An immunological study and analysis of geographical spread have pointed out that there is a cross reactivity (serological) in between the Dengue virus and the Coronavirus. The study (which has not yet been published) by Professor Miguel Nicolelis of Duke University shared exclusively with the Reuters, performed a comparative analysis between the geographical spread of the Coronavirus disease with that of the Dengue virus disease for the years 2019 and 2020. It found out that the places which had virulent outbreaks of the Dengue had lower infection rates for the Coronavirus disease.

At a hypothesis level it indicates that with immunological response to the Dengue and a proper immunization with vaccine, a type of immunological shield can be provided against the COVID19. Earlier it has been found out that the people who had been infected with dengue, having the corresponding antibodies in their bodies have shown false positive result for COVID even with no prior cases of Covid infection. This becomes interesting as the two viruses are from totally different families. The Dengue belongs to the Flavivirus family and the Coronavirus belongs to the Coronaviridae family. The false positive detection for Covid in dengue infected people shows that there is a hitherto unknown type of immunological interaction of the two virus types. It might be that infection with the dengue leads the body to produce such antibodies (immunoglobulins) which may counter Covid virus.

Mortality, lower incidence, and growth rate of the Covid19 have a correlation in the population of Brazil, where there is a higher detected level of antibodies to Dengue. In the states in Brazil like Rio Grande do Sul and others where there is predominance of dengue cases, there Covid19 has taken a longer time to spread through community transmission, with respect to those states having lower number of Dengue cases.

It would be crucial to remember that last year, the south Indian states like Kerala, Karnataka, Telangana, Andhra Pradesh and Tamil Nadu had seen more than half of the Dengue cases registered in the country. The states despite having taken initiatives in IEC (Information, Education and Communication) through the Accredited Social Health Activist (ASHA) had see higher number of cases. Could the study point out that the number of COVID19 cases could have been much higher if the states had not seen higher prevalence of Dengue?

A 2015 study published in Experimental Biology and Medicine journal had pointed out that the infection with Dengue produces an Immunoglobulin- IgM. The study found out that the IgM antibodies produced in the body in the response to the Dengue infection is broad spectrum and cross reactive which recognizes intact virions. Another study published in June 2020 in Emerging Microbes and Infections journal had figured out that Covid infection at first produces IgM responses in the body after which there is a class-switch in the antibody response to IgG which is of high affinity type. If these studies are taken with the hints of cross reactivity found out by Prof. Miguel Nicolelis, they can provide a way for clearer understanding of the Covid infection and possible ways to counter it.