Covid-19 immunity appears to be gaining strength with more time between vaccination and infection, suggests a new lab study from Oregon Health & Science University researchers. The findings have implications for vaccine recommendations as the pandemic transitions to an endemic state.
the researchers measured the antibody response in blood samples from a group of people who obtained the so-called “hybrid immunity” through two means: vaccination followed by advanced infection or getting vaccinated after contracting COVID-19. They measured the immune response in blood samples from 96 generally healthy OHSU employees and found that the immune response was consistently stronger the longer the time period between vaccination and infection. The longest interval measured was 404 days.
Their findings suggest that vaccine boosters should not be spaced more than a year apart, at least among healthy people. “Longer intervals between natural infection and vaccination appear to strengthen the immune response of healthy people,” said co-lead author Fikadu Tafesse, Ph.D. associate professor of molecular microbiology and immunology at the OHSU School of Medicine.
The study occurs when and advisory panel from the Food and Drug Administration (FDA) will meet on Thursday, January 26 to consider the progress of the strategy national vaccination against Covid-19. Published in the Journal for Clinical Investigation Insightthe new research is the latest in a series of laboratory discoveries by OHSU scientists that reveal a pattern of immune response strengthened through hybrid immunity. Their findings suggest that the magnitude, potency, and breadth of the hybrid immune response increased with a longer period of time between exposure to the virus, either through vaccination or natural infection.
Not all terrains in the world have such large gaps in the geologic record, and previous LPME studies have focused primarily on reservoirs in the Northern Hemisphere. However, the Sydney Basin in eastern Australia and the Karoo Basin in South Africa are two areas in the southern hemisphere with excellent records of the phenomenon and which the study authors had previously studied.
Frank, Fielding, and other co-authors were contacted by a colleague and co-author, Jun Shen, from the State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences. to obtain samples and analyze them for isotopes of mercury. According to Frank, Shen was able to analyze the mercury isotopes in the samples and match all the data.
This is likely related to the maturation of the body’s immune response over time, said the co-senior author. Marcel Curlin, MD Associate Professor of Medicine (Infectious Diseases) at the OHSU School of Medicine and OHSU Medical Director of Occupational Health.
“The immune system is learning,” Curlin said. “If you are going to amplify a response, what this study tells us is that you may want to boost that response after a longer period of learning rather than shortly after exposure.”
Furthermore, the research team found that it did not matter whether someone developed hybrid immunity from being vaccinated after contracting Covid-19 or after advanced infection after vaccination.. Both groups developed an equally potent immune response.
The findings suggest a lasting power of so-called “memory cells,” the B cells that recognize an invading virus and generate protein antibodies to neutralize the virus and its many variants. The authors write that a growing group of people who have contracted the SARS-CoV-2 virus will benefit from vaccination, even if they have delayed it until now.
Relying only on natural infection is a bad idea,”given the risks of severe disease, long-term complications, and death,” the authors write. In addition, the researchers say the findings are the latest to signal that the virus is evolving towards an endemic state.
Our results point to a future in which unavoidable vaccine breakthrough infections would be expected to help build a population-level reservoir of immunity that can help mitigate future waves and reduce the opportunity for further viral evolution. . Finally, the researchers noted that the immune response was measured in relatively healthy people, and that boosters may be recommended more frequently among vulnerable people who are older or immunocompromised.