In February 2021, Polish teachers were offered the ChAdOx1-S vaccine as a priority group. However, there have been concerns among educators regarding the efficacy of this vaccine, as compared to the other types of vaccines (e.g., mRNA). The objective of this study was to investigate the reactogenicity and the immunogenicity of this vaccine. Participants, specifically teachers, were invited for serological testing ≥ 4 weeks post-vaccination. Antibodies against the receptor-binding domain (RBD) were measured. Of the 192 participants, the mean age was 50.5 ± 8.3 years and the mean (range) dosing interval was 69.6 ± (25–111) days. Adverse reactions included feeling feverish (44.8%), headache (41.7%), malaise/chills (38.0%), and injection-site tenderness (37.5%); these were reported more frequently after the first dose (84.9%). Fewer males than females (54.8% vs. 80.1%) and fewer older participants (65.7% vs. 90.4%) reported side effects (p < 0.002; p < 0.0001, respectively). All participants presented detectable anti-RBD IgG; the median (range) reading was 525.0 BAU/mL (20.6–5680.0); 1008.02 BAU/mL (115.3–5680.0) in those with prior SARS-CoV-2 infection; and 381.42 BAU/mL (20.6–3108.8) in those without (p = 0.001). In 27.6%, the anti-RBD IgG level was >500 BAU/mL. A multivariate logistic regression revealed that previous infection and longer dose intervals were predictors of higher immunologic responses (p < 0.0001; p = 0.01, respectively). The results demonstrated good tolerability and immunogenicity of the ChAdOx1-S vaccine. Our study justified the longer dose interval to enhance a higher antibody response. Our findings may also support the prioritization of uninfected individuals in regions where COVID-19 vaccine-sparing strategies are required.

Background Migrants’ access to healthcare services is limited. This study aimed to identify health system barriers to vaccination, specifically HPV/MMR vaccination among children in Ukrainian economic migrants (UMs). Methods Between December 2021–March 2022, a qualitative study of UMs living in Poland was conducted. Six focus groups were held with 53 UMs aged 15–45; in-depth interviews with 12 healthcare workers (HCWs) were also performed. A thematic analysis was conducted based on the six WHO health system building blocks. Results HCWs described gaps in integrating migrant status in accessible healthcare data which impeded active management of vaccination procedures. UMs reported that the digitization of healthcare services, intensified during the COVID-19 pandemic, reduced their access to primary care. Inadequate health information systems caused problems with the provision of credible vaccine information in translated forms, and language difficulties, experienced by both UMs and HCWs; this was enhanced by a lack of professional interpreting services. Although most UMs reported vaccinating children according to the Polish schedule, the variations in schedules across countries caused concern among UMs and increased HCWs’ uncertainty about how to interpret vaccination cards, particularly in the context of possible false certificates. UMs were affected by discrimination through HCWs. HPV was deprioritized by UMs due to misconceptions about non-mandatory vaccinations; the cost was also a barrier. Conclusions The study findings have implications for migrant vaccination delivery targeting children in Poland, and other UMs receiving countries. A concerted effort is required to improve UM’s awareness of the significance of vaccinations. Barriers to healthcare access must be recognized by policymakers. Importantly, removing the cost barrier may increase the uptake of the HPV vaccine among Ukrainian migrant adolescents.

Background The constantly growing refugee population may constitute public health threat in Poland in the context of COVID-19 pandemic. This study objective was to investigate COVID-19 knowledge among Ukrainian refugees in Poland. Methods This cross-sectional study was carried out between March-April 2022 among Ukrainian refugees registering in Zielona Góra, Poland. An anonymous, self-administered questionnaire was used which included 10 questions related to COVID-19 knowledge. Each correct answer was given 1 point. Results Response rate was 96.0%, 190 Ukrainians responded (mean age 37.8±15.7 years; 42.1% males); 52.1% were living in the cities &gt;50,000 inhabitants; 61.6% reported high SES; 39% higher education; 44.2% were married. The mean knowledge score was 3.47 (SD ± 2.2), 15.8% collected &gt;50% points. The knowledge level was higher among those with higher SES (p &lt; 0.0001) and higher education (p = 0.003); 31.7% stated that SARS-CoV-2 is an animal-human transmitted disease (more with high SES, p = 0.004), 55.0% considered COVID-19 as highly contagious disease (more living in bigger cities, p = 0.04), 26.3% reported that SARS-CoV-2 infection ensures lifetime immunity (more unmarried, p = 0.02); 24.7% correctly stated that compared with 18- to 30-year-olds COVID-19 mortality rate is about 10 times higher in those who are &gt;65 years (more with higher education and high SES; p &lt; 0.05, p = 0.01 respectively), 44.4% - that COVID-19 treatments are now available (more with high SES and higher education; p = 0.03 both). Regarding prevention, 37.0% reported that FFP3 is the most protective type of mask, 43.3% that vaccines effectively protect against COVID-19 (more with high SES; p = 0.006, p &lt; 0.001 respectively). Conclusions COVID-19 knowledge among Ukrainian refugees in Poland was far unsatisfactory, in particular among those with lower education and lower SES. Educational campaigns are urgently needed to effectively raise the knowledge level in this vulnerable group to better control the pandemic. Key messages • This study results may be used by public health experts to expand educational campaigns targeting Ukrainian refugees in Poland. • COVID-19 education oriented to Ukrainian refugees in Poland should specifically address deficits of knowledge identified in this study.

Background Polish teachers, as the priority group, were offered the ChAdOx1-S vaccine since February 2021. The objective was to investigate safety, tolerability and immunogenicity of this vaccine following two vaccine doses. Methods Teachers were invited for serological testing ≥8 weeks after second vaccination. Quantitative post-vaccination anti-spike antibody responses were measured using the Abbott SARS-CoV-2 IgG II Quant assay (detection threshold: ≥7.1 BAU/ml). Multivariable logistic regression methods were used to identify predictors of immunogenicity. Results Of 192 teachers, mean age 50.5±8.3 years, 83.9% were females. Median (range) dosing interval was 50 (14-95) days; median interval between the second dose and immunogenicity test was 69 days (range: 57–111). More than a half of teachers (58.3%) reported they would change the product for another (mostly mRNA) vaccine if there was such an opportunity. Adverse reactions after receiving the vaccine (either the first or the second dose) were reported by 79.2% teachers, more frequently after the first dose (84.9%), and were similar in nature to those previously reported: feeling feverish (44.8%), headache (41.7%), malaise, chills (both: 38.0%), injection-site tenderness (37.5%) and pain (32.3%). Less males than females (54.8% vs 80.1%) and older (aged ≥50 years) than younger teachers (65.7% vs 90.4%) reported side effects (p<0.002; p<0.0001, respectively). By ≥8 weeks after the boost dose, all teachers had neutralizing antibody responses. The median (range) anti-spike IgG reading was 525.0 BAU/mL (20.6-5680.0 BAU/mL); 1008.02 (115.3–5680.0) BAU/mL in teachers with evidence of prior infection and 381.42 BAU/mL (20.6–3108.8) in those without (p=0.001). Previous infection with SARS-CoV-2 and longer dose interval were both positive predictors of higher immunologic response (p<0.0001; p=0.01, respectively), with no evidence of differences by age, gender, BMI, smoking or comorbidities. Conclusions The results demonstrated good safety, tolerability and immunogenicity of the ChAdOx1-S vaccine. Immunization led to detectable anti-spike antibodies in all teachers. Our study justifies the longer dose interval as an important factor to enhance higher antibody response. Findings suggest that in immunocompetent vaccine recipients with an evidence of previous infection a delay regarding the second dose could be considered when careful management in the use of vaccine resources is needed.