Humoral immune response to SARS-CoV-2 in pregnant and non-pregnant women following infection

Background Immune changes that occur during pregnancy may place pregnant women at an increased risk for severe disease following viral infections like SARS-CoV-2. Whether these immunological changes modify immune response to SARS-CoV-2 infection during pregnancy is not well understood. Objective The objective of the present study is to compare humoral immune response to SARS-CoV-2 infection in pregnant and non-pregnant women. Immune response following vaccination for SARS-CoV-2 was also explored. Study Design In the present cohort study, 24 serum samples from 20 patients infected with SARS-CoV-2 during pregnancy were matched on number of days post positive test to 46 samples from 40 non-pregnant women of reproductive age. Samples from nine patients vaccinated during pregnancy were also examined. Immunoglobulin G (IgG) and immunoglobulin M (IgM) antibody levels were measured. Trends in log antibody levels over time and mean antibody levels were assessed using generalized estimating equations. Results Median number of days from first positive test to sampling was 6.5 in the pregnant group (range 3-97) and 6.0 among non-pregnant participants (range 2-97). No significant differences in demographic or sampling characteristics were noted between groups. No differences in IgG or IgM levels over time or mean antibody levels were noted in pregnant and non-pregnant participants following SARS-CoV-2 infection for any of the SARS-CoV-2 antigens targets examined [Spike, Spike Receptor Binding Domain (RBD), Spike N-Terminal Domain (NTD), and Nucleocapsid]. Participants vaccinated during pregnancy had higher IgG levels than pregnant positive patients for all SARS-CoV-2 targets except Nucleocapsid (all p < 0.001), as well as lower IgM Spike (p < 0.05) and RBD (p < 0.01) antibody levels. Conclusions The present study suggests that humoral response following SARS-CoV-2 infection does not appear to differ in pregnant women compared to their non-pregnant counterparts. These findings should reassure patients and healthcare providers that pregnant patients appear to mount a non-differential immune response to SARS-CoV-2.

The ViReflow pipeline enables user friendly large scale viral consensus genome reconstruction.

Throughout the COVID-19 pandemic, massive sequencing and data sharing efforts enabled the real-time surveillance of novel SARS-CoV-2 strains throughout the world, the results of which provided public health officials with actionable information to prevent the spread of the virus. However, with great sequencing comes great computation, and while cloud computing platforms bring high-performance computing directly into the hands of all who seek it, optimal design and configuration of a cloud compute cluster requires significant system administration expertise. We developed ViReflow, a user-friendly viral consensus sequence reconstruction pipeline enabling rapid analysis of viral sequence datasets leveraging Amazon Web Services (AWS) cloud compute resources and the Reflow system. ViReflow was developed specifically in response to the COVID-19 pandemic, but it is general to any viral pathogen. Importantly, when utilized with sufficient compute resources, ViReflow can trim, map, call variants, and call consensus sequences from amplicon sequence data from 1000 SARS-CoV-2 samples at 1000X depth in < 10 min, with no user intervention. ViReflow's simplicity, flexibility, and scalability make it an ideal tool for viral molecular epidemiological efforts.

Emergence of an early SARS-CoV-2 epidemic in the United States.

The emergence of the COVID-19 epidemic in the United States (U.S.) went largely undetected due to inadequate testing. New Orleans experienced one of the earliest and fastest accelerating outbreaks, coinciding with Mardi Gras. To gain insight into the emergence of SARS-CoV-2 in the U.S. and how large-scale events accelerate transmission, we sequenced SARS-CoV-2 genomes during the first wave of the COVID-19 epidemic in Louisiana. We show that SARS-CoV-2 in Louisiana had limited diversity compared to other U.S. states and that one introduction of SARS-CoV-2 led to almost all of the early transmission in Louisiana. By analyzing mobility and genomic data, we show that SARS-CoV-2 was already present in New Orleans before Mardi Gras, and the festival dramatically accelerated transmission. Our study provides an understanding of how superspreading during large-scale events played a key role during the early outbreak in the U.S. and can greatly accelerate epidemics.

Handwashing and Detergent Treatment Greatly Reduce SARS-CoV-2 Viral Load on Halloween Candy Handled by COVID-19 Patients.

Due to the COVID-19 pandemic and potential public health implications, we are publishing this peer-reviewed manuscript in its accepted form. The final, copyedited version of the paper will be available at a later date. Although SARS-CoV-2 is primarily transmitted by respiratory droplets and aerosols, transmission by fomites remains plausible. During Halloween, a major event for children in numerous countries, SARS-CoV-2 transmission risk via candy fomites worries many parents. To address this concern, we enrolled 10 recently diagnosed asymptomatic or mildly/moderately symptomatic COVID-19 patients to handle typical Halloween candy (pieces individually wrapped) under three conditions: normal handling with unwashed hands, deliberate coughing and extensive touching, and normal handling following handwashing. We then used a factorial design to subject the candies to two post-handling treatments: no washing (untreated) and household dishwashing detergent. We measured SARS-CoV-2 load by RT-qPCR and LAMP. From the candies not washed post-handling, we detected SARS-CoV-2 on 60% of candies that were deliberately coughed on, 60% of candies normally handled with unwashed hands, but only 10% of candies handled after hand washing. We found that treating candy with dishwashing detergent reduced SARS-CoV-2 load by 62.1% in comparison to untreated candy. Taken together, these results suggest that although the risk of transmission of SARS-CoV-2 by fomites is low even from known COVID-19 patients, viral RNA load can be reduced to near zero by the combination of handwashing by the infected patient and ≥1 minute detergent treatment after collection. We also found that the inexpensive and fast LAMP protocol was more than 80% concordant with RT-qPCR.IMPORTANCE The COVID-19 pandemic is leading to important tradeoffs between risk of SARS-CoV-2 transmission and mental health due to deprivation from normal activities, with these impacts being especially profound in children. Due to the ongoing pandemic, Halloween activities will be curtailed as a result of the concern that candy from strangers might act as fomites. Here we demonstrate that these risks can be mitigated by ensuring that prior to handling candy, the candy giver washes their hands, and by washing collected candy with household dishwashing detergent. Even in the most extreme case, with candy deliberately coughed on by known COVID-19 patients, viral load was reduced dramatically after washing with household detergent. We conclude that with reasonable precautions, even if followed only by either the candy giver or the candy recipient, the risk of viral transmission by this route is very low.