Lingering questions around Brazil’s vaccination plan

. Jan 18, 2021
vaccine doria brazil bolsonaro Governor João Doria of São Paulo championed the Chinese-made CoronaVac. Photo: Govesp

As Brazilian federal health regulator Anvisa issued emergency approval for 6 million doses of the Chinese-made CoronaVac and 2 million of AstraZeneca’s vaccine, its board members detailed exactly what they analyzed in the data provided by each laboratory. And while the regulatory approval is a landmark in Brazil’s fight against the pandemic, there remains a long way to go before both vaccines get unrestricted authorization for use and distribution.

Gustavo Mendes, in charge of Anvisa’s medication safety department, recommended that regulators “keep a very close eye on the uncertainties [around each vaccine] and constantly reassess their development.” He continued: “If we don’t monitor it closely enough, we risk never knowing the real and full data [of each vaccine’s efficacy].”

He listed 14 “uncertain points and risks” around CoronaVac, produced by the Shanghai-based Sinovac Biotech group, and 11 about AstraZeneca’s vaccine, developed by the University of Oxford.

We break them down:

</p> <h3>Uncertain points around the CoronaVac</h3> <ul><li>Lack of data around long-term immunity;</li><li>Doubts around how efficient single doses are;</li><li>Uncertainty concerning how safe the vaccine is for people previously contaminated with the coronavirus;</li><li>Lack of data on how efficient the vaccine is on people with a previous Covid-19 infection as opposed to those who were never contaminated;</li><li>The amount of senior citizens who participated in the study was deemed &#8220;insufficient;&#8221;</li><li>It remains unclear what the ideal interval between the two shots is;</li><li>Phase 3 trial data doesn&#8217;t clearly show how many participants needed intensive care —&nbsp;neither among those who took the vaccine or those who took the placebo;</li><li>Lack of descriptions of all deviations from protocol for each volunteer;</li><li>There is a need to specify all positive cases involved in the trials;</li><li>There is no proof of the efficacy of the vaccine in children, people with pre-existing conditions, pregnant women, and immunodeficient individuals.</li></ul> <h3>Uncertain points around the AstraZeneca vaccine</h3> <ul><li>There are questions about how does the vaccine produced in the United Kingdom compare to that being produced in India;</li><li>Not enough information on antibody assessments;</li><li>Children, people with pre-existing conditions, pregnant women, and immunodeficient individuals were not included in the trials;</li><li>The amount of senior citizens who participated in the study was deemed &#8220;insufficient;&#8221;</li><li>It remains unclear what the ideal interval between the two shots is;</li><li>Safety and efficacy remain under analysis as trials are ongoing;</li><li>Insufficient data on the vaccine&#8217;s effectiveness against severe Covid-19 infections — even if the available data suggests favorable results;</li><li>Insufficient data on the possibility of applying a single shot on patients;</li><li>Mistakes in administering the first dose must be taken into account;</li><li>Lack of high-quality documentation on the detection of viral particle concentration.

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Débora Álvares

Débora Álvares has worked as a political reporter for newspapers Folha de S.Paulo, O Estado de S.Paulo, Globo News, HuffPost, among others. She specializes in reporting on Brasilia, working behind-the-scenes coverage at the Executive, Legislative, and Judiciary branches of government.

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