Comparative Profiles of SARS-CoV-2 Spike-Specific Human Milk Antibodies Elicited by mRNA- and Adenovirus-Based COVID-19 Vaccines.

Background: Numerous COVID-19 vaccines are authorized globally. To date, ∼71% of doses comprise the Pfizer/BioNTech vaccine, and ∼17% the Moderna/NIH vaccine, both of which are messenger RNA (mRNA) based. The chimpanzee Ad-based Oxford/AstraZeneca (AZ) vaccine comprises ∼9%, while the Johnson & Johnson/Janssen (J&J) human adenovirus (Ad26) vaccine ranks fourth at ∼2%. No COVID-19 vaccine is yet available for children 0-4. One method to protect this population may be passive immunization through antibodies (Abs) provided in the milk of a lactating vaccinated person. Our early work and other reports have demonstrated that unlike the post-SARS-CoV-2 infection milk Ab profile, which is rich in specific secretory (s)IgA, the vaccine response is highly IgG dominant. Results: In this report, we present a comparative assessment of the milk Ab response elicited by Pfizer, Moderna, J&J, and AZ vaccines. This analysis revealed 86-100% of mRNA vaccine recipient milk exhibited Spike-specific IgG endpoint titers, which were 12- to 28-fold higher than those measured for Ad vaccine recipient milk. Ad-based vaccines elicited Spike-specific milk IgG in only 33-38% of recipients. Specific IgA was measured in 52-71% of mRNA vaccine recipient milk and 17-23% of Ad vaccine recipient milk. J&J recipient milk exhibited significantly lower IgA than Moderna recipients, and AZ recipients exhibited significantly lower IgA titers than Moderna and Pfizer. Less than 50% of milk of any group exhibited specific secretory Ab, with Moderna recipient IgA titers measuring significantly higher than AZ. Moderna appeared to most frequently elicit greater than twofold increases in specific secretory Ab titer relative to prevaccine sample. Conclusion: These data indicate that current Ad-based COVID-19 vaccines poorly elicit Spike-specific Ab in milk compared to mRNA-based vaccines, and that mRNA vaccines are preferred for immunizing the lactating population. This study highlights the need to design vaccines better aimed at eliciting an optimal milk Ab response.

Qualitative immunoassay for the detection of anti-SARS-COV-2 spike antibody in human milk samples.

Antibodies in milk obtained from those previously SARS-CoV-2-infected or vaccinated against COVID-19 may provide passive immunity to the breastfed infant. Few assays have been established to measure antibodies in human milk, despite the public health importance of this topic. In the present protocol, we describe an optimized indirect ELISA assay aimed to measure SARS-CoV-2-reactive antibodies in human milk, which can be used as a rapid screen on undiluted samples or to designate samples as relatively low, moderate, or high titer. For complete details on the use and execution of this protocol, please refer to Fox et al. (2020).

Risk Assessment and Prevention of Severe Acute Respiratory Syndrome Coronavirus 2 Transmission for Hospitalized Urological Patients After the COVID-19 Pandemic in Wuhan, China.

BACKGROUND: Emerging asymptomatic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections were detected and multiple cases were found to be SARS-CoV-2 positive again, which raised an alarm for the patients hospitalized after the coronavirus disease 2019 (COVID-19) pandemic. OBJECTIVE: We investigated the risk and prevention of hospital transmission of SARS-CoV-2 to hospitalized urological patients. DESIGN SETTING AND PARTICIPANTS: This is a retrospective study of 319 hospitalized urological patients enrolled between April 20, 2020 and May 11, 2020 from two tertiary hospitals in Wuhan, China. INTERVENTION: Chest computed tomography (CT) images, nucleic acid tests (NATs), and serum antibody were examined at the outpatient department and 1 wk after admission for all patients. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The chest CT images, NATs, serum antibody results, and clinical data were collected and analyzed. RESULTS AND LIMITATIONS: None of the 319 patients was found to be SARS-CoV-2 NAT positive. Ten and four patients were detected to be immunoglobulin (Ig)G and IgM positive, respectively. The chest CT features of 116 patients showed abnormal lung findings. During the 1-wk isolation, one patient initially being IgG positive only was found to be IgM positive, and another initially IgM-positive patient had a rising IgG level. Through risk assessment, we identified seven patients with very high and high risk for hospital transmission, and delayed the surgery while maintaining close follow-up. Five intermediate-risk patients were operated on successfully under paravertebral block or epidural anesthesia to avoid opening the airway with endotracheal intubation. The remaining 104 low-risk and 203 normal patients underwent normal surgery. CONCLUSIONS: Of the 319 patients, seven were identified as very high and high risk, which reinforced the importance of epidemic surveillance of discharged COVID-19 patients and asymptomatic infections. Five intermediate-risk patients were operated on successfully under regional anesthesia. PATIENT SUMMARY: Our experience of risk assessment and management practice may provide a strategy to prevent severe acute respiratory syndrome coronavirus 2 transmission to hospitalized urological patients after the coronavirus disease 2019 (COVID-19) pandemic.