Differences in mRNA-1273 (Moderna) and BNT162b2 (Pfizer-BioNTech) SARS-CoV-2 vaccine immunogenicity among patients undergoing dialysis.

BACKGROUND: Differences in immunogenicity between mRNA SARS-CoV-2 vaccines have not been well characterized in patients undergoing dialysis. We compared the serologic response in patients undergoing maintenance hemodialysis after vaccination against SARS-CoV-2 with BNT162b2 (Pfizer-BioNTech) and mRNA-1273 (Moderna). METHODS: We conducted a prospective observational cohort study at 2 academic centres in Toronto, Canada, from Feb. 2, 2021, to July 20, 2021, which included 129 and 95 patients who received the BNT162b2 and mRNA-1273 SARS-CoV-2 vaccines, respectively. We measured SARS-CoV-2 immunoglobulin G antibodies to the spike protein (anti-spike), receptor binding domain (anti-RBD) and nucleocapsid protein (anti-NP) at 6-7 and 12 weeks after the second dose of vaccine and compared those levels with the median convalescent serum antibody levels from 211 controls who were previously infected with SARS-CoV-2. RESULTS: At 6-7 weeks after 2-dose vaccination, we found that 51 of 70 patients (73%) who received BNT162b2 and 83 of 87 (95%) who received mRNA-1273 attained convalescent levels of anti-spike antibody (p < 0.001). In those who received BNT162b2, 35 of 70 (50%) reached the convalescent level for anti-RBD compared with 69 of 87 (79%) who received mRNA-1273 (p < 0.001). At 12 weeks after the second dose, anti-spike and anti-RBD levels were significantly lower in patients who received BNT162b2 than in those who received mRNA-1273. For anti-spike, 70 of 122 patients (57.4%) who received BNT162b2 maintained the convalescent level versus 68 of 71 (96%) of those who received mRNA-1273 (p < 0.001). For anti-RBD, 47 of 122 patients (38.5%) who received BNT162b2 maintained the anti-RBD convalescent level versus 45 of 71 (63%) of those who received mRNA-1273 (p = 0.002). INTERPRETATION: In patients undergoing hemodialysis, mRNA-1273 elicited a stronger humoral response than BNT162b2. Given the rapid decline in immunogenicity at 12 weeks in patients who received BNT162b2, a third dose is recommended in patients undergoing dialysis as a primary series, similar to recommendations for other vulnerable populations.

Evaluation of the SARS-CoV-2 Antibody Response to the BNT162b2 Vaccine in Patients Undergoing Hemodialysis.

Importance: Patients undergoing hemodialysis have a high mortality rate associated with COVID-19, and this patient population often has a poor response to vaccinations. Randomized clinical trials for COVID-19 vaccines included few patients with kidney disease; therefore, vaccine immunogenicity is uncertain in this population. Objective: To evaluate the SARS-CoV-2 antibody response in patients undergoing chronic hemodialysis following 1 vs 2 doses of BNT162b2 COVID-19 vaccination compared with health care workers serving as controls and convalescent serum. Design, Setting, and Participants: A prospective, single-center cohort study was conducted between February 2 and April 17, 2021, in Toronto, Ontario, Canada. Participants included 142 patients receiving in-center hemodialysis and 35 health care worker controls. Exposures: BNT162b2 (Pfizer-BioNTech) COVID-19 vaccine. Main Outcomes and Measures: SARS-CoV-2 IgG antibodies to the spike protein (anti-spike), receptor binding domain (anti-RBD), and nucleocapsid protein (anti-NP). Results: Among the 142 participants undergoing maintenance hemodialysis, 94 (66%) were men; median age was 72 (interquartile range, 62-79) years. SARS-CoV-2 IgG antibodies were measured in 66 patients receiving 1 vaccine dose following a public health policy change, 76 patients receiving 2 vaccine doses, and 35 health care workers receiving 2 vaccine doses. Detectable anti-NP suggestive of natural SARS-CoV-2 infection was detected in 15 of 142 (11%) patients at baseline, and only 3 patients had prior COVID-19 confirmed by reverse transcriptase polymerase chain reaction testing. Two additional patients contracted COVID-19 after receiving 2 doses of vaccine. In 66 patients receiving a single BNT162b2 dose, seroconversion occurred in 53 (80%) for anti-spike and 36 (55%) for anti-RBD by 28 days postdose, but a robust response, defined by reaching the median levels of antibodies in convalescent serum from COVID-19 survivors, was noted in only 15 patients (23%) for anti-spike and 4 (6%) for anti-RBD in convalescent serum from COVID-19 survivors. In patients receiving 2 doses of BNT162b2 vaccine, seroconversion occurred in 69 of 72 (96%) for anti-spike and 63 of 72 (88%) for anti-RBD by 2 weeks following the second dose and median convalescent serum levels were reached in 52 of 72 patients (72%) for anti-spike and 43 of 72 (60%) for anti-RBD. In contrast, all 35 health care workers exceeded the median level of anti-spike and anti-RBD found in convalescent serum 2 to 4 weeks after the second dose. Conclusions and Relevance: This study suggests poor immunogenicity 28 days following a single dose of BNT162b2 vaccine in the hemodialysis population, supporting adherence to recommended vaccination schedules and avoiding delay of the second dose in these at-risk individuals.

Gonadotropina coriónica en flujo vaginal para el diagnóstico de rotura prematura de membranas / Chorionic gonadotrophin in vaginal discharge for diagnosis of premature rupture of membranes

Objetivo: Establecer la eficacia diagnóstica de la determinación de gonadotropina coriónica en flujo vaginal para el diagnóstico de la rotura prematura de membranas. Método: Investigación de tipo prospectiva en muestra de 270 embarazadas que asistieron al Hospital Central "Dr. Urquinaona", Maracaibo, Venezuela. Los grupos consistieron en pacientes con rotura prematura de membranas (grupo A; n = 135) y embarazadas con membranas integras (grupo B; n = 135), consideradas como controles. Se evaluaron las características generales, valores de gonadotropina coriónica en flujo vaginal y efectividad diagnóstica. Resultados: La edad gestacional al momento de la determinación de las concentraciones de gonadotropina coriónica en flujo vaginal fue de 32,9 +/- 1,6 semanas para el grupo A y 33,1 +/- 1,9 semanas para el grupo B (p = ns). No se encontraron diferencias estadísticamente significativas en la edad materna y la frecuencia de paridad entre ambos grupos de tratamiento (p = ns). Las pacientes del grupo A presentaron concentraciones significativamente más altas de gonadotropina coriónica en flujo vaginal (697,4 +/- 382,4 mUI/mL) comparado con las embarazadas del grupo B (91,4 +/- 47,1 mUI/mL; p < 0,0001). Un valor de corte de 100 mUI/mL presentó un valor por debajo de la curva de 0,96 con una sensibilidad del 97,0 por ciento, especificidad del 51,1 por ciento, valor predictivo positivo del 66,5 por ciento y valor predictivo negativo del 94,5 por ciento. Conclusión: La determinación de las concentraciones de gonadotropina coriónica en el flujo vaginal es una técnica diagnóstica útil para la rotura prematura de membranas.

Objective: To establish the diagnostical efficacy of chorionic gonadotropin in vaginal fluid determination for diagnosis of premature rupture of membranes. Method: A prospective research type was done with a sample of 270 pregnant women who assisted to obstetrics emergency at Hospital Central "Dr. Urquinaona", Maracaibo, Venezuela. Groups consisted in patients with premature rupture of membranes (group A; n = 135) and pregnant women with intact membranes (group B; n = 135), considered as controls. General characteristics, values of chorionic gonadotropin in vaginal fluid and diagnostic efficacy were evaluated. Results: Gestational age at the moment of determination chorionic gonadotropin in vaginal fluid was 32.9 +/- 1.6 weeks in group A and 33.1 +/- 1.9 weeks in group B (p = ns). There were no significant differences in maternal age and frequency of parity between groups (p = ns). Patients in group A showed significant higher concentrations of chorionic gonadotropin in vaginal fluid (697.4 +/- 382.4 mUI/mL) compared with pregnant women in group B (91.4 +/- 47.1 mUI/mL; p < 0.0001). A cut-off point of 100 mUI/mL showed a under the curve value of 0.96 with a sensitivity of 97.0 percent, specificity of 51.1 percent, positive predictive value of 66.5 percent and negative predictive value of 94.5 percent. Conclusions: Determination of chorionic gonadotropin concentrations in vaginal fluid is a useful diagnosis tool for premature rupture of membranes.