Saline rinses may help prevent COVID-19 hospitalization

A study presented at ACAAI 2023 demonstrated the potential of simple home remedies such as gargling and nasal rinsing with saltwater in cutting COVID-19 hospitalization rates.

“High viral loads and successful isolation from early throat swabs suggest potential SARS-CoV-2 replication in upper respiratory tract tissues … Prior studies demonstrated that hypertonic saline nasal irrigation and gargling reduced symptom duration of coronavirus upper respiratory infections,” said study lead author Sebastian Espinoza, a student at Trinity University, San Antonio, Texas, US, during his presentation at ACAAI 2023.

“[We thus hypothesized] that interventions targeting the upper respiratory tract are likely to reduce the viral load with the potential to reduce the frequency and duration of upper respiratory symptoms associated with COVID-19 disease,” he noted.

Espinoza and his team sought to determine the role of two regimens using low and high concentrations of saline solution, as well as the frequency and duration of symptoms associated with COVID-19.

The team also compared the frequency of hospital or intensive care unit (ICU) admissions, mechanical ventilator use, or death between individuals using gargling and nasal rinsing with low- and high-saline solutions.

The study included 58 individuals (mean age 40 years, 60 percent female) with documented COVID-19 infection via PCR. They were randomized 1:1 to either low- or high-saline gargling and nasal rinsing. The low- and high-saline solutions consisted of 2.13 g and 6.00 g of salt, respectively, dissolved in 8 oz of warm water. Participants were instructed to perform gargling and nasal rinsing for 5 minutes four times daily for 14 days after enrolment.

More than 9,000 individuals who tested positive for COVID-19 comprised the reference population. Individuals concurrently using azithromycin, chloroquine, hydroxychloroquine, or remdesivir were eligible to participate in the study. [ACAAI 2023, abstract P244]

There were no differences between the low- and high-saline regimen arms in terms of frequency (n=7 vs 5; p=0.97) or duration (n=7 vs 6 days; p=0.75) of symptoms, as well as the proportion of individuals who completed 14 days of treatment (74 percent vs 75 percent; p=0.94).

Similarly, there were no significant differences in hospital admission (18.5 percent vs 21.4 percent; p=0.79), ICU admission (7.4 percent vs 3.6 percent; p=0.61), or mechanical ventilator use (0.0 percent vs 1.0 percent; p=0.32) between the low- or high-saline regimen arms.

However, hospitalization rates in the saline regimen arms were markedly lower than that observed in the reference cohort, which was roughly 60 percent. Comparisons of the low- and high-saline regimens with the reference cohort both yielded p-values of <0.001.

“Given our findings, we conclude that low- and high-saline regimens for gargling and nasal rinsing are tied to similar clinical outcomes related to COVID-19,” said Espinoza. “Of note, both saline regimens appear to be associated with lower hospitalization rates compared with no gargling or nasal rinsing in individuals infected with COVID-19.” However, the study was not designed to evaluate this comparison.

Therefore, additional randomized trials designed to determine the role of saline gargling and nasal rinsing in COVID-19 infection are required to ascertain the findings. “If confirmed, this simple intervention could be beneficial for individuals with COVID-19, particularly in low-resource settings,” Espinoza concluded.