Antiviral Nasal Sprays — Meta-Analysis
The top “across all compounds” plots compare every nasal spray on one outcome, standardized to Cohen's d (positive = favors treatment) so different scales and units pool together; each compound is a subgroup with its own subtotal. Below, one forest plot per ingredient × outcome × effect measure (≥2 trials), with a standardized plot leading each ingredient×outcome group. Pooled diamonds are random-effects (DerSimonian–Laird). (16 pooled.)
Across all compounds
Exploratory class-level pools — antivirals differ, so heterogeneity is high; read the prediction interval, per-compound subtotals, and the not-poolable appendix, not just the diamond.
Symptom duration — all compounds
Standardized (SMD)20 trials · 15 compounds · I² = 89.7%Every compound pooled on one Cohen's-d scale (positive = favors treatment), combining continuous, hazard ratio, mean difference, odds ratio via Hedges' g, Chinn's OR→SMD, mean-difference→SMD (pooled-SD back-calculation) and an lnHR≈lnOR approximation. Pooling across different antivirals is exploratory — heterogeneity is high, so read the prediction interval, not just the diamond.
Heterogeneity: I² = 89.7%, τ² = 0.052 · 95% prediction interval -0.17 to 0.83
28 more studies reported this outcome but couldn't be standardized (shown, not pooled)
- Douglas 1974 — Cp-20,961 (avridine) · Mean difference · no standardizable statistics (missing SD/CI/arm-N)
- Waldman 1978 — Cp-20,961 (avridine) · Mean difference · no standardizable statistics (missing SD/CI/arm-N)
- Farr 1984 — Interferon alpha (unspecified subtype) · Risk difference · no standardizable statistics (missing SD/CI/arm-N)
- Hayden 1984 — Interferon alpha (unspecified subtype) · Mean difference · no standardizable statistics (missing SD/CI/arm-N)
- Frederick 1985 — Interferon alpha (unspecified subtype) · no standardizable statistics (missing SD/CI/arm-N)
- Christian 1986 — Interferon alpha (unspecified subtype) · Mean difference · no standardizable statistics (missing SD/CI/arm-N)
- Monto 1986 — Interferon alpha-2b · Mean difference · no standardizable statistics (missing SD/CI/arm-N)
- Hayden 1988 — Interferon alpha-2b · Mean difference · no standardizable statistics (missing SD/CI/arm-N)
- Tannock 1988 — Interferon alpha-2a · no standardizable statistics (missing SD/CI/arm-N)
- Sperber 1989 — Interferon beta serine · Mean difference · no standardizable statistics (missing SD/CI/arm-N)
- Robert 1990 — Interferon (unspecified) · no standardizable statistics (missing SD/CI/arm-N)
- Wiselka 1991 — Interferon alpha (unspecified subtype) · Mean difference · no standardizable statistics (missing SD/CI/arm-N)
- Sperber 1992 — Interferon beta serine · Mean difference · no standardizable statistics (missing SD/CI/arm-N)
- Hayden 1996 — Zanamivir (gg167) · Mean difference · no standardizable statistics (missing SD/CI/arm-N)
- Adam 1998 — Hypertonic saline · Hazard ratio · no standardizable statistics (missing SD/CI/arm-N)
- Edward 2001 — Zinc sulfate · Hazard ratio · no standardizable statistics (missing SD/CI/arm-N)
- Susan 2002 — Zanamivir · Mean difference · no standardizable statistics (missing SD/CI/arm-N)
- Eby 2006 — Zinc gluconate · Risk ratio · no standardizable statistics (missing SD/CI/arm-N)
- Hull 2007 — Hydroxypropyl methylcellulose (hpmc) · Mean difference · no standardizable statistics (missing SD/CI/arm-N)
- James 2007 — Citrate/phosphate buffer · Mean difference · no standardizable statistics (missing SD/CI/arm-N)
- Tamas 2012 — Iota-carrageenan · Mean difference · no standardizable statistics (missing SD/CI/arm-N)
- Martin 2014 — Iota-carrageenan · Mean difference · no standardizable statistics (missing SD/CI/arm-N)
- Eccles 2015 — Iota-carrageenan · no standardizable statistics (missing SD/CI/arm-N)
- Ю.В. 2016 — Nazoferon · no standardizable statistics (missing SD/CI/arm-N)
- Безрукова 2021 — Interferon alpha-2b · Mean difference · no standardizable statistics (missing SD/CI/arm-N)
- Marcos 2022 — Chlorpheniramine maleate · no standardizable statistics (missing SD/CI/arm-N)
- al. 2023 — A8g6 antibody cocktail · Mean difference · no standardizable statistics (missing SD/CI/arm-N)
- Cristiana 2026 — Resveratrol/carboxymethyl-beta-glucan (linfovir) · Mean difference · no standardizable statistics (missing SD/CI/arm-N)
Viral load — all compounds
Standardized (SMD)20 trials · 16 compounds · I² = 84.3%Every compound pooled on one Cohen's-d scale (positive = favors treatment), combining continuous, hazard ratio, mean difference, odds ratio via Hedges' g, Chinn's OR→SMD, mean-difference→SMD (pooled-SD back-calculation) and an lnHR≈lnOR approximation. Pooling across different antivirals is exploratory — heterogeneity is high, so read the prediction interval, not just the diamond.
Heterogeneity: I² = 84.3%, τ² = 0.2075 · 95% prediction interval -0.68 to 1.33
56 more studies reported this outcome but couldn't be standardized (shown, not pooled)
- Gatmaitan 1973 — Cp-20,961 (avridine) · no standardizable statistics (missing SD/CI/arm-N)
- Douglas 1974 — Cp-20,961 (avridine) · Mean difference · no standardizable statistics (missing SD/CI/arm-N)
- Reed 1976 — Skf 40491, glr9-338, rp l9326, ici 73,602 · Mean difference · no standardizable statistics (missing SD/CI/arm-N)
- Stanley 1976 — Cp-20,961 (avridine) · Risk difference · no standardizable statistics (missing SD/CI/arm-N)
- Yasushi 1977 — 1-phenyl-3-(4-phenyl-2-thiazolyl) guanidine (cl 88,277) · Rate ratio · no standardizable statistics (missing SD/CI/arm-N)
- Aoki 1978 — Brl 5907 (polynucleotide interferon inducer of fungal origin) · no standardizable statistics (missing SD/CI/arm-N)
- Stephen 1978 — Leukocyte/lymphoblastoid interferon · Mean difference · no standardizable statistics (missing SD/CI/arm-N)
- Waldman 1978 — Cp-20,961 (avridine) · Risk ratio · no standardizable statistics (missing SD/CI/arm-N)
- Hayden 1982 — Enviroxime · Risk difference · no standardizable statistics (missing SD/CI/arm-N)
- Levandowski 1982 — Enviroxime · no standardizable statistics (missing SD/CI/arm-N)
- Hayden 1983 — Interferon alpha (unspecified subtype) · Risk ratio · no standardizable statistics (missing SD/CI/arm-N)
- Higgins 1983 — Interferon alpha (unspecified subtype) · Risk ratio · no standardizable statistics (missing SD/CI/arm-N)
- Phillpotts 1983 — Interferon alpha (unspecified subtype) · Risk ratio · no standardizable statistics (missing SD/CI/arm-N)
- Phillpotts 1983 — Enviroxime · Risk ratio · no standardizable statistics (missing SD/CI/arm-N)
- Samo 1983 — Leukocyte/lymphoblastoid interferon · Risk ratio · no standardizable statistics (missing SD/CI/arm-N)
- Hayden 1984 — Interferon alpha (unspecified subtype) · Risk difference · no standardizable statistics (missing SD/CI/arm-N)
- Samo 1984 — Interferon alpha (unspecified subtype) · Risk ratio · no standardizable statistics (missing SD/CI/arm-N)
- Douglas 1985 — Interferon alpha (unspecified subtype) · Risk ratio · no standardizable statistics (missing SD/CI/arm-N)
- Higgins 1986 — Interferon beta serine · Mean difference · no standardizable statistics (missing SD/CI/arm-N)
- Turner 1986 — Interferon alpha-2b · no standardizable statistics (missing SD/CI/arm-N)
- Al-Nakib 1987 — 4',6-dichloroflavan · no standardizable statistics (missing SD/CI/arm-N)
- HJORDIS 1987 — Interferon alpha (unspecified subtype) · Mean difference · no standardizable statistics (missing SD/CI/arm-N)
- Frederick 1988 — Rhinovirus receptor murine monoclonal antibody (rrma) · no standardizable statistics (missing SD/CI/arm-N)
- Hayden 1988 — Interferon alpha-2b · Risk ratio · no standardizable statistics (missing SD/CI/arm-N)
- Sperber 1988 — Interferon beta serine · no standardizable statistics (missing SD/CI/arm-N)
- Dearden 1989 — R61837 · no standardizable statistics (missing SD/CI/arm-N)
- Sperber 1992 — Interferon beta serine · Risk ratio · no standardizable statistics (missing SD/CI/arm-N)
- Frederick 1995 — Pirodavir · Risk difference · no standardizable statistics (missing SD/CI/arm-N)
- Hayden 1996 — 4-guanidino-neu5ac2en (gg167) · Mean difference · no standardizable statistics (missing SD/CI/arm-N)
- Frederick 1997 — Zanamivir · Mean difference · no standardizable statistics (missing SD/CI/arm-N)
- Jack 2002 — Interferon alpha-2b · Mean difference · no standardizable statistics (missing SD/CI/arm-N)
- Susan 2002 — Zanamivir · Mean difference · no standardizable statistics (missing SD/CI/arm-N)
- James 2007 — Citrate/phosphate buffer · Mean difference · no standardizable statistics (missing SD/CI/arm-N)
- Ron 2010 — Iota-carrageenan · Mean difference · no standardizable statistics (missing SD/CI/arm-N)
- Tamas 2012 — Iota-carrageenan · Mean difference · no standardizable statistics (missing SD/CI/arm-N)
- Martin 2013 — Iota-carrageenan · Mean difference · no standardizable statistics (missing SD/CI/arm-N)
- Martin 2014 — Iota-carrageenan · Mean difference · no standardizable statistics (missing SD/CI/arm-N)
- Zhang 2014 — Ribavirin · Risk ratio · no standardizable statistics (missing SD/CI/arm-N)
- Ю.В. 2016 — Nazoferon · no standardizable statistics (missing SD/CI/arm-N)
- Kalyuzhin 2018 — Interferon alpha-2b · no standardizable statistics (missing SD/CI/arm-N)
- Charles 2021 — Baby shampoo · Mean difference · no standardizable statistics (missing SD/CI/arm-N)
- Yilmaz 2021 — Hypertonic alkaline nasal irrigation · Mean difference · no standardizable statistics (missing SD/CI/arm-N)
- Hazem 2022 — Povidone-iodine plus glycyrrhizic acid · Risk ratio · no standardizable statistics (missing SD/CI/arm-N)
- Julie 2022 — Povidone-iodine · no standardizable statistics (missing SD/CI/arm-N)
- Marcos 2022 — Chlorpheniramine maleate · no standardizable statistics (missing SD/CI/arm-N)
- Reza 2022 — Saliravira (herbal compound) · Mean difference · no standardizable statistics (missing SD/CI/arm-N)
- Rujipas 2022 — Povidone-iodine · Mean difference · no standardizable statistics (missing SD/CI/arm-N)
- Shankar 2022 — Povidone-iodine · no standardizable statistics (missing SD/CI/arm-N)
- Batioglu-Karaaltin 2023 — Povidone-iodine / hypertonic alkaline / saline nasal lavage · Mean difference · no standardizable statistics (missing SD/CI/arm-N)
- Caroline 2023 — Iota-carrageenan · no standardizable statistics (missing SD/CI/arm-N)
- Rui 2023 — Igm-like ace2 fusion protein (hh-120) · Hazard ratio · no standardizable statistics (missing SD/CI/arm-N)
- Song 2023 — Igm-like ace2 fusion protein (hh-120) · no standardizable statistics (missing SD/CI/arm-N)
- Zhang 2023 — A8g6 antibody cocktail · no standardizable statistics (missing SD/CI/arm-N)
- Francesca 2024 — Inna-051 · Mean difference · no standardizable statistics (missing SD/CI/arm-N)
- Peter 2024 — Povidone-iodine · Mean difference · no standardizable statistics (missing SD/CI/arm-N)
- Thomas 2025 — Povidone-iodine · Mean difference · no standardizable statistics (missing SD/CI/arm-N)
By compound
iota-carrageenan
Quality of lifeStandardized (SMD)Std. mean difference · 2 trials · I² = 43.4%Standardized effect size (Cohen's d): combines continuous & odds ratio onto one scale via Hedges' g and Chinn's OR→SMD conversion (an approximation). Positive = favors treatment. 2 trials converted from binary.
iota-carrageenan
Symptom durationStandardized (SMD)Std. mean difference · 2 trials · I² = 89.2%Standardized effect size (Cohen's d): combines hazard ratio & mean difference onto one scale via Hedges' g and Chinn's OR→SMD conversion (an approximation). Positive = favors treatment. 2 trials converted from binary.
iota-carrageenan
Symptom severityStandardized (SMD)Std. mean difference · 3 trials · I² = 50.2%Standardized effect size (Cohen's d): combines continuous & mean difference onto one scale via Hedges' g and Chinn's OR→SMD conversion (an approximation). Positive = favors treatment. 3 trials converted from binary.
iota-carrageenan
Symptom severityMean difference · 2 trials · I² = 64.3%zanamivir
Influenza symptom durationStandardized (SMD)Std. mean difference · 3 trials · I² = 67.7%Standardized effect size (Cohen's d): combines continuous & mean difference onto one scale via Hedges' g and Chinn's OR→SMD conversion (an approximation). Positive = favors treatment. 3 trials converted from binary.
zanamivir
Influenza symptom durationMean difference · 3 trials · I² = 0%povidone-iodine
Symptom severityStandardized (SMD)Std. mean difference · 2 trials · I² = 0%Standardized effect size (Cohen's d): combines continuous & mean difference onto one scale via Hedges' g and Chinn's OR→SMD conversion (an approximation). Positive = favors treatment. 2 trials converted from binary.
povidone-iodine
Viral loadStandardized (SMD)Std. mean difference · 3 trials · I² = 46.9%Standardized effect size (Cohen's d): combines continuous & odds ratio onto one scale via Hedges' g and Chinn's OR→SMD conversion (an approximation). Positive = favors treatment. 3 trials converted from binary.
azelastine
Symptom durationStandardized (SMD)Std. mean difference · 2 trials · I² = 80.4%Standardized effect size (Cohen's d): combines continuous & hazard ratio onto one scale via Hedges' g and Chinn's OR→SMD conversion (an approximation). Positive = favors treatment. 2 trials converted from binary.
azelastine
Viral loadStandardized (SMD)Std. mean difference · 2 trials · I² = 0%Standardized effect size (Cohen's d): combines continuous onto one scale via Hedges' g and Chinn's OR→SMD conversion (an approximation). Positive = favors treatment. 2 trials converted from binary.
nitric oxide (nons)
Viral loadStandardized (SMD)Std. mean difference · 2 trials · I² = 64.2%Standardized effect size (Cohen's d): combines continuous & mean difference onto one scale via Hedges' g and Chinn's OR→SMD conversion (an approximation). Positive = favors treatment. 2 trials converted from binary.
nitric oxide (nons)
Viral loadMean difference · 2 trials · I² = 51%interferon alpha-2b
Symptom durationStandardized (SMD)Std. mean difference · 2 trials · I² = 52.4%Standardized effect size (Cohen's d): combines continuous onto one scale via Hedges' g and Chinn's OR→SMD conversion (an approximation). Positive = favors treatment. 2 trials converted from binary.
interferon beta serine
Symptom severityStandardized (SMD)Std. mean difference · 2 trials · I² = 42.9%Standardized effect size (Cohen's d): combines continuous onto one scale via Hedges' g and Chinn's OR→SMD conversion (an approximation). Positive = favors treatment. 2 trials converted from binary.