[Correspondence] Population size and vaccination rates for zero-dose estimates – Authors' reply

Neema Kumari and colleagues express concerns about the estimates of zero-dose children in India and, more generally, the use of absolute numbers versus relative metrics in our Article1 for understanding the state of health systems globally. We agree that relative metrics are crucial for understanding successes and gaps in equitable health care, and much of our Article centred on vaccine coverage, rather than numbers of unvaccinated children. In addition to emphasising the importance of addressing relative disparities, however, the Immunization Agenda 2030 (IA2030) also sets a global goal to reduce the number of zero-dose children by 50% by 2030.