Shadow of a Pandemic: Persistence of Prenatal SARS-CoV-2 Antibodies in Newborn Blood Spots

• Published in: International journal of neonatal screening Vol. 9; no. 3; p. 43
• Main Authors: Sciortino, Stanley, Graham, Steve, Fillman, Toki, Kandasamy, Hari, Cooley, Robin, Hanson, Carl, Eckert, Valorie, Tang, Hao, Yang, Juan, Seftel, David, Tsai, Cheng-ting, Robinson, Peter
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 02.08.2023; MDPI
• Subjects: Age; Antibodies; antibody testing; Babies; Binomial distribution; Biobanks; Births; Blood banks; COVID-19; Demography; dried blood spots; Ethnicity; Health aspects; Hispanic people; Infants (Newborn); Infection; Infections; Laboratories; Medical screening; newborn; Newborn babies; newborn screening; Pandemics; positive predictive value; Postal codes; Pregnancy; Pregnant women; Serology; Severe acute respiratory syndrome coronavirus 2; Viral antibodies; Womens health; California; United States > US
• ISSN: 2409-515X; 2409-515X
• DOI: 10.3390/ijns9030043

To investigate COVID-19 surveillance among pregnant women, the California Genetic Disease Screening Program conducted a screening performance and seroprevalence evaluation of maternal SARS-CoV-2 antibodies detected in banked newborn dried blood spots (DBS). We obtained seropositive results for 2890 newborn DBS from cohorts in 2020 and 2021 using Enable Bioscience’s Antibody Detection by Agglutination-PCR (ADAP) assay for SARS-CoV-2 antibodies. To infer maternal infection, we linked 312 women with a known laboratory-confirmed COVID-19 episode with their newborn’s DBS SARS-CoV-2 antibody result. Among 2890 newborns, we detected 453 (15.7%) with SARS-CoV-2 antibodies in their DBS. Monthly snapshot statewide seroprevalence among neonates was 12.2% (95% CI 10.3–14.1%, n =1156) in December 2020 and 33.3% (95% CI 29.1–37.4%, n = 26) in March 2021. The longest time recorded from COVID-19 infection to a seropositive neonatal result was 11.7 months among the 312 mothers who had an available SARS-CoV-2 PCR test result. Approximately 94% (153/163) of DBS were seropositive when a known maternal infection occurred earlier than 19 days before birth. The estimated relative sensitivity of DBS to identify prevalent maternal infection was 85.1%, specificity 98.5% and PPV 99.2% (n = 312); the sensitivity was lowest during the December 2021 surge when many infections occurred within 19 days of birth. Fifty pre-pandemic specimens (100% seronegative) and 23 twin-pair results (100% concordant) support an intrinsic specificity and PPV of ADAP approaching 100%. Maternal infection surveillance is limited by a time lag prior to delivery, especially during pandemic surges.