger for mental well-being and decreased severity of depressive symptoms was identified in the cohorts of both biomedical (adjusted odd ratio (ORadj) 0.4; 95% confidence interval (CI): 0.1-1.0) and non-biomedical (ORadj 0.4; 95% CI: 0.2-0.9) female students. The current research highlights the importance of increasing sports activity by involving students in regular physical exercise of specific types for decreasing the severity of depressive symptoms in student-aged female populations.

COVID-19 Pandemic and Consumption of Dietary Supplements among Adult Residents of Lithuania.

In the light of the changing pattern of the consumption of dietary supplements among adults in other countries during the COVID-19 pandemic, we aim to assess the prevalence of the consumption of dietary supplements with respect to the purpose of consumption and sociodemographic factors among adults in Lithuania. This study included two samples of adults from Lithuania: 870 in 2019 and 1600 in 2021. Anonymous original questionnaires were used to collect the data about the consumption of dietary supplements before and during the pandemic. The consumption of dietary supplements was prevalent among 67.2% and 78.1% of the samples, respectively. Although the majority (73.7%) of the respondents indicated that the pandemic had no effect on their use of dietary supplements, every fourth respondent's (24.6%) consumption increased. In 2021, the consumption was more prevalent among females, respondents with university education, urban citizens, employed respondents, respondents without children, with higher income, and those who knew a person with COVID-19 (p < 0.05). During the pandemic, the strengthening of the immune system and the body were the leading reasons for consumption (49.0% and 43.5%, respectively). The consumption of dietary supplements appropriate for these purposes increased among 63.3% and 66.9% of respondents, respectively. To conclude, the consumption of dietary supplements among adults in Lithuania increased during the COVID-19 pandemic.

Herbal Medicine Uses for Respiratory System Disorders and Possible Trends in New Herbal Medicinal Recipes during COVID-19 in Pasvalys District, Lithuania.

Despite some preliminary studies of the available herbal medicine preparations and their curative effects on COVID-19, experts still fear that unproper use of such homemade medicines could do more harm than good to people relying on unproven alternatives of questionable efficacy. The main purpose of this study was to evaluate the safety of herbal medicines used for respiratory system disorders in the Pasvalys district during the COVID-19 pandemic in Lithuania. An archival source was also studied, looking for possible recipes for the treatment and prevention of respiratory diseases in Lithuanian traditional medicine, emphasizing the safety guidelines. The survey was conducted using the deep interview method. The respondents mentioned 60 species of medicinal plants from 29 different families used for the treatment and prevention of respiratory system disorders (for cough mostly, 51.70% of all indications). Twenty eight out of 60 plant species were not included in the European Medicines Agency monographs and only 50% of all included species were used as indicated by the European Medicines Agency for respiratory system disorders. The trends in the ethnopharmacological choices of modern consumers and the analysis of archival sources can be a great source of ideas for new herbal-based pharmaceutical preparations for COVID-19 symptoms in Lithuania considering the safety recommendations.

Ethnopharmacology for Skin Diseases and Cosmetics during the COVID-19 Pandemic in Lithuania.

The documentation of ethnopharmaceutical knowledge has always been important for the preservation of countries' cultural, social, and economic identity. The COVID-19 pandemic with the collapse of healthcare, which has left the individual health to self-care, has also forced us to look back at ethnopharmacology from a practical point of view. This is the first study in Lithuania, dedicated entirely to ethnopharmaceuticals used for skin diseases and cosmetics, and the first study to analyse ethnopharmacology as a Lithuanian phenomenon during the ongoing COVID-19 pandemic. The main purpose of this study was to collect and evaluate ethnopharmaceutical knowledge regarding skin diseases and cosmetics in Siauliai District, Lithuania during the COVID-19 pandemic from July 2020 to October 2021. This study surveyed 50 respondents; the survey was conducted using the deep interview method. The respondents mentioned 67 species of medicinal plants from 37 different families used for skin diseases (64.18%), cosmetics (13.44%) and cosmeceuticals (22.38%). Of the 67 plant species, 43 (64%) were not included in the European Medicines Agency monographs and only 14 species (21%) of all included species were used with European Medicines Agency approved medical indications for skin diseases. In terms of public health, the safety of "self-treatment" and recovery rituals for skin diseases are no less important than ethnopharmacological knowledge and its application, this being especially relevant during the COVID-19 pandemic.

Examining the Associations between Adverse Childhood Experiences, Health Risk Behaviours, and Psychological Well-Being in a Convenience Sample of Lithuanian University Students.

This study examines the associations between adverse childhood experiences (ACEs), health risk behaviours, and psychological well-being among Lithuanian university students. A cross-sectional survey was carried out with a convenience sample of 393 students (80.7% females and 19.3% males) recruited from mostly undergraduate courses (96.4%) in Lithuanian universities. Participants, aged 18-25 years (21.07 ± 1.53), completed a web-based survey in which they were asked to retrospectively self-report on ACEs while answering questions on health risk behaviours (e.g., smoking, substance use, riding a car with a drunk driver) and psychological well-being. Only 8.7% of the study sample experienced no ACEs, and almost half of the sample (48.9%) experienced ≥4 ACEs. Findings from adjusted models showed that, compared with students with no ACEs, those who experienced ≥4 ACEs had higher odds of lifetime illicit drug use (AOR = 2.73, p < 0.05), riding with a drunk driver (AOR = 2.44, p < 0.05), suicidal ideation before age 18 (AOR = 28.49, p < 0.01) and in the past 12 months (AOR = 5.39, p < 0.01). An increased number of ACEs was also associated with lower psychological well-being (B = -3.94, p < 0.001). Findings from this study have implications for mental health professionals as well as university administrators, as students with a higher number of traumatic experiences may require greater levels of support and services.

The Predictors of Psychological Well-Being in Lithuanian Adolescents after the Second Prolonged Lockdown Due to COVID-19 Pandemic.

Recent research highlights the impact of prolonged pandemics and lockdown on the mental health of youngsters. The second wave of COVID-19 brought an increase in mental health problems among young people. Therefore, this study aims to analyze the main factors arising from intra-individual, inter-individual, and environmental contexts that predict good psychological well-being in a group of adolescents after a second prolonged period of social restrictions and distance education. The study included 1483 school students from 11 to 19 years old. The survey assessed self-reported students' psychological well-being (WHO-5 index), physical activity, sedentary behavior, school social capital, communication with peers and relationships with parents, existing emotional and behavioral problems. The results indicated that 58% of adolescents were of good psychological well-being in spring 2021, after half a year in lockdown. Almost 19% of adolescents had depression risk. The study revealed that during a period of prolonged isolation, male gender, better relationships between young people and their parents, the absence of serious emotional and behavioral problems, less sedentary behavior, and higher school social capital were found to be significant factors predicting adolescents' psychological well-being. Lower physical activity is an important contributor to students' poor well-being. Finally, the lack of face-to-face communication with peers was revealed as a specific factor in predicting adolescents with depression risk.

Social Attitude to COVID-19 and Influenza Vaccinations after the Influenza Vaccination Season and between the Second and Third COVID-19 Wave in Poland, Lithuania, and Ukraine.

The SARS-CoV-2 pandemic affected the entire world and contributed to severe health and economic consequences. A safe and effective vaccine is a tool allowing the pandemic to be controlled. Hence, we aimed to conduct a survey on vaccinations against seasonal influenza and COVID-19 in Poland, Lithuania, and Ukraine. We also evaluated societal attitudes towards influenza and COVID-19 vaccinations. MATERIALS AND METHODS: We conducted the study between December 2020 and May 2021. At the time, the countries subject to the research were between the second and third waves of the COVID-19 pandemic. We used an anonymous and self-designed questionnaire comprised of eleven closed-ended questions and a short socio-demographic section. The questionnaire was administered by direct contact or mainly (due to the COVID-19 pandemic) by e-mail or Facebook. Finally, we included 2753 answers from Poland, 1852 from Ukraine, and 213 from Lithuania. RESULTS: Between 61% (Poland) and 72.9% (Ukraine) of the study participants have never been vaccinated against influenza (p < 0.05). Totals of 67.6% of the respondents in Poland, 73.71% in Lithuania, and 29.5% in Ukraine responded that they want to be vaccinated against COVID-19 (p < 0.05). Vaccine hesitancy was mainly related to worries about its side effects. There were also vaccine non-adopters in the study. In Ukraine, 67% of the respondents were clearly opposed to mandatory COVID-19 vaccines, compared to 41.7% in Poland and 30.99% in Lithuania (p < 0.05). CONCLUSIONS: There are still many people who present vaccine hesitancy or are opposed to vaccines. Thus, societal education about vaccination and the pandemic is crucial. Vaccine hesitancy or refusal might be related to vaccine origin. Shortages of influenza vaccines made it impossible to vaccinate those who were determined to be vaccinated. There is room for discussion of mandatory COVID-19 vaccinations.

COVID-19 Vaccine Hesitancy and Psychosocial Effects of the COVID-19 Pandemic among Health-Science Students of Lithuania-A National Cross-Sectional Online Survey.

(1) Background: the relationship between the psychosocial effects of the COVID-19 pandemic and COVID-19 vaccine hesitancy is understudied. Moreover, health science students are the future leaders and advocates of vaccination efforts. Therefore, it is essential to understand the origins of vaccine hesitancy and evaluate if the adverse psychosocial effects of the COVID-19 pandemic influence it. (2) Methods: we shared an anonymous questionnaire among health-science students via institutional emails of two Lithuanian universities. Results were summarized with odds ratios and mean differences. (3) Results: a total of 1545 health sciences students answered the questionnaire. Almost a fifth of the respondents claimed that they were unsure about getting vaccinated, and nearly one out of ten claimed that they would not get vaccinated. Medicine students, non-infected students, and students who volunteered in a COVID-19 ward were significantly more willing to get vaccinated compared to other health science students. Vaccine hesitant respondents reported a more significant negative effect of COVID-19 on their income and belief in the future. (4) Conclusions: the results of this study showed that negative psychosocial impact on income and 'belief in future' were positively associated with vaccine hesitancy. Having been diagnosed with COVID-19 was significantly associated with being doubtful towards vaccination.

COVID-19 pandemic-related aspects and predictors of emotional and behavioural symptoms in youth with pre-existing mental health conditions: results from Georgia, Lithuania, Romania, Serbia, and Turkey.

OBJECTIVE: This study evaluated levels of and predictors of emotional and behavioral symptoms in youth with pre-existing mental health conditions over the early phase of the COVID-19 pandemic in 2020 across Georgia, Lithuania, Romania, Serbia, and Turkey. METHODS: The study included 421 children and adolescents aged 5 - 18 years with pre-existing mental health conditions and corresponding ongoing treatments. We used a parent- and/or child-report, which taps into a broad range of mental health symptoms and contextual factors thought to be particularly pertinent during periods of social restrictions. Data were collected simultaneously across the countries from May 2020 to August 2020. RESULTS: According to parents, 121 (33.1%) children had deteriorations in the overall quality of mental health over the COVID-19, 156 (43.1%) deteriorations in the quantity of mental health care received, while 82 (25.1%) mental health care received did not meet the needs. For 121 (49.8%) of children, there was worsening in the main presenting psychiatric symptom compared to January 2020, while for 64 (26.3%) there was some improvement. In total, 128 (43.9%) children reported worsened emotional and 118 (40.6%) behavioral symptoms. The COVID-related worry, parental emotional difficulties, and parent-child relationships emerged as the most relevant predictors for higher levels of emotional and behavioral difficulties. CONCLUSIONS: This study found that the COVID-19 pandemic has considerably changed the daily lives of some children with pre-existing mental health conditions, where almost every second child had deteriorations in overall mental health or worsening of psychiatric symptoms.

Mental Health among Higher Education Students during the COVID-19 Pandemic: A Cross-Sectional Survey from Lithuania.

Mental health issues-anxiety, depression, suicidal ideation and behavior-are prevalent among students of higher education. The COVID-19 pandemic further affected students' daily life through academic and socioeconomic disturbances. We set out to investigate students' mental health amidst the COVID-19 pandemic and conducted a cross-sectional online survey at higher education institutions in Lithuania in 2021. The questionnaire consisted of the Hospital Anxiety and Depression scale (HADS) and the Sense of Coherence scale (SOC-3) questionnaires, evaluation of suicidal risk, experiences during the COVID-19 pandemic and self-rated health status (SRHS). Among 1001 students who completed the survey, the prevalence of clinically relevant anxiety was high (46.6%) and contrasted with the lower prevalence of depression (11.1%). 37.5% of all students admitted that they had thought about suicide at least once during their lifetime and a similar number of students thought about suicide during the previous year. High levels of anxiety and depression were statistically significant predictors of suicidal ideation and planning during the past year in binary regression models. High SRHS (higher score refers to more positive health status) was the only significant independent variable associated with less frequent suicidal attempts in the past year (p < 0.01, OR = 0.29, 95% CI = 0.12 to 0.66). Our study highlights anxiety and suicidality to be burdensome mental health issues among higher education students in Lithuania during the COVID-19 pandemic.

Persistence of SARS-CoV-2-Specific Antibodies for 13 Months after Infection.

BACKGROUND: Dynamics of antibody responses were investigated after a SARS-CoV-2 outbreak in a private company during the first wave of the pandemic. METHODS: Workers of a sewing company (Lithuania) with known SARS-CoV-2 RT-PCR result during the outbreak (April 2020) were invited to participate in the study. Virus-specific IgG and IgM were monitored 2, 6 and 13 months after the outbreak via rapid IgG/IgM serological test and SARS-CoV-2 S protein-specific IgG ELISA. RESULTS: Six months after the outbreak, 95% (CI 86-99%) of 59 previously infected individuals had virus-specific antibodies irrespective of the severity of infection. One-third of seropositive individuals had virus-specific IgM along with IgG indicating that IgM may persist for 6 months. Serological testing 13 months after the outbreak included 47 recovered individuals that remained non-vaccinated despite a wide accessibility of COVID-19 vaccines. The seropositivity rate was 83% (CI 69-91%) excluding one case of confirmed asymptomatic reinfection in this group. Between months 6 and 13, IgG levels either declined or remained stable in 31 individual and increased in 7 individuals possibly indicating an exposure to SARS-CoV-2 during the second wave of the pandemic. CONCLUSIONS: Detectable levels of SARS-CoV-2-specific antibodies persist up to 13 months after infection for the majority of the cases.

Factors Associated With Suicide Ideation in Lithuania and Poland Amid the COVID-19 Pandemic.

Background: The COVID-19 pandemic had an impact on many risk and protective factors associated with suicide. Aims: The aim of this study was to identify pandemic-related factors associated with suicidal ideation in the two European countries, Lithuania and Poland, amid the COVID-19 pandemic. Method: The sample comprised 2,459 participants in both countries; 57.2% of the respondents were female. The Mage of the participants was 43.45 years (SD = 15.91). Pandemic-related stressors and adjustment problems were measured to assess associations with suicidal ideation. Results: High levels of adjustment problems, loneliness, and burden due to staying at home more during the COVID-19 pandemic were significantly associated with suicide ideation in both Lithuania and Poland. Limitations: This was a cross-sectional online study with different recruitment approaches in the two countries. Conclusion: Adjustment problems, loneliness, and stressors related to staying at home more could be important targets for suicide prevention amid the pandemic.

Immunogenicity of the BNT162b2 COVID-19 mRNA vaccine and early clinical outcomes in patients with haematological malignancies in Lithuania: a national prospective cohort study.

BACKGROUND: Haematological malignancies and their treatments are likely to affect SARS-CoV-2 vaccine efficacy. We aimed to evaluate serological response to BNT162b2 vaccine in patients with haematological malignancies by type of treatment. METHODS: Our national prospective cohort study was done in Lithuania and assessed serological response to one and two BNT162b2 (Comirnaty, Pfizer-BioNTech) vaccine doses in healthy health-care workers and in patients with haematological malignancies. Eligible participants were aged 18 years or older, had received both vaccine doses, and had available biobanked blood samples from before vaccination and after the second dose. Biobanked samples and health data were obtained from Vilnius University Hospital Santaros Klinikos Biobank. Abbott Architect SARS-CoV-2 IgG Quant II chemiluminescent microparticle assay was used to quantify serum anti-SARS-CoV-2-S1 IgG antibody (anti-S1 IgG antibody) concentrations 0-10 days before the first BNT162b2 vaccine, on the day of second immunisation (around day 21), and 7 to 21 days after the second immunisation. Adverse events were assessed by a standardised questionnaire. Breakthrough infections were characterised clinically and by SARS-CoV-2 genotyping whenever possible. This study is registered with ClinicalTrials.gov, NCT04871165. FINDINGS: Between Jan 8 and April 21, 2021, 885 participants with haematological malignancies were included in the study. 857 patients were anti-S1 IgG seronegative at timepoint 0 and constituted the main analysis cohort. The age-matched comparison was made between 315 patients with haematological malignancies who were aged 18-60 years and 67 healthy health-care workers in the same age group. Patients aged 18-60 years with haematological malignancies had lower median anti-S1 IgG antibody responses after two BNT162b2 vaccine doses than did health-care workers of the same age group (median 6961 AU/mL [IQR 1292-20 672] vs 21 395 AU/mL [14 831-33 553]; p<0·0001). Compared with untreated patients with haematological malignancies (n=53; median 5761 AU/mL [629-16 141]), patients actively treated with Bruton tyrosine kinase inhibitors (BTKIs; n=44; 0 AU/mL [0-7]; p<0·0001), ruxolitinib (n=16; 10 AU/mL [0-45]; p<0·0001), venetoclax (n=10; 4 AU/mL [0-1218]; p=0·0005), or anti-CD20 antibody therapy (n=87; 17 AU/mL [1-2319]; p<0·0001) showed particularly poor anti-S1 IgG antibody responses following two BNT162b2 doses. Patients being treated with tyrosine kinase inhibitors (n=41; 10 537 AU/mL [IQR 2335-19 388]) or patients who received autologous haematopoietic stem-cell transplantation (HSCT; n=192; 6203 AU/mL [1451-16 834]) or allogeneic HSCT (n=122; 6304 AU/mL [1120-16 913]) were among the subgroups with the highest numerical responses. Nine SARS-CoV-2 infections and three COVID-19 deaths were observed among fully vaccinated patients with haematological malignancies. INTERPRETATION: Patients with haematological malignancies mount blunted and heterogeneous antibody responses to the full course of BNT162b2 mRNA vaccination. Patients who are actively treated with BTKIs, ruxolitinib, venetoclax, or anti-CD20 antibody therapies seem to be the most negatively affected and might be left unprotected from SARS-CoV-2 infection. Breakthrough severe SARS-CoV-2 infections in fully vaccinated patients with haematological malignancies emphasise the importance of ongoing strict adherence to non-pharmacological interventions and household vaccination while SARS-CoV-2 is circulating in the community. FUNDING: Vilnius University Hospital Santaros Klinikos. TRANSLATION: For the Lithuanian translation of the abstract see Supplementary Materials section.