What was the seroprevalence of SARS-CoV-2 among US adults in 2021 and 2022?

recently Morbidity and Mortality Weekly Report (MMWR)the United States Centers for Disease Control and Prevention (US-CDC) has released preliminary results from the National Health and Nutrition Examination Survey (NHANES) for the period August 2021 through May 2022.

CDC has been monitoring the seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the US public since the beginning of the coronavirus disease 2019 (COVID-19) pandemic. They are seeking data on asymptomatic cases of COVID-19 that are likely undiagnosed and unreported.

Non-random sampling of data from blood donors from private diagnostic laboratories often influences serological estimates of SARS-CoV-2. On the contrary, NHANES will use his 2-year statistical sampling design to collect SARS-CoV-2 serology and self-reported her COVID-19 history and vaccination data from the US general population.

Background

Antibodies to the SARS-CoV-2 spike (S) and nucleocapsid (N) proteins indicate previous infection or vaccination and previous infection only, respectively. However, there are no data on what percentage of adults in the United States have acquired anti-SARS-CoV-2 antibodies through vaccination, previous infection, or both.

About research

In this study, researchers used NHANES data collected between August 2021 and May 2022 to quantify SARS-CoV-2 seropositivity in the US general population.

The team visited sequentially data from 15 primary sampling units collected during the 1-year data collection period, but was able to analyze initial data for adults aged 18 years and older from the first 10 units. The data show that his two girlfriends with SARS-CoV-2 Delta and the Omicron variant of concern (VOC) between August and November 2021 and December 2021 and May 2022. in response to each wave of COVID-19.

Researchers examined SARS-CoV-2 seroprevalence stratified by demographic characteristics such as age, gender, race, Hispanic origin, and educational attainment. In addition, they considered her self-reported COVID-19 and vaccination receipts (single or multiple vaccinations). They also assessed individual seroprevalence by combining anti-N-negative and anti-S-positive (vaccinated but not infected) and anti-S-positive and anti-N-positive test results (likely infected). estimated the rate.

Survey results

The NHANES serology data set included 1,574 participants aged 18 years and older during the 2-year study period. In the study cohort, 91.5% of her and 41.6% of her adults had SARS-CoV-2 anti-S and anti-N antibodies, respectively. The proportion of adults with documented anti-S-positive and anti-N-positive serology was 41.6% overall and decreased with age. Among young people aged 18 to 29, 59.7%, but only 30.2% among those aged 70 and over.

The overall proportion of vaccinated but uninfected US adults was 49.9%. This percentage increased among adults over the age of 70 over age 18-29, from 28.1% to 64.7% for him. However, it remained consistently lower among Hispanics and Blacks and those who did not attend high school at 35.3%, 46.7% and 42.5% respectively. However, the rates were also higher among white adults and college-educated adults, at 58.9% and 55.4%, respectively.

Serological results of 655 study participants showed infection, but 43.7% reported never having had COVID-19, suggesting asymptomatic infection. were mostly from black adults and those who did not attend high school.

Among infected but potentially vaccinated adults, 25.5% self-reported not to have been vaccinated against COVID-19. Despite serologic evidence of infection, 31.3% of black adults and 21.4% of Hispanic adults self-reported that they had not been vaccinated against COVID-19. Clearly, these ethnic groups acquired anti-S-positive and anti-N-positive antibodies through infection rather than vaccination.

Conclusion

In summary, serological testing of US adults found that up to 42% had SARS-CoV-2 antibodies likely due to exposure to SARS-CoV-2, Nearly 44% self-reported never had COVID-19. Limited access to COVID-19 testing may have amplified undiagnosed SARS-CoV-2 infections among younger and black Americans. This resulted in disparities in community transmission, infection rates and outcomes. Overall, these results raise concerns about public health equity.

Based on its findings, the CDC recommends that all Americans be vaccinated against COVID-19. In addition, they argued, efforts should continue to achieve equity in primary vaccination and booster dose coverage.