A new and yet un-reviewed study has found that there might be a link between contracting dengue that provides some sort of immunity against the Coronavirus to people.
The study has been conducted by researchers from the University of SÃ£o Paulo in Brazil and Duke University, US, but has yet to be peer-reviewed and published. The authors of the study have shared an exclusive with Reuters and it was published on the MedRxiv preprint server and is going to be submitted to a scientific journal.
Dengue is a viral disease that spreads through the bite of an Aedes mosquito, usually in tropical and subtropical regions. If you are bitten by an infected mosquito, the symptoms can take up to two weeks to develop but usually lasts less than a week.
The study is being led by Miguel Nicolelis, a professor at Duke University. They proposed that people who have fallen ill with a mosquito-transmitted illness like dengue might have some immunity towards the virus. To find out if there is any truth in this hypothesis, they used mathematical modelling to understand what is causing the 'uneven spread' of Covid-19 in Brazil and compared the 'geographic distribution' of COVID-19 cases with the spread of dengue in 2019 and 2020.
They found that cities with lower coronavirus infection rates and slower case growth coincided with cities that had suffered intense dengue outbreaks in 2019-2020. These cities also took a long time to 'reach exponential community transmission, due to slower SARS-CoV-2 infection growth rates.' According to a report by The Print, they also found that, during the first three months of the pandemic, about 17 'super-spreading' cities accounted for up to 99 percent of the Covid-19 cases in Brazil.
Reuters reported that the study says, "This striking finding raises the intriguing possibility of immunological cross-reactivity between dengue's Flavivirus serotypes (dengue antibodies) and SARS-CoV-2."
"If proven correct, this hypothesis could mean that dengue infection or immunisation with an efficacious and safe dengue vaccine could produce some level of immunological protection."
It would also mean that dengue vaccine, that has already been tested to be safe and effective, could provide some form of immunisation against the virus. At least, until the efficacy of a COVID-19 vaccine is tested.
According to The Print report, this study could be important for India because our country battles dengue outbreaks every years and so do many other countries.
This is not the first time that a study has found links between dengue providing immunity against COVID-19. According to a report by The Hindu, two studies conducted by a group in Israel and another conducted by the Council of Scientific and Industrial Research-Indian Institute of Chemical Biology (CSIR-IICB) in Kolkata also came to similar conclusions.
They showed that tests used to check for dengue could lead to a positive SARS-CoV-2 result. They also suggested that further studies need to be conducted into whether the structures of the dengue virus and Coronavirus have some similarities.