To the Editor.
—In the article by Dr Cohen and colleagues,1 Table 2 shows that the antibody titer (≤2) did not differ significantly between subjects with 6 or more ties (81/153, or 53%) and those with 1 to 5 ties (63/123, or 51%). Titer is a proxy for previous infection so that if ties confer immunity from colds, then one would expect that those with more ties would have experienced fewer colds in the past and would therefore have had significantly fewer antibodies. Alternatively, more ties could equal more past opportunities for infection, leading to more high-titer subjects, but this hypothesis is also belied by the results.The short term produced a strong ties-immunity effect, but the long term did not. Perhaps the number of ties is an ephemeral measure that does not indicate an enduring personal characteristic. For example, 5 of the items in the Social Network Index assess family relationships
Heeler RM. Social Ties and Susceptibility to the Common Cold. JAMA. 1997;278(15):1231-1232. doi:10.1001/jama.1997.03550150035019