The percentage of people vaccinated in Brazil has decreased since the COVID-19 pandemic. Health officials say the situation has put millions of people at risk of being infected with diseases that have been under control in Brazil. Doctors, government agencies and the United Nations Children’s Agency, UNICEF, have tried to bring attention to the issue. Official government records show that in 2015, vaccination coverage in Brazil was 95 percent. But that number fell to 68 percent last year. For polio, vaccinations dropped from 85 percent to 68 percent. Officials are warning that polio could return to Brazil, where it had been eradicated in 1989. Similar decreases in vaccinations have been recorded for other diseases. The disease measles was declared eradicated from Brazil in 2016. But it returned two years later. And there are fears that diphtheria could be coming back too. Health experts say the reduction in vaccinations is a growing problem worldwide. But the drops are especially worrying in Brazil, a country of 203 million people that until recently was seen as a leader in nationwide vaccination campaigns.