New Study Reveals Significant Increase in Immune Response with Alternating Arms for Multi-Dose Vaccinations, Including COVID-19 Vaccine
In a groundbreaking new study, researchers have discovered that alternating arms for multi-dose vaccinations, including the COVID-19 vaccine, can significantly increase immune response. This finding challenges previous assumptions that arm choice does not affect the effectiveness of immunization and has important implications for enhancing vaccine efficacy against variants like omicron. The study, which involved 947 participants and was published in The Journal of Clinical Investigation, could shape clinical practices globally and lead to improved vaccination strategies.
The research was led by scientists at Oregon Health & Science University (OHSU) and involved measuring the antibody response in the blood of individuals who received two-dose vaccinations against COVID-19 early in the pandemic. Participants included OHSU employees who agreed to enroll in the study while getting vaccinated against the SARS-CoV-2 virus. They were randomized to receive the second dose in either the same arm or the opposite arm as the first dose.
Historically, clinicians believed that arm choice didn’t matter when it came to vaccinations. However, the new study found that alternating arms resulted in a substantial increase in the magnitude and breadth of the antibody response compared to those who did not alternate arms. This improved response was observed three weeks after the second booster and persisted beyond 13 months after boosting. Notably, participants who alternated arms showed heightened immunity to both the original SARS-CoV-2 strain and the omicron variant.
While researchers aren’t exactly sure why alternating arms leads to a stronger immune response, they speculate that giving a shot in each arm activates new immune responses in different lymph nodes. “By switching arms, you basically have memory formation in two locations instead of one,” explained senior author Marcel Curlin, M.D., associate professor of medicine at OHSU.
The study’s findings are particularly significant considering the ongoing threat of COVID-19 variants like omicron. The increased immune response observed in participants who alternated arms could potentially enhance vaccine efficacy against these variants. “Any incremental improvement might save a lot of lives,” said Curlin.
The research conducted at OHSU was part of a series of laboratory studies using blood drawn from willing employees early in the COVID-19 pandemic. This line of research has produced several published studies related to the durability, breadth, and potency of immune response following vaccination and breakthrough infections. The question of whether alternating arms made a difference in the two-dose regimen had not been extensively studied before this research.
While the study focused on COVID-19 vaccination, researchers believe that the improved immune response observed with alternating arms could be similar for other multi-dose vaccinations. They call for further research to determine whether this vaccination strategy improves immune response for other vaccines, especially among children. Pediatric care often involves prime-boost vaccine regimens, and understanding how arm choice affects immune responses in children is crucial.
It is important to note that further study is needed before making clinical recommendations based on the results of this study. However, the findings provide valuable insights into optimizing vaccination strategies and highlight the potential benefits of alternating arms for multi-dose vaccinations. In the future, if a new virus emerges requiring a new two-dose vaccine, alternating arms could be a simple yet effective way to enhance immune response.
The study was supported by the M.J. Murdock Charitable Trust, the OHSU Foundation, and the National Institutes of Health. The researchers emphasize the need for continued research in this area to improve our understanding of immune responses to vaccinations and to develop evidence-based clinical recommendations.
In conclusion, the new study revealing a significant increase in immune response with alternating arms for multi-dose vaccinations has the potential to revolutionize vaccination strategies. By challenging previous assumptions and highlighting the importance of arm choice, this research opens up new possibilities for enhancing vaccine efficacy against variants like omicron. While further study is needed, the findings provide valuable insights into optimizing immune responses and could have far-reaching implications for public health worldwide.
