United States: It was especially puzzling for people to require an annual flu vaccine, though they carry some long-term immunizations received in childhood to shield them from measles and mumps.
Research is getting closer to explaining why vaccine effectiveness differs – and they have found a way to test how long a vaccine lasts in our body, as reported by HealthDay.
Why Do Some Vaccines Last Longer?
“Our study defines a molecular signature in the blood, induced within a few days of vaccination, that predicts the durability of vaccine responses and provides insights into the fundamental mechanisms underlying vaccine durability,” senior researcher Bali Pulendran, a professor of microbiology and immunology with Stanford Medicine, said in a news release from the college.
Hossein Gholizadeh Sedigh, a biostatistician in Iran, said this test could help develop a tactic for the individualization of vaccines and determine how and when some boosters will be necessary earlier than others.
“Why some vaccines are able to stimulate long-term levels of antibodies that can persist for decades, while others may only offer protection for a few months at best – that’s been one of the biggest questions in questions in terms of vaccine log chemistry or science,” Pulendran pointed out.
And guess what? It has a lot to do with a blood cell called megakaryocytes, which is known for clotting, research published in the Nature Immunology journal on January 2 shows.
Testing Vaccine Longevity
In the research, 50 individuals who were given an experimental H5N1 bird flu vaccine were observed by the researchers.
The patients were then randomized and divided into two groups: those were to be vaccinated alone and those to be vaccinated with an adjuvant – a substance used to boost the immune response to a vaccine.
Twelve blood points were obtained from the subjects daily for the first one hundred days after being vaccinated, and blood samples were then used to survey every single gene and protein, as well as the antibodies in action, throughout the process of the immune response.
This means that when blood samples were tested, the chronicles pointed out the strength of a person’s antibodies months after the administration of the vaccine.
This pattern was primarily evident in DNA found in their platelets- the tiny cells responsible for forming clots in blood.
Platelets originate from mega karyocytes in the bone marrow, the researchers explained. They are launched into the blood circulation from megakaryocytes and therefore contain fragments of the genetic material of the greater cells.
“What we learned was that the platelets are a bellwether for what is happening with megakaryocytes in the bone marrow,” Pulendran said.
To confirm that megakaryocytes were in any way associated with vaccine longevity, the researchers injected laboratory mice with the bird flu vaccine plus thrombopoetin. That drug increases the count of activated megakaryocytes in the bone marrow.
Surprisingly, thrombopoetin boosted levels of anti-bird flu antibodies 6 times in 2 months, according to the researchers.
Subsequent studies showed that megakaryocytes secrete substances that enhance the lifespan of the bone marrow cells for making antibodies.
“Our hypothesis is that megakaryocytes are providing this nurturing, pro-survival environment in the bone marrow for plasma (immune) cells,” Pulendran said.
Broader Implications Across Vaccines
In order to find out whether this was so for other types of vaccines, information from other studies assessing almost 250 participants receiving seven various types of vaccines, including the seasonal flu, yellow fever, malaria, and COVID-19, was examined.
There was also increased activation of megakaryocytes, and Schmolke and Reid published these results along with the rest of the study, revealing that all seven of the vaccines tested had longer-lasting antibody production.
Thus, the signature could tell which of the vaccines had a longer immunity and which people would have a longer immune reaction.
“The predictive power of the platelet-associated signature appeared to hold true across a diverse range of vaccines, suggestive of the existence of a conserved mechanism underlying vaccine durability,” Dr. Petter Brodin, a pediatrician with the Karolinska Institute in Sweden, wrote in an editorial accompanying the new study.
“This raises the tantalizing prospect of developing a practical tool for predicting the longevity of immune responses during vaccine development and clinical trials,” Brodin continued.
The research team would like to continue more research that would establish the reason as to why some vaccines cause increased activation of megakaryocyte. These types of knowledge would help advance stronger and longer-lasting vaccines.
Toward Personalized Vaccination Plans
They also want to come up with tests on how long it would take before the vaccine stops being effective, which would lead to the formation of vaccine plans for each individual, as reported by HealthDay.
“We could develop a simple PCR assay — a vaccine chip — that measures gene expression levels in the blood just a few days after someone is vaccinated,” Pulendran said. “This could help us identify who may need a booster and when.”