Detection of Severe Acute Respiratory Syndrome Coronavirus 2 in Pregnant Women Treated with Nirmatrelvir/Ritonavir (Paxlovid) Using Salivary Polymerase Chain Reaction: A Prospective Cohort Study.

OBJECTIVES

We aim to study the relative viral load using salivary polymerase chain reaction among pregnant women treated with Paxlovid.

METHODS

Pregnant women with coronavirus disease 2019 were allocated to two groups: those receiving Paxlovid and those receiving no antiviral agents. We compared the nasopharyngeal and salivary relative viral loads and their changes in saliva specimens.

RESULTS

Among the thirty-seven pregnant women, seventeen received Paxlovid, and twenty received no antiviral agents. The viral cycle threshold value of saliva was significantly higher than that from nasopharynx, with a median ± interquartile range of 26.44 ± 7.68 versus 17.6 ± 9.6 in the Paxlovid group ( = 0.005). Following treatment, the median salivary viral load decreased by 13.40 cycle threshold values in the Paxlovid group (from a median of [Day 0 Ct] to [Day 4/5 Ct]), compared to a change of -1.59 cycle threshold values in the no-antiviral group (from a median of [Day 0 Ct] to [Day 4/5 Ct]) ( = 0.021). The detection rate of coronavirus disease 2019 using salivary polymerase chain reaction was 83.8% (31/37).

CONCLUSIONS

This study showed that saliva is a useful diagnostic tool for coronavirus disease 2019 in pregnant women, and a significant decrease in the relative viral load of saliva was observed in those treated with Paxlovid.