Researchers Say Pfizer COVID-19 Vaccine May Reprogram Innate Immune Response
The Pfizer-BioNTech COVID-19 vaccine is very effective in giving protection
However, a research team warned that this product may induce complex reprogramming of the innate immune system
Thus, they proposed consideration of this aspect in the development and use of mRNA-based vaccines
The research was led by major institutions in Germany and the Netherlands, including Radboud University Medical Center and Helmholtz-Centre for Infection Research
Researchers investigated more than what the vaccine could do against SARS-CoV-2 and its variants
They went beyond and analyzed if the drug could affect the immune system in the long run, according to News-Medical.net
First, they tested how the vaccine performed against the UK and South African variants
A single dose of the Pfizer vaccine resulted in high levels of antibodies against the spike of the virus
The second dose further increased these levels
Tested samples were effective in neutralizing the UK variant, yet were 37.5% less effective against the South African variant
This suggested that the latter could escape vaccine-induced immune response to a certain degree
Next, they studied the vaccine’s performance on cellular response
Reports showed that it could activate SARS-CoV-2-specific CD4+ and CD8+ T cells, and also increase immune-modulatory cytokines like interferon-y (IFN-y)
Researchers assess the IFN-y secretion in response to SARS-CoV-2 variants before and after vaccination
The vaccine increased the production by at least 50% in 37.5% of samples stimulated using the original virus strain and in 50% stimulated with the UK or South African variant
Yet only 18.8% of samples stimulated with the Bavarian variant exhibited increased production
The latter is a new variant detected in Bavaria, Germany earlier this year
Despite the boosted response against SARS-CoV-2, the vaccine might have changed certain functions of the immune system
The vaccine reduced the production of pro-inflammatory cytokines tumor necrosis factor-alpha and interleukin-1beta
The former regulates proper growth and differentiation of cell types and the latter is a key mediator of inflammatory response
Their findings suggested that some aspects of the immune system may be altered, though the alteration could not be confirmed if permanent or otherwise
Researchers concluded that enhancing adaptive immune response to boost antibody production may either lead to a more balanced inflammatory reaction to the coronavirus or weaken innate immunity
If the latter is true, the vaccine may also interfere with responses to other vaccines
The paper was uploaded on MedRxiv and is yet to be peer-reviewed