Flu Vaccines

Efficacy

Cochrane reviews are recognized globally as the highest standard in evidence-based healthcare due to their transparency, reproducibility, and independence from commercial interests. A major Cochrane review found no convincing evidence that flu shots reduce mortality, hospitalizations, severe complications, or community spread of influenza. PMID:29388195, PMID:29388196, PMID:293188197

Other research raises additional concerns. A placebo-controlled study from the University of Hong Kong compared vaccinated children with unvaccinated children and found no difference in flu rates, but vaccinated children had a 4-times higher rate of non-influenza respiratory infections. PMID:22423139

Researchers at Columbia University found a similar pattern: flu risk was the same in the first 14 days after vaccination, but the risk of other respiratory pathogens was significantly higher in vaccinated individuals. PMID:29525279

The Cleveland Clinic followed 53,402 employees across several states. Early in the study, flu rates were similar in both groups. But over time, the cumulative incidence of influenza increased faster in the vaccinated than in the unvaccinated. medRxiv link

Why they're widely promoted

Providers

There are both direct and indirect financial incentives for providers (e.g., physicians, clinics, hospitals), though they are often practice- or institution-level rather than personal kickbacks, which are illegal under anti-kickback laws. These encourage uptake without directly tying pay to individual shots.

Vaccination rates, particularly for influenza, are integrated into key quality measurement systems like HEDIS and MIPS in the U.S. healthcare system. These systems evaluate provider and plan performance, directly influencing financial reimbursements through bonuses, adjustments, or penalties. This creates a strong incentive for clinics, hospitals, and practices to prioritize flu shots, as higher rates can translate to tangible revenue gains—often in the range of 1–5% of Medicare/Medicaid payments, depending on performance thresholds and payer contracts.

Pharmacies and warehouse clubs

Pharmacies (e.g., CVS, Walgreens) and warehouse clubs (e.g., Walmart, Costco) aggressively promote flu shots as a low-barrier service, often at no out-of-pocket cost to patients (covered by insurance). This is highly profitable—not from high margins per shot, but through scale and synergies. In 2022–2023, U.S. pharmacies administered ~50% of flu vaccines, generating $4–5B in related revenue.

• Direct Profitability: Gross margins are slim (~$15 per shot after vaccine costs of $10–20, reimbursed by insurers), but volume is massive—CVS alone did 25M+ shots in peak seasons, yielding $300–500M annually. Walmart and Costco bundle into membership perks, with fees adding $5–10 profit.

• Indirect Incentives and Upsell Opportunities: Shots drive foot traffic (e.g., 20–30% sales lift during flu season), encouraging impulse buys like vitamins, tissues, or prescriptions. Retailers offer coupons ($5–20 off next purchase) or free groceries to lure customers, turning a $40 service into $100+ in ancillary sales.

• Staff and Operational Perks: Managers push quotas for bonuses/raffles (e.g., CVS beach days for high-volume stores), and it's a low-overhead service (10-min admin by pharmacists).

• Broader Business Strategy: Enhances brand loyalty and positions stores as "health hubs," especially post-COVID. A 2020 surge saw 10–15% new customers via flu/COVID combos, boosting long-term revenue.