Covid-19: The lack of vaccine trial data creates another layer of inequality

Vaccines are being rolled out in Latin American for which we have little information beyond press releases

The covid-19 vaccine race has highlighted the importance of the equitable distribution of resources worldwide for ethical and epidemiological reasons. It is not fair to vaccinate individuals at low risk of complications and death from covid-19 in high income countries, while people at high risk from covid-19 in low middle income countries are not expected to receive the vaccine in the near future. Letting the virus run free in low and middle income (LMIC) countries also allows it to mutate and potentially generate the feared “variants” that may escape vaccine-mediated immune responses.

Some attempts to reduce inequalities in the distribution of vaccines include ramping up global production, suspending the enforcement of intellectual property rights, and promoting vaccine exchange and redistribution, especially from countries that have purchased an immoral surplus of vaccine doses. [1,2] Among these initiatives, COVAX (the vaccine initiative co-led by the Coalition for Epidemic Preparedness Innovations [CEPI], Gavi, the World Health Organization [WHO], and UNICEF) aims to reduce these inequalities by linking funders and manufacturers and advocating on behalf of LMICs. [3] By 25 March 2021, COVAX had distributed over 32 million doses to 60 participants of their initiative, including several Latin American countries: Bolivia, El Salvador, Colombia, Brasil, Paraguay, Ecuador, Jamaica, Nicaragua and Honduras. [4] These vaccines primarily include the Pfizer-BioNTech and Oxford/AstraZeneca vaccines. 

The rollout of vaccines in Latin America, however, poses additional challenges due to the pre-existing political, economic, and social crises. These include the social unrest in Chile that led to a plebiscite vote in favour of changing their constitution, the severe financial crisis in Argentina that worsened the country’s debt situation and currency devaluation and led to change of government, and the political crisis in Brazil that led to the election of the right-wing populist leader Jair Bolsonaro. The response to covid-19 in these countries has been under national and international scrutiny, especially in Brazil, where Bolsonaro’s denial of the covid-19 pandemic and the escalating crisis is causing international concern. Nevertheless, the covid-19 vaccine rollout started in Latin America (mostly in Chile and Argentina) at the end of 2020, primarily due to direct agreements between national governments and vaccine manufacturers.

The deployment of the Pfizer-BioNTech and Oxford/AstraZeneca vaccines in Latin America has generally been well received because international regulators like the US Food and Drugs Administration (FDA) and the European Medicines Agency (EMA) have approved the vaccines and provided open access to evidence about their assessments. However, one of the first issues appeared early in the year when scientists in Argentina pointed out the lack of information about the interim results of the phase III trial of the Sputnik V vaccine. The first doses of the Sputnik V vaccine have already been distributed between December 2020 and January 2021. The only publicly available data were via a press release by the Gamaleya Institute and a two-page report by the Argentinian regulatory agency (ANMAT), claiming that the results were under embargo by a journal. [5] While some of these concerns were reduced with the publication of the phase III trial results in The Lancet in early February, the full protocol has not been released, and the regulators have not issued an independent evaluation. [6] Moreover, The Lancet allows the publication of data that have already been published on the author’s website, or as a preprint. [7]

In the context of an ongoing “second wave” and the uncontrolled spread of variants, including the P1 variant from Manaos that is causing the collapse of the healthcare system in Brazil, the regulators in Latin America have authorised the use of two Chinese vaccines: Sinopharm and Sinovac’s Coronavac. These are being rolled out in  Argentina, Bolivia, Peru; and Chile and Brazil, respectively. [9-13] Argentina’s regulatory agency also approved the use of the Sinopharm vaccine in people over the age of 60 based on the neutralising antibody response data provided by the manufacturer. [14] By using these vaccines for which there are no publicly available technical reports on the interim analysis of the phase III trials nor published data, some countries are leading the vaccine race in Latin America. Additionally, there is little or no information about the effects of these vaccines in patients’ subgroups or whether their effectiveness might be impaired by variants, which is important considering that their efficacy for the original strain could be as low as 50%. [15]

The lack of publicly available data on these vaccines adds another layer of inequality: we are administering vaccines to millions of individuals in Latin American countries for which we have little to no information beyond press releases. This would not be acceptable for high-income countries who sign deals with the main manufacturers and align their regulators’ power to guarantee quality control and transparency in the approval process, even in the most sensitive cases, as with the AstraZeneca vaccine and the incidence of adverse events. [16] Furthermore, each LMIC country alone is not sufficiently powered to negotiate access to other vaccines for which there are more transparently available data amid a brutal fight over vaccine doses. International collaborations are needed, with the support of multilateral organisations such as WHO/PAHO to ensure that all vaccine data become available as soon as possible. National governments will still have to make tough decisions related to the use of vaccines with lower efficacy, the number and spacing between doses, and prioritising who should get the vaccines first, but this must be done with publicly available data and wide consultation to relevant stakeholders. We cannot afford to fuel anti-vaxxers, conspiracy theorists, and covid-deniers in countries that are struggling to ramp up vaccination during a global crisis.

Juan Víctor Ariel Franco is the editor-in-chief BMJ Evidence-Based Medicine and a professor at the research department at the Instituto Universitario Hospital Italiano de Buenos Aires (Argentina).

Twitter handle: @juan_francomd

Competing interests: none declared (full statement available here)

Acknowledgement: I would like to thank Eva Madrid (Chile) and Karin Kopitowski (Argentina) for revising the manuscript and providing feedback.


1 Covid-19: A call for global vaccine equity – The BMJ. 2021. (accessed 26 Mar 2021).

2 The race for covid-19 vaccines: we must distribute vaccines equitably around the world – The BMJ. 2021. (accessed 26 Mar 2021).

3 Strategy. (accessed 26 Mar 2021).

4 COVAX vaccine roll-out. (accessed 26 Mar 2021).

5 Informe de la ANMAT sobre la vacuna Sputnik V. 2020. (accessed 26 Mar 2021).

6 Logunov DY, Dolzhikova IV, Shcheblyakov DV, et al. Safety and efficacy of an rAd26 and rAd5 vector-based heterologous prime-boost COVID-19 vaccine: an interim analysis of a randomised controlled phase 3 trial in Russia. Lancet 2021;0. doi:10.1016/S0140-6736(21)00234-8

7 The Lancet. (accessed 26 Mar 2021).

8 Brazil, a country collapsing during the covid-19 pandemic – The BMJ. 2021. (accessed 26 Mar 2021).

9 Argentina approves Sinopharm COVID-19 vaccine for emergency use. Reuters. 2021. (accessed 26 Mar 2021).

10 Bolivia signs deal with China´s Sinopharm for coronavirus vaccine. Reuters. 2021. (accessed 26 Mar 2021).

11 Peru inks deals with Sinopharm, AstraZeneca for coronavirus vaccines -president. Reuters. 2021. (accessed 26 Mar 2021).

12 Chile regulator greenlights Sinovac COVID-19 vaccine for emergency use. Reuters. 2021. (accessed 26 Mar 2021).

13 Brazil approves use of CoronaVac doses partly manufactured locally. Reuters. 2021. (accessed 26 Mar 2021).

14 Anmat autorizó la vacuna Sinopharm en los mayores de 60 años. (accessed 26 Mar 2021).

15 Mallapaty S. China COVID vaccine reports mixed results – what does that mean for the pandemic? Nature Published Online First: 15 January 2021. doi:10.1038/d41586-021-00094-z

16 Covid-19 vaccine adverse events: balancing monitoring with confidence in vaccines – The BMJ. 2021. (accessed 26 Mar 2021).