A useful link for discussion around external benefits of consumption, positive and negative externalities:

https://timesofindia.indiatimes.com/india/vaccine-refusal-among-top-10-threats-to-public-health-who/articleshow/67664734.cms

Edexcel spec reference 1.3.2 d) the external benefits of consumption using marginal analysis

AQA spec reference 4.1.8.4  Positive and negative externalities in consumption and production

OCR spec reference P14 Explain, with the aid of a diagram, what is meant by positive and negative externalities (external benefits and external costs) of consumption