Bacterial lysates OM-85

Other immunostimulants

ATC code: L03AX-OM85 (Bacterial lysate OM-85 systemic (local code))

Mechanism of action

Lyophilised lysates of 8 bacterial species: Haemophilus influenzae, Streptococcus pneumoniae, Klebsiella pneumoniae, Klebsiella ozaenae, Staphylococcus aureus, Streptococcus pyogenes, Streptococcus viridans, Moraxella catarrhalis. The manufacturer claims dendritic cell and T-lymphocyte activation, enhanced secretory IgA synthesis, and modulation of cellular immune response. Unlike many Russian 'immunomodulators', OM-85 has a limited international evidence base: a 2012 Cochrane review found a possible reduction in URI episodes in children, but with high risk of bias.

Indications

Prevention of recurrent respiratory infections

Individual decision

A 2012 Cochrane review of bacterial lysates in children showed a possible reduction of approximately 1.2 URI episodes over 6 months. Authors noted high risk of bias in most included trials and result heterogeneity. The 2023 ERS guideline mentions OM-85 as an option for recurrent respiratory infections in children but without a strong recommendation. There are no data on long-term outcomes – severity, antibiotic use, or hospitalisations.

Adult use is a separate topic with weaker evidence. Decisions are individual with realistic expectations: the effect is limited and long-term benefits have not been demonstrated.

COVID-19

Not recommended

In 2020-2022 OM-85 was promoted for COVID-19 prevention in children with recurrent URIs. WHO, NIH, CDC, and ERS did not recommend this practice. Evidence-based prevention is vaccination, masks during high-transmission periods, and hand hygiene.

Practical notes

Russian practice note

Bronchomunal (and brands with the same OM-85 – Broncho-Vaxom, Ismigen) is widely prescribed in Russia for children with frequent URIs. Realistic benefit is a possible reduction of a few URI episodes per year without effect on severity or outcomes. Baseline measures – pneumococcal, Haemophilus, and influenza vaccination – work on evidence-robust outcomes: pneumonia, hospitalisations, mortality.

context

OM-85 stands out among 'immunomodulators' by having been studied in multicentre European RCTs and holding European registration, even if weak. This does not move it to first-line. For recurrent respiratory infections in a child, workup for hidden causes matters more: allergic rhinitis, adenoids, secondhand smoke, immunodeficiency.

Safety

Contraindications

Hypersensitivity to any component
Age under 6 months (pediatric formulation), under 12 years (adult formulation)
Acute intestinal infections

Serious adverse effects

Allergic reactions including angioedema (rare)
Post-marketing reports of thrombocytopenia (rare)

Common adverse effects

Gastrointestinal upset (nausea, abdominal pain, diarrhoea)
Headache
Rash

Pregnancy

Pregnancy data are limited. Avoid use without clear indications.

Frequently asked

What is Bacterial lysates OM-85 used for?

Bacterial lysates OM-85 is evaluated for the following indications with varying evidence strength: Prevention of recurrent respiratory infections (evidence tier D), COVID-19 (evidence tier F). See the full indication matrix with dosing and citations above on this page.

What are the side effects of Bacterial lysates OM-85?

Common side effects of Bacterial lysates OM-85 (≥ 1 in 100): Gastrointestinal upset (nausea, abdominal pain, diarrhoea), Headache, Rash. See the Safety section for uncommon and serious reactions.

Is Bacterial lysates OM-85 safe during pregnancy?

Pregnancy data are limited. Avoid use without clear indications.

Who should not take Bacterial lysates OM-85?

Bacterial lysates OM-85 is contraindicated in: Hypersensitivity to any component; Age under 6 months (pediatric formulation), under 12 years (adult formulation); Acute intestinal infections. Full list in the Safety section.