Table 2.

Provaccine and antivaccine topics from thematic analysis on social media articles.

Category and subcategory			Explanation
Provaccine
	Safety and efficacy	Content on confidence in the safety or efficacy of vaccines.
	Positive attitude	Content reflecting positive attitudes toward vaccines and government measures. It includes viewing vaccination as an act of dismantling systemic racism, being positive about the development of vaccines and antivirals, and expressing concerns on the antivaccine movement.
	Criticizing antivaccine beliefs	Content that expresses support for vaccines by blaming antivaxxers. It includes accusing, ridiculing, and insulting antivaxxers for spreading falsehoods and misinformation.
	Promotion	Content that advocates infection control measures and touts the prior success of immunizations.
Antivaccine
	Safety or effectiveness concerns	Content that lacks confidence in the safety or efficacy of vaccines, such as fear of health hazards, side effects, allergic reactions, or death attributable to vaccines; skepticism about vaccine trials; and inability of vaccines to prevent COVID-19.
	Vaccine alternatives	Content that believes there are better immunization options than vaccines. It includes belief in God’s protection; protective behaviors, such as sunbathing, healthy eating, and exercise; and natural immunity from COVID-19 infection.
	Morality and ethics	Content of vaccines offending liberty. It includes mandatory government policies, and loss of personal choice and freedom.
	Misinformation	Content that disseminates false information about side effects, and vaccine production and transport. It includes scientific misinformation directly contrary to vaccine research and political misinformation of untrue government interventions.
	Conspiracy	Content on scientific, political, or racial conspiracy theories. It includes deliberately created viruses, nonexistence of vaccines, microchips in vaccines, conflicts of interest between the government and pharmaceutical companies, genocide conspiracies, and right-wing politics.
	Vaccine hesitancy	Content refers to delay in acceptance or refusal of vaccination despite availability of vaccination services.