The rapid spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the United States has extended healthcare computing beyond its limits. This is mainly due to the increasing demand for in-depth real-time information on viral load and antibody responses across the country.
This challenge was further complicated by the lack of accurate and timely evidence that was available in the United States at the beginning of the pandemic. In fact, SARS-CoV-2 testing was largely performed in response to suspected infection, rather than proactively. Antibody testing was also rarely performed.
In a recent study published on the prepress server medRxiv,* Researchers attempted to monitor immunoglobulin G (IgG) levels against SARS-CoV-2 in populations undergoing routine testing. In addition, the authors correlated these serum levels with infection, vaccination, and available demographic data.
To study: Comparison of antibody levels in response to SARS-CoV-2 infection and vaccination type in a midwest cohort. Image credit: vitstudio / Shutterstock.com
About the study
The current study included 245 individuals, of whom 135 were women and 110 were men. A total of 19 participants had received the Johnson & Johnson (J&J) 2019 single-dose coronavirus disease vaccine (COVID-19), while 141 and 72 had received the Pfizer and Modern messenger ribonucleic acid (mRNA) vaccines. ) of two doses, respectively.
It should be noted that 12 participants had not received any vaccine. A total of 43 participants had a previous infection with COVID-19, with 3 asymptomatic individuals.
Blood samples were collected from all participants. Enzyme-based immunosorbent assay (ELISA) assessment was performed on blood samples once a month for a total of eleven months to determine levels of anti-SARS-CoV-2 antibodies in the blood.
The study included certain biases, such as economic, cohort, and racial educational bias.
Study results
Current results indicate that antibody levels in unvaccinated individuals after infection extended up to ten months after infection. In addition, patient responses to Pfizer, Moderna, and J&J vaccines were clearly observed ten days after vaccination. However, more consistent antibody levels were observed twenty days after vaccination.
Individuals who had received the J&J vaccine had lower antibody levels compared to the other two vaccines, both in naïve and recovered individuals. Thus, it can be concluded that the efficacy of the J&J vaccine was lower than the Pfizer and Moderna vaccines.
After vaccination with Pfizer or Moderna vaccines, antibody responses peaked within 40 days of vaccination, and levels began to decline after 120 days. Further testing will be needed to determine whether antibody response levels continue to decline or remain at a level similar to recovered individuals. The study also showed that the antibody response for all three vaccines was superior in recovered individuals compared to naïve individuals.
Anti-SARS-CoV-2 (IgG) antibody signals from samples of naïve and recovered individuals receiving vaccines from different manufacturers compared to unvaccinated individuals with positive PCR (data reproduced from Fig. 1). The numbers of replicas collected independently are (right to left) 46, 122, 331, 8, 40, 31, and 133. Samples collected by individual are shown in Figure S4.
“We observed little in relation to demographic impacts on antibody production, with only one gender affecting infection recovery and no impact of gender, age, or race on responses to Pfizer and Moderna vaccines.”
Comparison of female and male anti-SARS-CoV-2 Spike (IgG) signals. N refers to the number of independent replicas. The vaccinated group is only Pfizer and Moderna, as other groups of manufacturers did not get the necessary figures for statistical comparison.
The study had certain limitations, including the binding of IgG to a single spike isoform, uncertainty in the method and timing of sample collection, as well as participants who belonged only to a local community.
* Important news
medRxiv publishes preliminary scientific reports that are not peer-reviewed and therefore should not be considered conclusive, guide clinical practice / health-related behavior, or treated as established information.