Children are the invisible victims of the COVID-19 pandemic. Although they have a low risk of severe COVID-19 disease and death, they are suffering disproportionate harm from non-pharmaceutical public-health measures, including deleterious educational effects of school closures, and decreased social care, school feeding programs and health-service attendance1. Of grave concern are the profoundly negative effects of the pandemic on childhood immunization coverage. All six World Health Organization Regions have reported disrupted immunization activities, with major adverse effects on routine immunization, mass vaccination campaigns (101 were cancelled in 56 countries during the first six months of the pandemic), outreach services and surveillance. One deadly, highly infectious virus—measles—is unforgiving of immunity gaps and is certain to resurge after the COVID-19 pandemic, with a resultant catastrophic impact on young lives. The precarious measles immunity gaps resulting from suspended immunization activities and delayed campaigns are an ominous precursor to a measles resurgence. Increased malnutrition, due to effects of this pandemic on food supplies for impoverished children, and interruption of vitamin A supplementation during campaigns, may lead to increased measles-related deaths.


The recently published global report card on measles-elimination progress attempts to paint a positive picture, celebrating the increase in global first-dose measles vaccine coverage from 72% to 86% during 2000–2019; a concurrent increase in global second-dose measles vaccine coverage from 18% in 2000 to 71% in 2019; and the estimated 25.5 million deaths from measles averted during this time period due to this increased coverage
A thorough data review, however, portends a grim future for measles. For the past decade, global first-dose measles-vaccine coverage stagnated at 85%, which has left nearly 20 million children in every annual birth cohort unprotected against measles. Second-dose coverage is inadequate to guarantee enduring immunity, and coverage is highly heterogeneous within and between countries. The inequitable risk of measles is perpetuated through immunization campaigns that regularly fail to reach children who have never received a vaccine against measles.


Measles virus is the most infectious virus on the planet. Its reproduction number of 12–18 (the average cases one case generates over the course of that case’s infectious period in a susceptible population) far exceeds that of other emerging viruses, including SARS-CoV-2 (which has a reproduction number of 2.5–3.5). Given this incredible transmissibility and the annual accumulation of immunity gaps, the measles resurgence that commenced during 2017 and affected countries in every World Health Organization Region during 2018 and 2019 was predictable. This epidemic led to an appalling, preventable death toll (Table 1). Within just four years, there was an increase of 130% in estimated deaths attributed directly to measles. Those deaths do not capture delayed fatalities from subacute sclerosing panencephalitis due to persistent infection with measles virus, or deaths resulting from the array of viral and bacterial infections that exploit measles virus infection–induced ‘immune amnesia