A team from the Carlos III Health Institute (ISCIII) has published an article in Journal of Medical Virology revealing the results of an investigation into the effects of SARS-CoV-2 infection on the development of humoral immunitythat is, that generated by antibodies.
The study analyzes the immune response against different variants of the coronavirus, including omicron, in people vaccinated against covid-19. His conclusions suggest that a mechanism of maturation of neutralizing antibodies —one of the defenses of the immune system— can have the positive effect of separating vaccination for a certain time after a natural infection.
The research is led by ISCIII, specifically from the AIDS Serology and Immunopathology Units of the National Center for Microbiology (CNM). The authors, as explained Francisco Diez Fuerteshighlight the interest of studying the so-called hybrid immunity, which includes the immune response generated against natural infection and that developed by vaccination. The combination of both immune responses has been studied in 66 doctors, nurses and other healthcare workers at the Puerta de Hierro Hospital in Majadahonda (Madrid).
The study highlights the interest of hybrid immunity, which includes the immune response generated against natural infection and that developed by vaccination
Half of the participants had not had a previous infection at the time that mass vaccinations against SARS-CoV-2 began in Spain, at the beginning of 2021.
The other half had been diagnosed with SARS-CoV-2 infection by PCR, with a relevant difference: 14 of them were infected during the first 10 months of the epidemic in 2020, while another 17 had been infected in the three months prior to receiving the first dose of the vaccine, between November 2020 and January 2021. All received two doses of the mRNA-1273 (Modern) vaccine 28 days apart; the authors collected blood samples from the 66 participants for analysis at 0, 28, and 42 days after the first dose.
The investigation confirms the beneficial effect of hybrid immunity, which manages to increase between 2.3 and 3.3 times the neutralizing immune response against variants such as alpha, beta or delta. This increase is especially significant compared to the omicron variant, since it increases this immune system response up to 4.5 times.
This type of immunity manages to increase between 2.3 and 3.3 times the neutralizing immune response against variants such as alpha, beta or delta. The magnification is 4.5 times in the case of omicron
More than three months interval
Javier Garcia Perez, the main author of the article, points out that one of the most important results of the study has made it possible to verify the effect of vaccinating more than three months after a natural infection has occurred, which allows an increase of between 2.2 and 2.8 times in the titers of neutralizing antibodies against the main variants of the coronavirus. This fact could be explained, according to the authors, by the need for a minimum amount of time to elapse —the aforementioned 3 months— for a evolution of neutralizing antibodiess in the so-called germinal centers, where B cells persistently recognize virus antigens trapped in follicular dendritic cells.
The work has been possible thanks to the close collaboration that the ISCIII AIDS Serology and Immunopathology units have maintained since the beginning of the coronavirus epidemic in Spain, with the aim of responding to different aspects related to immunity against SARS. -CoV-2. As a result of this collaboration, other works have been published like the CombiVacsrelated to heterologous vaccination regimens; RescueVacson revaccination in subjects who had previously received an unauthorized experimental vaccine, and the ENE-COVID-Senior studyon immunity in the elderly.
Reference
Javier García Pérez et al. “Longer intervals between SARS-CoV-2 infection and mRNA-1273 doses improve the neutralization of different variants of concern“. Journal of Medical Virology (2023).
Rights: Creative Commons.
