Coronavirus Disease 2019 Vaccine Booster Effects Are Seen in Human Milk Antibody Response

Infants remain at high risk for severe coronavirus disease 2019 (COVID-19). Human milk contains high levels of protective SARS CoV-2 specific antibodies post-infection and primary vaccine series, but levels decline over time. We hypothesized that the COVID-19 booster vaccine augment antibody production and the protection afforded to human milk-fed infants. We prospectively enrolled pregnant or lactating mothers planning to receive COVID-19 vaccination. We measured human milk IgG, IgA, and IgM antibodies targeting the SARS CoV-2 receptor binding domain within the spike protein and human milk neutralization activity against SARS CoV-2 in 10 lactating mothers from pre-COVID-19 primary series vaccine to post-booster dose. Human milk SARS CoV-2 specific IgG increased significantly from pre- to post-booster levels (median OD 0.33 vs. 2.02, P = 0.002). The IgG levels post-booster were even higher than the peak level after the primary series (2.02 vs. 0.95, P = 0.03). The increase in SARS CoV-2 specific IgA levels was not significant (0.10 vs. 0.33, P = 0.23). There was a strong correlation between paired maternal blood and milk IgG and IgA levels (IgG rho 0.52, P < 0.001, IgA rho 0.31, P = 0.05). Post-booster neutralizing activity was elevated compared to pre-booster levels (66% vs. 12% inhibition, P = 0.002). COVID-19 vaccine booster elicits SARS CoV-2 specific antibodies in human milk at higher levels compared to the initial primary series. This finding suggests that three doses of COVID-19 mRNA vaccination leads to improved mucosal response in human milk and reinforces current guidance recommending all pregnant or lactating mothers receive full COVID-19 vaccine courses with a booster dose.

High Prevalence of SARS-CoV-2 Genetic Variation and D614G Mutation in Pediatric Patients With COVID-19.

BACKGROUND: The full spectrum of the disease phenotype and viral genotype of coronavirus disease 2019 (COVID-19) have yet to be thoroughly explored in children. Here, we analyze the relationships between viral genetic variants and clinical characteristics in children. METHODS: Whole-genome sequencing was performed on respiratory specimens collected for all SARS-CoV-2-positive children (n = 141) between March 13 and June 16, 2020. Viral genetic variations across the SARS-CoV-2 genome were identified and investigated to evaluate genomic correlates of disease severity. RESULTS: Higher viral load was detected in symptomatic patients (P = .0007) and in children <5 years old (P = .0004). Genomic analysis revealed a mean pairwise difference of 10.8 single nucleotide variants (SNVs), and the majority (55.4%) of SNVs led to an amino acid change in the viral proteins. The D614G mutation in the spike protein was present in 99.3% of the isolates. The calculated viral mutational rate of 22.2 substitutions/year contrasts the 13.5 substitutions/year observed in California isolates without the D614G mutation. Phylogenetic clade 20C was associated with severe cases of COVID-19 (odds ratio, 6.95; P = .0467). Epidemiological investigation revealed major representation of 3 of 5 major Nextstrain clades (20A, 20B, and 20C) consistent with multiple introductions of SARS-CoV-2 in Southern California. CONCLUSIONS: Genomic evaluation demonstrated greater than expected genetic diversity, presence of the D614G mutation, increased mutation rate, and evidence of multiple introductions of SARS-CoV-2 into Southern California. Our findings suggest a possible association of phylogenetic clade 20C with severe disease, but small sample size precludes a definitive conclusion. Our study warrants larger and multi-institutional genomic evaluation and has implications for infection control practices.

Comparison of Upper Respiratory Viral Load Distributions in Asymptomatic and Symptomatic Children Diagnosed with SARS-CoV-2 Infection in Pediatric Hospital Testing Programs.

The distribution of upper respiratory viral loads (VL) in asymptomatic children infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is unknown. We assessed PCR cycle threshold (Ct) values and estimated VL in infected asymptomatic children diagnosed in nine pediatric hospital testing programs. Records for asymptomatic and symptomatic patients with positive clinical SARS-CoV-2 tests were reviewed. Ct values were (i) adjusted by centering each value around the institutional median Ct value from symptomatic children tested with that assay and (ii) converted to estimated VL (numbers of copies per milliliter) using internal or manufacturer data. Adjusted Ct values and estimated VL for asymptomatic versus symptomatic children (118 asymptomatic versus 197 symptomatic children aged 0 to 4 years, 79 asymptomatic versus 97 symptomatic children aged 5 to 9 years, 69 asymptomatic versus 75 symptomatic children aged 10 to 13 years, 73 asymptomatic versus 109 symptomatic children aged 14 to 17 years) were compared. The median adjusted Ct value for asymptomatic children was 10.3 cycles higher than for symptomatic children (P < 0.0001), and VL were 3 to 4 logs lower than for symptomatic children (P < 0.0001); differences were consistent (P < 0.0001) across all four age brackets. These differences were consistent across all institutions and by sex, ethnicity, and race. Asymptomatic children with diabetes (odds ratio [OR], 6.5; P = 0.01), a recent contact (OR, 2.3; P = 0.02), and testing for surveillance (OR, 2.7; P = 0.005) had higher estimated risks of having a Ct value in the lowest quartile than children without, while an immunocompromised status had no effect. Children with asymptomatic SARS-CoV-2 infection had lower levels of virus in their nasopharynx/oropharynx than symptomatic children, but the timing of infection relative to diagnosis likely impacted levels in asymptomatic children. Caution is recommended when choosing diagnostic tests for screening of asymptomatic children.

Shining a light on the pathogenicity of health care providers' mobile phones: Use of a novel ultraviolet-C wave disinfection device.

BACKGROUND: Mobile phones are known to carry pathogenic bacteria and viruses on their surfaces, posing a risk to healthcare providers (HCPs) and hospital infection prevention efforts. We utilize an Ultraviolet-C (UV-C) device to provide an effective method for mobile phone disinfection and survey HCPs about infection risk. METHODS: Environmental swabs were used to culture HCPs' personal mobile phone surfaces. Four cultures were obtained per phone: before and after the UV-C device's 30-second disinfecting cycle, at the beginning and end of a 12-hour shift. Surveys were administered to participants pre- and poststudy. RESULTS: Total bacterial colony forming units were reduced by 90.5% (P = .006) after one UV-C disinfection cycle, and by 99.9% (P = .004) after 2 cycles. Total pathogenic bacterial colony forming units were decreased by 98.2% (P = .038) after one and >99.99% (P = .037) after 2 disinfection cycles. All survey respondents were willing to use the UV-C device daily to weekly, finding it convenient and beneficial. DISCUSSION: This novel UV-C disinfecting device is effective in reducing pathogenic bacteria on mobile phones. HCPs would frequently use a phone disinfecting device to reduce infection risk. CONCLUSIONS: In light of the ongoing coronavirus (COVID-19) pandemic, a standardized approach to phone disinfection may be valuable in preventing healthcare-associated infections.