A new study has shown up to a four-fold increase in immune response when switching arms for multi-dose vaccines such as the Covid-19 vaccine. The findings, from a study of 947 participants and published in the Journal of Clinical Investigation, challenge assumptions that arm selection does not affect vaccine efficacy, and have implications for improving vaccine efficacy in variables such as Omicron.
The discovery of a vaccine for Covid-19 could shape clinical practice worldwide.
New research shows that when people switch from one arm to the other when they receive a large dose of the vaccine, the immune response increases fourfold.
The laboratory study, led by researchers at Oregon Health & Science University, measured antibody responses in 947 people who received two doses of the vaccine. covid 19 At the beginning of the epidemic. Participants included OHSU employees who agreed to be enrolled in research at the time of vaccination SARS-CoV-2 Virusand were randomized to receive the second dose at the same or opposite arm as the first.
The study was recently published in Journal of Clinical Investigation.
Historically, clinicians have assumed that hand selection does not matter.
The new study tested serum samples collected at different times after vaccination. They found a significant increase in the size and breadth of the antibody response compared to those who had “a shot in each arm” or a shot in each arm.
The improved response was clearly seen three weeks after the second boost and lasted more than 13 months after supplementation. Investigators boosted immunity to the original SARS-CoV-2 strain, and found a stronger immune response to the Omicron variant seen one year after the arm switch.
Researchers aren’t sure why this happens, but they think that giving a shot in each arm activates new immune responses in different lymph nodes in each arm.
Marcel Curlin, MD, associate professor of medicine (infectious diseases) at the OHSU School of Medicine and associate professor of medicine at the OHSU School of Medicine and OHSU Occupational Health Director, says, “By switching hands, you’re going to notice two places instead of one. You have a formation.”
Laboratory research produces eye-opening results
OHSU had the opportunity to examine blood drawn from volunteers early in the Covid-19 outbreak as part of a series of laboratory studies. That line of research has produced a series of published studies dealing with the intensity, breadth, and strength of the immune response following vaccination and infection.
After vaccines became available in late 2020, some participants thought it would have made a difference if they switched arms in the two-dose period.
“This question hasn’t really been studied extensively, so we decided to take a look,” Curlin said. It turns out to be one of the most important things we’ve found, and it’s probably not limited to covid vaccines. We may be seeing important immune function.
Among the people who agreed to switch arms in the study, researchers matched 54 pairs for age, sex, and the time difference between vaccination and exposure—half received the two doses in one arm and half in both.
Two weeks after the second dose, researchers did not see much difference in the immune response. After three weeks, however, researchers measured large amounts of antibodies capable of binding to and destroying the SARS-CoV-2 virus in blood samples. It increased from 1.3-fold to 4-fold compared to the micron variation of the virus.
“Any further improvement could save more lives,” Curlin said.
More research is needed
At this point, most people have long ago been exposed to the SARS-CoV-2 virus through vaccination, infection, or both.
Although the new study focused on the vaccine against Covid-19, the researchers said they expect the enhanced immune response to be similar to other multi-dose vaccines. They call for more research to determine if the anti-vaccination improves the immune response to other vaccines, especially in children.
“Multiple prime-boost vaccination regimens are important components of pediatric treatment, and immune responses may vary among children,” they wrote.
Curlin said more research is needed and it is too soon to make clinical recommendations based on the results of this study. If and when a new virus emerges that requires a new two-dose vaccine, Curlin said he won’t hesitate.
“I’m going to shift my hand up,” he said.
Reference: “Two-dose mRNA vaccine enhances antibody response” by Sedigeh Fazli, Arcana Thomas, Abram E. Estrada, Hiro AP Ross, David Extona Lee, Steven Kazmirczak, Mark K. Slilka, David Montefiori, William B. Messer, and Marcel E. Curlin, 16 Jan. 2024; Journal of Clinical Investigation.
DOI: 10.1172/JCI176411
The study was supported by the MJ Murdock Charitable Trust; OHSU Foundation; and the National Institutes of Health Award R01AI145835 and P51OD011092.