OBJECTIVES: The negative impact of climate change on human health and the pharmaceutical industry’s impact on the environment are well-documented. However, not all healthcare is created equal from an environmental perspective. Negative impacts of R&D, manufacturing, distribution, use, and disposal can potentially be offset by preventing future illness and resource-intensive healthcare. Prophylaxis is cost-effective, but is it environmentally favorable? This literature review explores the holistic environmental impact of vaccination.

METHODS: A targeted literature search of PubMed, ISPOR archives, and Google covering academic and gray literature sources from 2019-2023 was conducted. The search utilized two primary search strings with vaccination and environmental impact terms.

RESULTS: 1,692 sources were accessed, reduced to 36 abstracts based on keyword refinement and title review; data were extracted from 26. 20 were peer-reviewed, of which 14 examined the negative environmental impact from the production, use, and disposal of vaccines, predominantly emissions. No sources converted environmental into economic impact. 4 publications, all industry-sponsored whitepapers, examined potential reductions in healthcare resource utilization based on vaccination averting negative environmental impact. One by GSK demonstrated 18% carbon savings from hospitalizations avoided due to herpes zoster vaccination. Another by AZ showed that per-case influenza treatment costs ~15x the carbon of each vaccination. No consistent methodology was used for the quantification of either negative environmental impacts or their potential offsets.

CONCLUSIONS: Our research finds that peer-reviewed publications have focused on the negative upstream effects of vaccines, and that gaps to understand the holistic net impact are being filled by manufacturers. The hypothesis that vaccination may be net positive environmentally cannot be confirmed/refuted based on current evidence. Continued research is needed to develop standardized methodologies and prevent greenwashing in this nascent field. Converting impact to net cost and the effect of alternative options (e.g., orals and microneedle patches) should also be explored.