Potential Link between Anti Malaria Prophylaxis and the Prevention of COVID-19 Infection. Chloroquine!

Potential Link between Anti Malaria Prophylaxis and the Prevention of COVID-19 Infection

Potential Link between Anti Malaria Prophylaxis and the Prevention of COVID-19 Infection

Potential Link between Anti Malaria Prophylaxis and the Prevention of COVID-19 Infection

Irene Guerrini1 2 and Modupe Oshadiya =2 1South London and Maudsley NHS Trust, London, UK and 2Kings College, London, UK. Address correspondence to Irene Guerrini – E-mail: irene.guerrini01@googlemail.com

We suggest a potential link between anti-malaria prophylaxis and the prevention of the novel COVID-19 infection, supported by a known pharmacological mechanism.

We looked at the worldwide distribution of malaria and of the COVID-19 infection. Maps below (Fig. 1) offer the tantalising suggestion of a geographical separation, with countries affected by malaria mostly being clear of COVID-19 (blue=death rate of more than 0.1 malaria deaths per million inhabitants), and vice-versa countries that have suffered COVID-19 mostly being also where malaria is not active (orange=death rate of more than 0.1 COVID-19 deaths per million inhabitants).

Figure 1 – Blue/Yellow countries where respectively Malaria (top) and COVID-19 (bottom) have caused more than 0.1 deaths per million inhabitants (sources: Ourworldindata.org (Malaria) and Worldofmeters.info (COVID-19), 14 March 2020)

Assuming that malaria prophylaxis be active in the countries affected by it (i.e. with a larger death rate), this would show that it inversely correlates with the number of COVID 19 deaths. In other words, there is a clear basis for our group to hypothesise a potential link between anti malaria prophylaxis and the prevention of the novel coronavirus infection.

We propose the following underlying reason: chloroquine and its analogues are an effective preventive treatment for malaria, and it is widely used for prophylactic purposes mainly in the sub-Saharan zones. As Vincent and co-workers (2005) indicated, chloroquine seems to have a strong antiviral effect on SARS-CoV in an in vitro primate cells study. Several trials conducted in China on the Covid-19 have also showed that chloroquine and hydroxychloroquine improved the symptomatology and the outcome of the infection (Todaro & Rigano, 2020); Touret & De Lamballerie, 2020; Yao X et al. 2020; Wang M et al. 2020). Wang and co-workers (2020) suggest chloroquine “should be assessed in human patients suffering from the novel coronavirus disease”.

Vincent and co-workers (2005) postulated that chloroquine interferes with terminal glycosylation of the angiotensin-converting enzyme 2, the cellular receptor of the SARS-CoV, and suggested the potential use of chloroquine as a prophylactic and therapeutic pharmacological intervention in humans. Todaro & Rigano (2020) also write that “In the case of chloroquine treatment prior to infection, the impairment of terminal glycosylation of ACE2 may result in reduced binding affinities between ACE2 and SARS-CoV spike protein and negatively influence the initiation of SARS-CoV infection”.

The above is compatible with a geographical distribution with a pattern similar to what shown in Figure 1: areas with anti-malarial prophylaxis would be naturally protected

We would like to encourage the scientific community to further investigate the use of chloroquine-based medications as a preventative intervention to halt the spread of the COVID-19 infection, and the possibility of massive prevention/early intervention campaign with wide distribution of chloroquine to those at risk of infection, or already infected.

This analysis has several biases which might justify the regional differences, data reporting systems, biological and environmental factors.

We would like to thank Maurizio Morabito of Omnologos Ltd for helping with the data visualisation.


Wang, M., Cao, R., Zhang, L. et al. Remdesivir and chloroquine effectively inhibit the recently emerged novel coronavirus (2019-nCoV) in vitro. Cell Res 30, 269–271 (2020).

Vincent MJ, Bergeron E., Benjannet S. et al. Chloroquine is a potent inhibitor of SARS coronavirus

infection and spread. Virol J. 2005;2:69

Yao X, Ye F, Zhang et al., In vitro Antiviral Activity of Optimized Dosing design of Hydroxychloroquine

for the treatment of severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). Clin Infect Dis.

2020 Mar 9

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