In a recent study published on the medRxiv * prepress server, researchers evaluated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which neutralizes antibody activity among migrant workers.
Study: SARS-CoV-2 neutralizing antibody activity in a highly vaccinated population: Longitudinal serology studies in Singapore. Image credit: Kateryna Kon / Shutterstock
The decline in protection induced by natural infection and coronavirus disease vaccines 2019 (COVID-19) has raised major concerns about public health policies. In addition, there is still a lack of data on the duration and potency of immune responses to vaccines, as well as natural infections.
About the study
In the present study, researchers investigated COVID-19 infection rates and SARS-CoV-2 immune responses among a migrant population over a six-week period.
The study included a test cohort of migrant workers between the ages of 19 and 59 who were residents in a dormitory infected with COVID-19. The team obtained blood samples from participants in May 2020, as well as two to six weeks after the initial sampling. The community cohort included adults living in the community 21 years of age or older who also provided blood samples in November or December 2020.
The team analyzed the serological samples obtained to detect the presence of SARS-CoV-2 neutralizing antibodies using a substitute virus neutralization test (sVNT). Information related to the presence or incidence of other medical problems such as diabetes, heart disease, and hypertension, along with data related to the number, type, and dates of COVID-19 vaccines received.
The researchers performed serological analysis of participants who reported receiving two doses of any COVID-19 messenger ribonucleic acid (mRNA) vaccine in May or June 2021. The cohort of the study also included individuals who had received two and three vaccines against COVID-19. dose before January 2022. For people vaccinated with two or three doses, the team compared the neutralizing activity of SARS-CoV-2 based on the type of vaccine administered.
In addition, the team evaluated the cumulative distribution of SARS-CoV-2 neutralizing activity based on time point, as well as the number of doses of COVID-19 vaccine received by various populations, taking into account factors such as age, gender, and pre-existing comorbidities. . Neutralizing activity decay rates were also assessed for individuals who had received two to three doses of mRNA vaccine. The team also compared neutralizing antibody activity between vaccines belonging to the community cohort and those with mild or asymptomatic COVID-19 infection.
Results
A total of 799 individual vaccinations, including 553 comirnaty, 131 Spikevax and 115 mixed doses of Spikevax and Comirnaty. The team noted that the second dose of vaccine was received after an average duration of 27 days until follow-up in May or June 2021 and 157 days at follow-up in January 2022. The results of the study showed that people who received the Spikevax vaccine had noticeably higher levels of neutralizing antibody activity after both doses. However, among the three-dose receptors, high levels of neutralizing antibodies were found for all vaccines analyzed with single-dose and mixed-dose vaccines that showed comparable neutralizing activity.
When the team made comparisons based on cumulative distributions, individuals 70 years of age or older had lower neutralizing activity after receiving two doses until May or June 2021. However, in January 2022, all age groups they showed lower and comparable levels of neutralization. antibodies. This indicated that although younger participants had elevated levels of neutralizing antibodies initially after vaccination, levels of protection decreased to similar levels over time. In particular, neutralizing activity was significantly higher at three-dose receptors compared to two-dose receptors.
The team observed higher neutralizing antibody responses after two doses among women in May or June 2021, which were finally reduced to levels comparable to men in January 2022. of booster vaccine increased neutralizing antibody responses to substantially higher levels with negligible levels. differences between the two genders. In addition, people with hypertension and diabetes had lower neutralizing antibody responses after two doses in May or June 2021 compared to people who did not have comorbidities.
The team also observed that men 60 years of age or older who belonged to the general population group and had received two or three doses of vaccine during the previous 12 weeks showed higher neutralizing antibody responses compared to the cases. mild or asymptomatic infected with COVID-19. men of the migrant cohort. In addition, the team noted that 84% of unvaccinated individuals had anti-SARS-CoV-2 neutralizing antibodies, indicating a substantial impact of the natural infection in the previous six or seven months.
Conclusion
Overall, the results of the study showed that booster doses of COVID-19 had a potent effect in providing sufficient protection against SARS-CoV-2 infection. Researchers believe that the rise in cases of innovative infection requires the development of a specific COVID-19 vaccine for SARS-CoV-2 variants.
* Important news
medRxiv publishes preliminary scientific reports that are not peer-reviewed and therefore should not be considered conclusive, guided by clinical practice or health-related behavior, or treated as established information.