New Delhi: Getting the second Covid jab on the same arm as the first one or on the opposite arm could influence the body’s immune response generated against the SARS-CoV-2 virus, new research from Germany says. Those who got jabbed on the same side, or ipsilaterally, generated more antibodies against the Covid-causing pathogen than those who got jabbed on the opposite side, or contralaterally, the study from Saarland University and other German institutes found.
Further, median levels of infection-fighting CD8 T-cells generated in response to the spike-protein of the pathogen were found to be significantly lower in those contralaterally vaccinated. CD8 T-cells destroy virus-infected cells and render protection against severe disease.
Consequently, after contralateral vaccination, fewer individuals (43 per cent) were found to have detectable levels of CD8 T-cells than after ipsilateral vaccination (67 per cent), the study published in the journal eBioMedicine said.
Individual doses of two-dose vaccine-regimens are consecutively administered into the deltoid muscle, which is the large triangular muscle covering the shoulder joint. The authors wrote in the study,
However, little attention has so far been paid to the immunological effects of choosing the ipsilateral or the contralateral side for the second dose.
The study was performed in 303 never-infected individuals (aged 24-55), of whom 147 received the second Pfizer BioNTech COVID-19 vaccine dose on the ipsilateral side and 156 on the contralateral side. Blood samples were drawn 15 days after the second dose and measured for antibodies and immune T-cells produced in response to the SARS-CoV-2 spike.
While both ipsilateral and contralateral vaccination induce a strong immune response, secondary boosting was more pronounced when choosing the same routes used for administering the vaccine the first time, the researchers wrote in the study.
This may be because after ipsilateral vaccination, boosting of the immune response after the first and the second dose both occurred through the same lymph nodes, which is where the infection-fighting fluid containing CD8 T-cells is produced, they wrote.
This was supported by previous research which, they said, demonstrated that ipsilateral lymph nodes where the vaccine had been applied were significantly larger in size and showed higher metabolic activity compared to the contralateral lymph nodes. Considering these findings, the authors wrote in the study,
The choice of arm for the second vaccination represents a previously unappreciated factor that may contribute to overall vaccine effectiveness on a population level.
(This story has not been edited by NDTV staff and is published from a syndicated feed.)
NDTV – Dettol have been working towards a clean and healthy India since 2014 via the Banega Swachh India initiative, which is helmed by Campaign Ambassador Amitabh Bachchan. The campaign aims to highlight the inter-dependency of humans and the environment, and of humans on one another with the focus on One Health, One Planet, One Future – Leaving No One Behind. It stresses on the need to take care of, and consider, everyone’s health in India – especially vulnerable communities – theLGBTQ population,indigenous people, India’s different tribes, ethnic and linguistic minorities, people with disabilities, migrants, geographically remote populations, gender and sexual minorities. In wake of the currentCOVID-19 pandemic, the need for WASH (Water,SanitationandHygiene) is reaffirmed as handwashing is one of the ways to prevent Coronavirus infection and other diseases. The campaign will continue to raise awareness on the same along with focussing on the importance of nutrition and healthcare for women and children, fightmalnutrition, mental wellbeing, self care, science and health,adolescent health & gender awareness. Along with the health of people, the campaign has realised the need to also take care of the health of the eco-system. Our environment is fragile due to human activity, which is not only over-exploiting available resources, but also generating immense pollution as a result of using and extracting those resources. The imbalance has also led to immense biodiversity loss that has caused one of the biggest threats to human survival – climate change. It has now been described as a “code red for humanity.” The campaign will continue to cover issues likeair pollution,waste management,plastic ban,manual scavengingand sanitation workers andmenstrual hygiene. Banega Swasth India will also be taking forward the dream of Swasth Bharat, the campaign feels that only a Swachh or clean India wheretoiletsare used andopen defecation free (ODF)status achieved as part of the Swachh Bharat Abhiyan launched byPrime Minister Narendra Modiin 2014, can eradicate diseases like diahorrea and the country can become a Swasth or healthy India.