People who were already pregnant at the start of the COVID-19 pandemic had a 50% lower exposure to SARS-CoV-2 compared to those who became pregnant after the start of the pandemic and the population general, according to a new model created by Weill Cornell. Researchers in Medicine, NewYork-Presbyterian and the University of Oxford.
The findings, published Oct. 30 in the journal Virus, are some of the most extensive data to support the common idea that protective measures such as masking, social distancing and quarantine conferred a significant protection to pregnant people during the first months of the pandemic.
New York City was the epicenter of the COVID-19 pandemic in March 2020. Public health authorities and medical professionals recommended protective measures for protection against SARS-CoV-2 infection , especially for vulnerable populations, recommendations that continue today. Although the effects of COVID-19 on pregnant women were not well understood at the time, it is now known that they are at increased risk of severe illness, ICU admission with mechanical ventilation, and death from COVID-19 .
“While we can only infer that pregnant people followed public health recommendations and protected themselves with protective measures during the early months of the pandemic (since SARS-CoV-2 vaccines were not yet available), this is evidence that these protective measures against a largely unknown infectious disease threat were remarkably successful,” said co-author Dr. Nathaniel Hupert, associate professor of population health sciences at Weill Cornell Medicine and internist at NewYork-Presbyterian/Weill Cornell Medical Center.
All pregnant people admitted to NewYork-Presbyterian/Weill Cornell Medical Center to deliver babies in April 2020 received the RT PCR test, which analyzes nasal or oropharyngeal swab samples to determine whether a person is infected with SARS- CoV-2. After initial studies showed that certain people were infected but had no symptoms, Weill Cornell Medicine researchers realized that RT PCR tests alone did not represent the actual number of individuals exposed to the virus. The addition of serological tests to the blood allowed the detection of antibodies with the ability to bind to the spike protein of the virus, indicating a previous infection.
“We found it essential to capture the entire spectrum of patients exposed to the virus, so that we can follow them long-term to understand the repercussions of infection during pregnancy,” said lead author Dr. Yawei Jenny Yang, assistant professor of pathology. and laboratory medicine at Weill Cornell Medicine and pathologist at NewYork-Presbyterian/Weill Cornell Medical Center. “Our data set was rare in that we had data for a large and consistent patient population with both RT PCR and serology test results over a long period. This consistency allowed us to infer exposure to SARS-CoV- 2 in a vulnerable patient population.”
Dr. Hupert, who in March 2020 established the International COVID-19 Modeling Consortium with infectious disease modeling collaborators at the University of Oxford and other international institutions, recalls being struck by the immense value of the set of data from Dr. Yang. “Bringing together this unique longitudinal data, carefully curated with the modeling expertise of the University of Oxford was very fortunate,” he said.
For their analysis, the researchers estimated exposure rate measurements from 2,196 pregnant women who gave birth at NewYork-Presbyterian/Weill Cornell Medical Center from April 2020 to December 2020 and compare with data from the general population of New York City. The researchers determined that pregnant people’s exposure to SARS-CoV-2 was 50 percent lower than that of the general population at the start of the pandemic, but rose to match the level of the general population during the following nine months.
“This increase in exposure makes sense, as the data reflect an increasing number of individuals who had been exposed to SARS-CoV-2 before becoming pregnant,” explained Dr. Hupert.
“Our research demonstrates the value of building models to learn how changes in behavioral patterns affected exposure to SARS-CoV-2 in a large population of vulnerable individuals,” said Dr. Yang. “Many thanks to our collaborators at Weill Cornell Medicine, Cornell University, NewYork-Presbyterian/Weill Cornell Medical Center and the University of Oxford.”
/ Public communication. This material from the original organization/author(s) may be ad hoc in nature, edited for clarity, style and length. The views and opinions expressed are those of the author(s). See them in full here.