Covid-19 , the anti-vaccine movement and immunization challenges in Brazil : a review

AIMS: The COVID-19 pandemic suddenly and significantly increased hospitalizations for pneumonia with systemic inflammatory disease. Since its appearance, COVID-19 has affected more than 200 countries, with more than 90 million cases and almost 2 million deaths. So far, there is no quality evidence regarding the specific pharmacological therapy for COVID-19; most treatments usually involve off-label use of existing drugs and have unproven efficacy. The global effort converges on the development of a vaccine; however, the greatest challenge is to achieve collective immunization in the face of increasing vaccination hesitancy.


INTRODUCTION
In December 2019, several cases of pneumonia due to an unknown cause were reported in Wuhan Since its emergence, COVID-19 has affected more than 200 countries, resulting in more than 90 million cases and almost 2 million confirmed deaths and the numbers keep on increasing (2).
Treatment involves supportive therapy such as isolation, rest, oxygen therapy, antibiotics for secondary bacterial infections, anticoagulants and corticosteroids (3,4).
The global effort converges not only in the search for an efficient drug, but also in the development of a vaccine that can induce immune memory.
However, the challenges of vaccination make it difficult to achieve group or collective immunity (5). Active immunization through vaccination is an effective mechanism for the prevention of infectious In recent years, a significant portion of the population has demonstrated hesitancy and/or hesitation to use vaccination as an immunopreventive measure despite the fact that immunization is effective and safe. In connection with this, instability and delays in vaccinations have led to low levels of vaccination coverage and consequently, to the increase in the incidence of previously eradicated diseases. One example is the measles epidemic which is afflicting Brazil again (7). The challenges of immunization arise mainly from the antivaccine movement that has been gaining prominence in the United States, Brazil, and the world (8). A study on the intention of the population to vaccinate against H1N1 in the United States showed that at the beginning of the pandemic in 2009, the intention was about 50% but decreased considerably to 16% in the following year, January 2010. This demonstrates the low adherence of the population to vaccination (9).
According to the Brazil Ministry of Health, vaccination coverage rates for polio and measles during the 2018 vaccination campaign reached around 40%, much less than the ideal value set by the WHO, which was at least 95%. Parents who had not been exposed to these diseases did not take them seriously and chose not to vaccinate their children. This revealed that the adult population possibly misinterpreted vaccination and followed their own instinct. Studies proposed that the increased number of some preventable diseases result from heterogeneity of vaccination coverage, and that unvaccinated individuals tend to interact with each other, creating subpopulations that are susceptible to new local outbreaks; people who hesitate vaccination also tend to be close with each other (10).
In this sense, the best scientific evidence demonstrates that the elimination and/or control

Study Description
The research method used in this study was integrative bibliographic review with qualitative method approach.

Data Research and Analysis Procedure
To carry out this literature review, the precepts of the exploratory study were followed through an The selection of articles was carried out by three independent evaluators, after which they met and checked if there was a difference of opinion, and these were resolved through a consensus.
The selection was initially made through titles, followed by abstracts, and when selected, by a complete reading of the articles. For the exclusion criteria, all studies that did not fit the theme or objectives addressed and studies that did not fit the article modality (such as theses, monographs, reviews, and abstracts) were excluded. Articles that were not free and/or not available in their full format were also not added.

RESULTS AND DISCUSSION
In the proposed manner, the electronic search  Table 1 for PubMed and Table 2 for SciELO.   (13). One of the strategies for speedy vaccine production is knowledge of viral antigens, which makes it possible to synthesize the vaccine more quickly without using inactivated virus (14). In a UK study, parents who believed in anti-vaccine conspiracy theories were less likely to vaccinate a child (25). In Brazil, the movement has been gaining strength.

FINAL CONSIDERATIONS
It is well known that the advance of antivaccine thinking leads to an increased risk of resurgence of previously eradicated diseases.
There are conspiracy theories around the world from developed to developing countries. In Brazil,

Notes Funding
This study did not receive financial support from external sources

Conflicts of interest disclosure
The authors declare no competing interests relevant to the content of this study.

Authors' contributions.
All the authors declare to have made substantial contributions to the conception, or design, or