I Have Just Read That,

in the UK everyone over 65 will receive another covid booster injection this autumn/winter,

photograph Wikipedia, the article is here, so the next question, which arm to have the jab? before you say the usual one, normally not the dominate arm, have a read of this part of a text in the journal eBioMedicine, (part of The Lancet), 

'both ipsilateral and contralateral vaccination induce a strong immune response, but secondary boosting is more pronounced when choosing vaccine administration-routes that allows for drainage by the same lymph nodes used for priming. Higher neutralizing antibody activity and higher levels of spike-specific CD8 T-cells may have implications for protection from infection and severe disease and support general preference for ipsilateral vaccination... The observed differences in immunogenicity may result from the fact that priming and secondary boosting of the immune response after ipsilateral vaccination occurs in the same draining axillary lymph nodes with limited involvement of the contralateral side. Conceptually, this is supported by 18F-FDG PET/CT studies among BNT162b2-vaccine recipients demonstrating that the ipsilateral lymph nodes on the side where the vaccine had been applied were significantly larger in size and showed higher metabolic activity compared to the contralateral lymph nodes',

so the usual arm or the other one? if I read the article correctly it should not be the arm used that had your first jab, or did I read it incorrectly?