Is there an MRSA vaccine?

There is no approved MRSA vaccine. No vaccine against Staphylococcus aureus — methicillin-resistant or not — is licensed in any country. You cannot buy one, request one before surgery, or get one on a travel or occupational schedule.

That is not for want of trying. Vaccine candidates have reached Phase III trials in dialysis patients, cardiac surgery patients and spinal surgery patients. Each one failed, and one of them failed in a way that made the field considerably more cautious.

Vaccines work best against organisms we meet rarely and clear completely. Staph aureus is the opposite: around 30% of people carry it in the nose at any time, and most of us have carried it repeatedly since childhood. That creates several problems at once.

• Natural infection doesn't give immunity. People recover from a staph abscess and get another one months later. A vaccine has to beat a bar that nature has already failed.
• It attacks the immune system directly. Toxins such as Panton–Valentine leukocidin and alpha-haemolysin kill the very neutrophils that antibodies recruit — so making more antibodies alone doesn't help.
• It hides from antibodies. Protein A binds antibodies backwards, and a polysaccharide capsule and biofilm shield the surface targets a vaccine would aim at.
• Many strains, many antigens. Surface targets vary between MRSA strains, so a single-antigen vaccine can miss the lineage causing an outbreak.
• No clean animal model. Mice are not natural staph hosts, so protection in mice has repeatedly failed to translate to humans.

Research has shifted away from "raise antibodies against one surface protein" towards broader approaches:

• Multi-antigen vaccines that combine surface adhesins with neutralisation of the toxins that destroy immune cells.
• T-cell-directed vaccines using adjuvants that drive Th17 responses, based on evidence that people with defective Th17 immunity get severe recurrent staph disease.
• mRNA platforms, now being applied to bacterial antigens after their success in viral vaccines, still at preclinical and early-phase stages.
• Targeted passive immunisation — monoclonal antibodies given around high-risk surgery or ICU admission rather than lifelong vaccination.

None of these is near licensure. A realistic expectation is that any approved product will first target a narrow high-risk group — patients having implant surgery or on dialysis — rather than the general public.

Until a vaccine exists, prevention is mechanical and pharmacological rather than immunological — and it works well:

• Hand hygiene and keeping every cut, graze or surgical wound covered until fully healed.
• Not sharing towels, razors, bar soap or sports gear — the main routes in gyms and locker rooms.
• Before surgery: screening swabs, nasal mupirocin and chlorhexidine washes — the closest thing to pre-surgical protection that exists.
• For repeat infections, a full decolonisation course across the household.
• Flu vaccination, which reduces the influenza infections that precede many severe secondary staph pneumonias.