Analysis of COVID-19 Incidence and Protective Potential of Persisting IgG Class Antibodies against SARS-CoV-2 Infection in Hospital Staff in Poland

The immune responses to both SARS-CoV-2 infection and vaccines are of key importance in prevention efforts. In April and May 2020, 703 study participants tested for COVID-19 by PCR tests were registered. In June and July 2020, they were examined for the presence of SARS-CoV-2 S1/S2 IgG. From October 2020 to January 2021, those among the study population with COVID-19 confirmed by PCR tests were registered, and the same group of participants was invited to be examined again for the presence of SARS-CoV-2 antibodies. In June 2020, antibodies were detected in only 88% of those who had PCR-confirmed COVID-19 in April-May 2020, which suggests that a significant proportion of persons in the Polish population do not produce antibodies after contact with SARS-CoV-2 antigens or rapidly lose them and reach levels below the lab detection limit. The levels of IgG class anti-SARS-CoV-2 antibodies were significantly lower among people who previously had COVID-19 than for those who had received COVID-19 vaccination, which confirms the high immunogenicity of the vaccines against COVID-19 in the Polish population. The study confirms that a detectable level of IgG class anti-SARS-CoV-2 antibodies cannot be considered a reliable marker of the presence and strength of COVID-19 immunity preventing individuals from acquiring SARS-CoV-2 infection.

How SARS-CoV-2 Transformed the Clinical Laboratory: Challenges and Lessons Learned

The COVID-19 pandemic has made a devastating impact on global health and continues to challenge healthcare infrastructure and delivery. The clinical laboratories were no exception as they are responsible for diagnostic testing that dictates many clinical, infection control and public health decisions. Information technology and laboratory management tools are critical assets for maintaining and adapting operations in response to crises and when utilized effectively, promote the integration between the clinical laboratory specialties (e.g., chemistry, hematology, microbiology, and molecular pathology). During the COVID-19 pandemic, our systems and processes were strained due to high testing volumes, demand for rapid turnaround times, supply chain constraints, and constantly evolving testing algorithms and result interpretations as our knowledge of the virus and of diagnostics increased over time. In this report, we describe those challenges and subsequent adaptations made by each clinical laboratory section. We hope these details help provide potential solutions and approaches for other hospitals facing COVID-19 surges or other future pandemics.

Preprocedural SARS-CoV-2 Testing to Sustain Medically Needed Health Care Delivery During the COVID-19 Pandemic: A Prospective Observational Study

BACKGROUND

We implemented a preprocedural severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) screening initiative designed to sustain health care during a time when the extent of SARS-CoV-2 infection was unknown.

METHODS

This was a prospective study of patients undergoing procedures at 3 academic hospitals in Pittsburgh, Pennsylvania (April 21-June 11), and 19 community hospitals across Middle/Western Pennsylvania and Southwestern New York (May 1-June 11). Patients at academic hospitals underwent symptom screening ≤7 days preprocedure, then SARS-CoV-2 nasopharyngeal polymerase chain reaction (PCR) testing 1-4 days preprocedure. A subset also underwent day-of-procedure testing. Community hospital patients underwent testing per local protocols. We report SARS-CoV-2 PCR positivity rates, impact, and barriers to testing encountered through June 11. PCR positivity rates of optional preprocedural SARS-CoV-2 testing for 2 consecutive periods following the screening initiative are also reported.

RESULTS

Of 5881 eligible academic hospital patients, 2415 (41.1%) were tested (April 21-June 11). Lack of interest, distance, self-isolation, and nursing home/incarceration status were barriers. There were 11 PCR-positive patients (10 asymptomatic) among 10 539 patients tested (0.10%; 95% CI, 0.05%-0.19%): 3/2415 (0.12%; 95% CI, 0.02%-0.36%) and 8/8124 (0.10%; 95% CI, 0.04%-0.19%) at academic and community hospitals, respectively. Procedures were performed as scheduled in 40% (4/10) of asymptomatic PCR-positive patients. Positivity increased during subsequent coronavirus disease 2019 (COVID-19) surges: 54/34 948 (0.15%; 95% CI, 0.12%-0.20%) and 101/24 741 (0.41%; 95% CI, 0.33%-0.50%) PCR-positive patients from June 12-September 10 and September 11-December 15, respectively (P < .0001).

CONCLUSIONS

Implementing preprocedural PCR testing was complex and revealed low infection rates (0.24% overall), which increased during COVID-19 surges. Additional studies are needed to define the COVID-19 prevalence threshold at which universal preprocedural screening is warranted.