The number of Iowa children receiving vaccinations dropped by more than half during the novel coronavirus pandemic when compared to last year, prompting concern among officials for outbreaks of vaccine-preventable disease.The Iowa Department of Public Health released a new report Friday that details the rate of non-influenza immunizations — such as vaccines for measles, mumps and rubella or polio — for Iowa children and adults.The report notes the decline in vaccinations may be the result of mitigation efforts for the novel coronavirus.