Impact of the SARS-CoV-2 Pandemic on Vaccine Preventable Disease Campaigns

Background: The COVID-19 pandemic has contributed to a widespread disruption of immunization services, including the suspension of mass vaccination campaigns. Methods: In May 2020, the World Health Organization (WHO) and partners established an Immunization Repository Campaign Delay Tracker to document the COVID-19 related disruptions to preventive and outbreak response vaccination campaigns worldwide of nine vaccines. Data were collected from disease specific initiatives that provided programme information to WHO Headquarters and reported through the Polio Information System (POLIS). Using these data, the authors reviewed the number of vaccination campaigns that were scheduled, postponed, cancelled and reinstated at three timepoints: May 2020, December 2020 and May 2021. Findings: The results indicate that mass vaccination campaigns across all vaccines were disrupted heavily by COVID-19. In May 2020, 105 of 183 (57%) campaigns were postponed or cancelled in 57 countries due to COVID-19, which resulted in an estimated 796 million postponed or missed vaccine doses. Campaign resumption was observed beginning in July 2020. By May 2021, 56% (72 of 128) postponed campaigns had been reinstated after an initial postponement due to COVID-19. However, 79 campaigns in 53 countries were still postponed or cancelled due to COVID-19, which resulted in an estimated 390 million postponed or missed vaccine doses. Interpretation: Our findings suggest a high risk of an increased number of persons susceptible to vaccine-preventable diseases during the pandemic due to mass vaccination campaign postponement. Implementing safe, aggressive and innovative catch-up vaccination strategies is needed to prevent sizeable vaccine-preventable disease outbreaks resulting from these accumulated immunity gaps. Funding Information: This study is not supported by any funder. Declaration of Interests: We declare no competing interests.