Vaccine response: Scientists say the secret may already be in your blood
Published on 24/08/2026 - 13:05 GMT+2•Updated 13:12 Not everyone reacts to vaccines in the same way....
Published on 24/08/2026 - 13:05 GMT+2•Updated 13:12
Not everyone reacts to vaccines in the same way. Immune responses vary in strength depending on age, sex, prior illnesses and genetics.
In a new study, published in the Cell Press Blue journal, researchers at the United States National Cancer Institute’s SeroNet program investigated how pre-existing antibodies to common microbes can predict a person’s response to new vaccines.
“Certain biomarkers, when analyzed with AI, can predict who is likely to respond well to a vaccine, even before they receive it,” said Joshua LaBaer, who led the study, which suggests that some people may be more immune-ready than others.
Immunosuppression — having a weak immune system — is associated with a weaker antibody response to vaccination, which increases the risk of infection, disease severity and mortality.
The researchers found that, before receiving a vaccine, the body’s immune system already hints at how it will react and how robust the response will be.
The study analysed over 8,000 blood samples from more than 4,000 people, testing for antibodies against 185 antigens from common viruses, bacteria and autoimmune-linked targets.
Participants included healthy volunteers as well as people with weakened immune systems — due to conditions such as HIV, multiple myeloma and solid organ transplantation — all of whom received the COVID-19 vaccine.
The researchers then used artificial intelligence to analyse patterns in samples collected before and after COVID-19 vaccination, identifying antibody signatures that helped categorise patients as either strong or poor vaccine responders.
They identified what they call "sentinel antibodies," which act as indicators of a person’s likely immune response to a given vaccine, helping predict how an individual’s body will react to the virus.
“We identified universal antimicrobial signatures that were positively associated with the top 25% of high COVID-19 vaccine responders,” the researchers noted.
The study found that higher levels of certain pre-existing antibodies, especially those against common organisms such as Staphylococcus aureus, Respiratory Syncytial Virus (RSV) and human parainfluenza virus 3 (HPIV-3), were associated with stronger COVID-19 vaccine responses.
Transforming vaccination strategies
By using pre-existing antimicrobial antibody profiles as predictive biomarkers, clinicians could identify individuals likely to develop a weak immune response before they are immunised.
The study applied machine learning to construct predictive models to classify individuals with suboptimal vaccine response.
“Predicting which individuals will mount poor antibody responses before vaccination could improve personalised vaccination strategies,” the researchers wrote.
This would allow for targeted interventions such as tailored dosing schedules, different vaccine types or additional booster requirements for those at higher risk.
