by wayne persky |
RSS Feed Compared with common vaccines such as those for tetanus and influenza, the protective effects of COVID-19 mRNA vaccines decline relatively quickly. Recently published research offers some insights into the immune mechanisms involved, to help explain why the vaccines are so short-lived (Nguyen, et al., 2024).1 And as a National Institutes of Health (NIH) article points out, even an actual Covid 19 infection does not confer long-lasting immunity (Contie, 2024, October 29).2
This is very likely the main reason why so many people have had multiple Covid infections. The persistence of the virus to generate new variations of the disease relatively quickly surely adds to the risk of infection (and reinfection), but if the immune system was capable of generating a robust and longer-lasting immune response, the vaccines (or an actual Covid infection) would provide much longer-lasting protection.
This is very likely the main reason why so many people have had multiple Covid infections. The persistence of the virus to generate new variations of the disease relatively quickly surely adds to the risk of infection (and reinfection), but if the immune system was capable of generating a robust and longer-lasting immune response, the vaccines (or an actual Covid infection) would provide much longer-lasting protection.
Long-lasting immunity requires long-lived plasma cells (LL PCs).
LLPCs in the bone marrow can produce antibodies over extended periods, possibly for decades. Effective vaccines, like those used for tetanus and influenza, successfully generate LLPCs that establish themselves in the bone marrow and provide sustained antibody protection.
mRNA COVID-19 vaccines generate high levels of short-lived antibody secreting cells, but fail to establish LLPCs in the bone marrow. SARS-CoV-2 antibody levels decline within 3-6 months after vaccination, leading to reduced protection over time.
mRNA COVID-19 vaccines generate high levels of short-lived antibody secreting cells, but fail to establish LLPCs in the bone marrow. SARS-CoV-2 antibody levels decline within 3-6 months after vaccination, leading to reduced protection over time.
An apparent paradox exists.
SARS-CoV-2-specific plasma cells are detectable in the bone marrow but fail to transition into long-lived compartments. This raises questions about whether the issue lies in the nature of the spike protein, the vaccine delivery method, or other immune signaling factors.
Does the problem originate with the SARS-CoV-2 spike protein?
The spatial arrangement is less effective at cross-linking B-cell receptors compared with other viral proteins, such as those from influenza or tetanus. Cross-linking of B-cell receptors is essential for robust activation of B cells and their maturation into LLPCs.
Or does the problem originate with the mRNA platform?
It's unclear whether the rapid waning of antibody responses is specific to the SARS-CoV-2 spike protein or a limitation of the mRNA platform itself. Comparisons with other mRNA vaccines, like those for RSV, may help determine if the platform inherently hinders LLPC formation.
Despite their relatively short-lived umbrella of protection,
mRNA vaccines are the best option we have available for preventing the debilitating effects of Long Covid, and the life-threatening risks that are associated with the virus, and these vaccines have saved tens of millions of lives over the past few years.
Currently, frequent booster shots are needed in order to maintain protection.
Due to the short-lived protection provided by current mRNA COVID-19 vaccines, booster shots are required to maintain immunity. Boosters temporarily increase antibody levels, but may not address the underlying inability to establish LLPCs, necessitating ongoing research for more durable solutions. Hopefully, future research will allow the development of vaccines with longer-lasting effectiveness against the risks of the Covid 19 variants.
References
1. Nguyen, D. C., Hentenaar, I. T., Morrison-Porter, A., Solano, D., Haddad, N. S., Castrillon, C., . . . Lee, F.E. (2024). SARS-CoV-2-specific plasma cells are not durably established in the bone marrow long-lived compartment after mRNA vaccination. Nature Medicine, Retrieved from https://pubmed.ncbi.nlm.nih.gov/39333316/
2. Contie, V. (2024, October 29). Why protective antibodies fade after COVID-19 vaccines. National Institutes of Health, Retrieved from https://www.nih.gov/news-events/nih-research-matters/why-protective-antibodies-fade-after-covid-19-vaccines
