Temporal and spatial distribution trends of polio vaccine coverage in less than one-year old children in Brazil, 2011-2021.

BACKGROUND: Low polio vaccine coverage can result in the spread of Poliovirus to areas free from viral circulation. This study analyzed the temporal trends and spatial distribution of polio vaccine coverage in one year-old children in Brazil, between 2011 and 2021. METHODS: This was an ecological, time-series study (2011 to 2021) with annual vaccine coverages against poliomyelitis, extracted from the Information System of the National Immunization Program from the 26 States and the Distrito Federal (DF). The percentage reductions in vaccination coverage in Brazil and in the Regions were calculated. Prais-Winsten regression models were used to analyze time series for the Regions and States, and spatial analysis identified the distribution of clusters (high-high; low-low; high-low and low-high) of vaccination coverages across Brazilian municipalities, using a 5% significance level. RESULTS: From 2011 to 2021, the coverage of polio vaccines decreased by 29,9%. There was a progressive increase observed in clusters resulting in low vaccination coverages (140 low-low Brazilian municipalities in 2011 vs. 403 in 2021), mostly reported in the North and Northeast regions of the country. There was a downward trend in vaccination coverages in 24 of the 26 States and DF (p ≤ 0.05). CONCLUSIONS: The reduction in polio vaccine coverage, as observed in the North and Northeast regions of Brazil, may favor the spread of Poliovirus. Therefore, vaccination strategies should be prioritized for children residing in areas with sharp and recurrent declines in vaccination coverages, including travelers, migrants, and refugees.

Impact of COVID-19 pandemic on vaccination against meningococcal C infection in Brazil.

Objective: Analyzing the impact of COVID-19 pandemic on meningococcal C conjugate vaccination in Brazil. Methods: Ecological study, based on interrupted time series, carried out with data collected through the Information System of the National Immunization Program (IS-NIP). Collected data refer to the number of meningococcal C conjugate vaccine doses administered from March 2019 to December 2020. Results: In total, 14,832,054 meningococcal C conjugate vaccine doses were administered throughout the investigated period; 66.30% of them, from March 2019 to February 2020 and 33.70%, from March to December 2020. Statistically significant steps were observed, i.e., the COVID-19 pandemic had negative impact on the number of MenC vaccine doses administered in the North and South regions (26,98% and 41.47%, respectively) and in the eleven Brazilian States. Conclusion: The current study has shown that the COVID-19 pandemic had negative impact on the number of MenC vaccine doses administered in the Northern and Southern Brazil, and in eleven Brazilian states. Among all challenges experienced during the COVID-19 pandemic, one finds reduced MenC vaccine coverage, which, consequently, may lead to increased meningococcal infection rates in Brazil.

Number of doses of Measles-Mumps-Rubella vaccine applied in Brazil before and during the COVID-19 pandemic.

BACKGROUND: Due to the social isolation measures adopted in an attempt to mitigate the risk of transmission of SARS-CoV-2, there has been a reduction in vaccination coverage of children and adolescents in several countries and regions of the world. OBJECTIVE: Analyze the number of doses of vaccine against Measles-Mumps-Rubella (MMR) applied before and after the beginning of mitigation measures due to COVID-19 pandemic in Brazil. METHODS: The data collected refer to the number of doses of the MMR vaccine applied monthly to the target population residing in Brazil: cahildren, aged 12 months (first dose) and children, aged 9 years (second dose), from April 2019 to December 2020. Differences in MMR vaccine doses from April 2019 to March 2020 (before the start of mitigation measures) and April 2020 to September 2020 (after the start of the mitigation measures) were evaluated. Spatial analysis identified clusters with a high percentage of reduction in the median of applied doses no Brazil. RESULTS: There was a reduction in the median of doses applied in the Regions North (- 33.03%), Northeast (- 43.49%) and South (- 39.01%) e nos Estados Acre (- 48.46%), Amazonas (- 28.96%), Roraima (- 61.91%), Paraíba (- 41.58%), Sergipe (- 47.52%), Rio de Janeiro (-59.31%) and Santa Catarina (- 49.32) (p < 0.05). High-high type spatial clusters (reduction between 34.00 and 90.00%) were formed in the five regions of Brazil (Moran's I = 0.055; p = 0.01). CONCLUSION: A reduction in the number of MMR vaccine doses was evidenced as a possible effect by the restrictive actions of COVID-19 in Brazil.