Table 1.
SAR in contacts of delta-exposed index cases recruited to the ATACCC2 study
| Total | PCR positive | PCR negative | SAR (95% CI) | p value | |
|---|---|---|---|---|---|
| Contacts | |||||
| All | 231 | 53 | 178 | 23 (18–29) | NA |
| Fully vaccinated | 140 | 31 | 109 | 22 (16–30) | 0·16 |
| Unvaccinated | 44 | 15 | 29 | 34 (22–49) | .. |
| Partially vaccinated | 47 | 7 | 40 | 15 (7–28) | NA |
| Household contacts | |||||
| All | 205 | 53 | 152 | 26 (20–32) | NA |
| Fully vaccinated | 126 | 31 | 95 | 25 (18–33) | 0·17 |
| Unvaccinated | 40 | 15 | 25 | 38 (24–53) | .. |
| Partially vaccinated | 39 | 7 | 32 | 18 (9–33) | NA |
χ2 test was performed to calculate p values for differences in SAR between fully vaccinated and unvaccinated cases. One PCR-negative contact who withdrew from the study without vaccination status information was excluded. NA=not applicable. SAR=secondary attack rate.