The coronavirus disease 2019 (COVID-19) pandemic, caused by the SARS-CoV-2 virus, has rapidly evolved since late 2019, due to highly transmissible Omicron variants. While most Canadian paramedics have received COVID-19 vaccination, the optimal ongoing vaccination strategy is unclear. We investigated neutralizing antibody (NtAb) response against wild-type (WT) Wuhan Hu-1 and Omicron BA.4/5 lineages based on the number of doses and past SARS-CoV-2 infection, at 18 months post initial vaccination (with a Wuhan Hu-1 platform mRNA vaccine [BNT162b2 or mRNA-1273}). Demographic information, previous COVID-19 vaccination, infection history, and blood samples were collected from paramedics 18 months post initial mRNA COVID-19 vaccine dose. Outcome measures were ACE2 percent inhibition against Omicron BA.4/5 and WT antigens. We compared outcomes based on number of vaccine doses (two vs. three) and previous SARS-CoV-2 infection status, using the Mann-Whitney U test. Of 657 participants, the median age was 40 years (IQR 33-50) and 251 (42%) were females. Overall, median percent inhibition to BA.4/5 and WT was 71.61% (IQR 39.44-92.82) and 98.60% (IQR 83.07-99.73), respectively. Those with a past SARS-CoV-2 infection had a higher median percent inhibition to BA.4/5 and WT, when compared to uninfected individuals overall and when stratified by two or three vaccine doses. When comparing two vs. three WT vaccine doses among SARS-CoV-2 negative participants, we did not detect a difference in BA.4/5 percent inhibition, but there was a difference in WT percent inhibition. Among those with previous SARS-CoV-2 infection(s), when comparing two vs. three WT vaccine doses, there was no observed difference between groups. These findings demonstrate that additional Wuhan Hu-1 platform mRNA vaccines did not improve NtAb response to BA.4/5, but prior SARS-CoV-2 infection enhances NtAb response.
The coronavirus disease 2019 (COVID-19) pandemic, caused by the SARS-CoV-2 virus, has rapidly evolved since late 2019, due to highly transmissible Omicron variants. While most Canadian paramedics have received COVID-19 vaccination, the optimal ongoing vaccination strategy is unclear. We investigated neutralizing antibody (NtAb) response against wild-type (WT) Wuhan Hu-1 and Omicron BA.4/5 lineages based on the number of doses and past SARS-CoV-2 infection, at 18 months post initial vaccination (with a Wuhan Hu-1 platform mRNA vaccine [BNT162b2 or mRNA-1273}). Demographic information, previous COVID-19 vaccination, infection history, and blood samples were collected from paramedics 18 months post initial mRNA COVID-19 vaccine dose. Outcome measures were ACE2 percent inhibition against Omicron BA.4/5 and WT antigens. We compared outcomes based on number of vaccine doses (two vs. three) and previous SARS-CoV-2 infection status, using the Mann-Whitney U test. Of 657 participants, the median age was 40 years (IQR 33-50) and 251 (42%) were females. Overall, median percent inhibition to BA.4/5 and WT was 71.61% (IQR 39.44-92.82) and 98.60% (IQR 83.07-99.73), respectively. Those with a past SARS-CoV-2 infection had a higher median percent inhibition to BA.4/5 and WT, when compared to uninfected individuals overall and when stratified by two or three vaccine doses. When comparing two vs. three WT vaccine doses among SARS-CoV-2 negative participants, we did not detect a difference in BA.4/5 percent inhibition, but there was a difference in WT percent inhibition. Among those with previous SARS-CoV-2 infection(s), when comparing two vs. three WT vaccine doses, there was no observed difference between groups. These findings demonstrate that additional Wuhan Hu-1 platform mRNA vaccines did not improve NtAb response to BA.4/5, but prior SARS-CoV-2 infection enhances NtAb response.
Introduction Comparative immunogenicity from different mRNA booster vaccines (directed at wild-type [WT], BA.1, or BA.4/5 antigens) remains unclear. Methods We included blood samples from adult paramedics who received three mRNA WT-directed vaccines plus a fourth dose of: (1) WT monovalent; (2) Moderna BA.1-WT bivalent; or (3) Pfizer BA.4/5-WT bivalent vaccine. The primary outcome was angiotensin-converting enzyme 2 (ACE-2) inhibition to BA.4/5 antigen. We used optimal pair matching (using age, sex-at-birth, preceding SARS-CoV-2 infection, and fourth vaccine-to-blood collection interval) to create balanced groups to individually compare each vaccine type to each other vaccine (overall, within subgroups defined by SARS-CoV-2 infection, and after combining BA.1 and BA.4/5 cases). We compared outcomes with Wilcoxon matched pairs signed rank test. Results Overall, 158 paramedics (mean age 45 years) were included. ACE-2 inhibition was higher for BA.1 compared to WT (p=0.002); however, no difference was detected between BA.4/5 vs. WT, or BA.1 vs BA.4/5. Among cases with preceding SARS-CoV-2, there were no between-group differences. Among cases without preceding SARS-CoV-2, the only difference was BA.1 > WT (p=0.003). BA.1 and BA.4/5 cases combined had higher ACE2 inhibition than WT (p = 0.003). Conclusion Omicron-directed vaccines appear to improve Omicron-specific immunogenicity; however, this appears limited to SARS-CoV-2-naïve individuals.
This study investigated the association between previous severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and risk of symptoms associated with post-COVID conditions among fully vaccinated paramedics in Canada. We included vaccinated paramedics who provided blood sample and questionnaire data on the same date during the study period. We examined the presence of symptoms associated with post-COVID conditions and depression severity against prior SARS-CoV-2 infection categories. Compared to the "no previous SARS-CoV-2 infection" group, there was no detected association between known prior SARS-CoV-2 infection (odds ratio [OR], 1.42 [95% confidence interval {CI}, 0.96-2.09]), nor unknown prior SARS-CoV-2 infection (OR, 0.54 [95% CI, 0.29-1.00]), and the presence of symptoms associated with post-COVID conditions.
Emergency medical services workers, such as paramedics, provide important emergency care and may be exposed to potential carcinogens while working. Few studies have examined the risk of cancer among paramedics demonstrating an important knowledge gap in existing literature. This study aimed to investigate cancer risks among paramedics in a large cohort of Ontario workers.
Psychological effects of withholding treatment that could have benefited a patient during a pandemic remain largely unknown. It is also unclear to what extent their reasons for withholding treatment contributed to the subsequent impact on mental health outcomes. Paramedics may have withheld treatments either due to fear of exposure, being directed by their service, or both. As such, the present research aimed to characterize withholding treatment and investigate potential negative mental health outcomes.
Materials and Methods
Paramedics from five provinces (Alberta, British Columbia, Manitoba, Ontario, Saskatchewan) working during the COVID-19 pandemic completed online questionnaires assessing withholding treatment (i.e., due to fear of exposure, directed by their service, or both), and mental health outcomes including depression (PHQ-9) and post-traumatic stress (PTSD) symptoms (PC-PTSD-5) as part of the COVID-19 Occupational Risks, Seroprevalence and Immunity among Paramedics (CORSIP) study.
Results
Of the 1453 participants, 54.2% reported withholding treatment due to fear of exposure (4.3%), as directed by their service (76.5%) or both (19.2%). Participants who withheld treatment reported higher rates of PTSD (M=2.6, p < .01) and depression (M=8.2, p < .001) symptoms than those that did not withhold treatments (MPTSD=2.3; Mdepression=6.4). Reason for withholding treatment and PTSD symptom severity were associated (p<.01). Paramedics who withheld treatment due to fear of exposure were more likely to report probable PTSD symptoms (23.5%) than those who withheld treatments as directed by their service (8.7%) or both (12.2%). Depression symptom severity did not differ by reasons for withholding treatment.
Conclusions
Withholding treatment is potentially traumatic and may influence the development of depression and PTSD symptoms. Withholding due to fear of exposure rather than being directed to increased PTSD symptoms. Further research will investigate the mental health impact of withholding treatment and reported reasons for withholding over time.
Paramedics have treated many patients suspected of having COVID-19 throughout this pandemic. The uncertainty regarding COVID-19 contagion, effectiveness of infection protection and controls, and the uncontrolled environments in which paramedics work may adversely impact their mental health.
Objectives
To characterize the impact of the COVID-19 pandemic on the mental health of Canadian paramedics using preliminary data.
Methods
Self-reported questionnaire data was collected from paramedics across five Canadian provinces as part of the COVID-19 Occupational Risks, Seroprevalence and Immunity among Paramedics (CORSIP) project. Validated screening scores were calculated for major depressive disorder (MDD, PHQ-9 questionnaire) and probable post-traumatic stress disorder (PTSD, PC-PTSD-5 questionnaire). Satisfaction with life (SWL) measures were adapted from validated Canadian Census questions and confirmed by reliability analysis. Bivariate relationships of screening scores were analyzed using Wilcoxon signed-ranked, Cliff's d, and differences in proportions tests where appropriate.
Results
Completed questionnaires from 1,906 recruited paramedics were analyzed (95% completion rate). The overall prevalence of MDD was 31.6%. Suicidal ideation (i.e., 'thoughts that you would be better off dead, or of hurting yourself in some way') was reported by 8.3% of paramedics. In addition, 40.2% of paramedics screened positive for probable PTSD, with no significant difference being reported before vs. during the pandemic. Paramedics reported higher median SWL prior to the COVID-19 pandemic (20 vs. 16, p<0.001). There was a large effect size (d=0.52), suggesting a greater probability that paramedics would report higher SWL prior to COVID-19.
Conclusion
Canadian paramedics appear to be at risk for MDD and PTSD. While the proportion of paramedics with probable PTSD does not appear to have changed during the pandemic, a reduction in SWL was observed. Incorporating follow-up data that will be collected from participants over the next year will be imperative to assess the stability of these findings and evaluate differences by province.
