A new Fiocruz study focuses on Covid-19 vaccines for children as an important strategy to increase vaccine coverage for the Brazilian population. The research, submitted to the Brazilian Journal of Epidemiology and available as preprint, analyzes the evolution of vaccination in the country and observes that immunization in Brazil is likely to be reaching stagnation.

Currently 85% are eligible for the vaccine (all above 11 years of age). However, the researchers observed that since September last year first-dose vaccination has been slowing down. In the two months after October 9 this rhythm has been dropping more and more during each epidemiological week (EW), getting close to zero - about 0.08% per day. For the researchers, this may suggest that vaccination is nearing its limits, with 74.95% of the population having taken the first shot.  

According to the study, one of the ways to overcome this stagnation is to expand the age groups eligible for vaccination - immunizing children - and to create new strategies to increase first-dose administration to people who live in remote areas. For the researchers, this stagnation is more related to poor access than to a refusal to be vaccinated.

The analysis was based on vaccine coverage per Brazilian state, according to the epidemiological week, and using as reference the last day of each EW. The reference period used for the analysis was Epidemiological Week 47, corresponding to the last week of November.

According to the study, Brazil has four distinct phases in the time evolution for the application of the first dose. There was an initial phase during which progression was slow partly due to the lack of vaccines. It was followed by a period of about 10 weeks during which vaccination began to be applied to people below 70, then followed by another in which vaccine coverage gained speed and reached people below 60. Then came the fourth phase, with a clear deceleration.

“Most states follow this trend. What varies is the speed of vaccine coverage increase, which was systematically higher in the South and South-East regions”, comments Raphael Guimarães, researcher of the Fiocruz Covid-19 Observatory and one of the authors of the study. The researcher emphasizes that “in the states where coverage for the first dose is higher, the difference from the second shot is lower, suggesting that loss of population between doses has been small”.

The authors highlight that the states of the North have a younger population, which can explain, in part, the lower coverage in this area. The study shows great national inequality, with North and North-East with the worse coverage for first as well as second dose, showing clearly that Brazilian figures are inflated by the statistically higher numbers of the Center-South states. For instance: The states of São Paulo and Amapá have the highest and lowest vaccine coverage in the country, respectively. “It should be pointed out that in addition to populational aspects, issues related to the logistics of distribution can influence the data used in the analysis”, observes Guimarães.

The study mentions that the strategy of vaccinating people as a mitigation measure against the pandemic has been effective in Brazil and worldwide. In general, the population has been adhering to the vaccine. As for the vaccination of children, the authors say there are vaccines with proven effectiveness for this age group, as well as safety studies that show it is possible to use the vaccine in this age group.

According to specialists, vaccine compliance in Brazil is the result of40 years of building credibility regarding the country’s National Immunization Program, which ensures universal coverage for the Brazilian basic vaccination scheme. “In this sense, it is reasonable to presume that this stagnation is more related to difficulty accessing vaccines than to a refusal of vaccines”, says Guimarães. According to the analysis, vaccine coverage is lower in poorer areas and among groups of ethnic minitories. It is therefore crucial to strengthen strategies that are committed to reducing vaccine inequality.

Guimarães emphasizes that vaccination is an individual and collective responsibility. “It is also crucial to speed up the purchase of vaccines of proven safety for children between 5 and 11 years old, so this group is protected and therefore allows for a higher vaccine coverage in the country”.

Source: Fiocruz News Agency (AFN).