By Patricia Nieto Mariño, Waldheim Garcia Montoya, Jorge Gil and Monica Martinez
Santiago/Sao Paulo/Bogota/Lima, Sep 15 (EFE).- The highly contagious Delta variant set off alarm bells worldwide and in a matter of months became the dominant form of the coronavirus, yet for now it accounts for only a minority of cases throughout much of Latin America.
Competition among different variants, a diversified vaccine strategy and climatic factors are some of the hypotheses put forth by experts to explain this phenomenon.
With nearly 44 million confirmed coronavirus cases and 1.46 million deaths attributed to Covid-19, Latin America has been one of the hardest-hit regions from both a medical and economic standpoint.
But with the exception of Mexico, where the Delta variant now predominates, that variety has not spread like wildfire the way it did in regions like Europe and Asia that in just weeks reported millions of new cases.
Since the first Delta variant case was registered in June, Chile has seen a steady drop in new confirmed cases and is now experiencing a Covid-19 respite and an easing of restrictions on personal freedoms.
The director of Chile’s Public Health Institute, Heriberto Garcia, says climate may have played a role, noting that it was winter in the Southern Hemisphere at the time the Delta variant was quickly spreading during the European summer.
Another reason it has spread less readily is “competition” among Latin America’s different coronavirus variants, Fernando Donaires – director of the National Public Health Center, a division of Peru’s National Health Institute – told Efe.
Peru has reported more than 2 million coronavirus cases since the onset of the pandemic, yet according to the government’s latest figures there have only been 244 Delta variant cases to date.
A different coronavirus variant known as Lambda – first detected in the Andean region in April – has been a much bigger driver of the health emergency there, accounting at one point for 80 percent of new Covid-19 cases.
Similar situations have occurred in Colombia, where the Mu variant was the driver of a third coronavirus wave between April and August, and in Chile, where the Gamma variant remains the most common form of the coronavirus and the Mu variety now accounts for more cases than the Delta one.
“It’s one of the possibilities that could be slowing down the transmissibility of this variant,” Donaires told Efe, though adding that it is feasible that the Delta variety will start spreading more quickly.
Unai Tupinambas, an infectious disease specialist at Brazil’s Federal University of Minas Gerais, added that the scant spread of the Delta variant is “intriguing” and could be attributable to a “cross-reaction” with other coronavirus varieties.
That could partially explain why the Delta variant’s impact in Brazil was not as strong as initially feared and why its nationwide prevalence fell from 61 percent in early August to 35 percent two weeks later, he told Efe.
According to Dr. Flavio Salazar, the University of Chile’s vice president for research and development, immunization has been “key” to avoiding further coronavirus outbreaks, as has been the necessity-driven use of a variety of vaccines from different laboratories.
Salazar noted in particular that China’s Sinovac, a traditional inactivated vaccine, is able to neutralize a wider range of variants than mRNA vaccines like the one developed by Pfizer/BioNTech.
He said that would explain why the Delta variant caused renewed outbreaks in Israel, a country with a very high percentage of the population vaccinated but where only Pfizer’s jab was administered.
Even so, the epidemiology coordinator at Bogota’s Del Rosario University, Carlos Trillos, said the Delta variant could still cause a spike in cases.
“It’s going to keep growing. As we know, Delta is a much more contagious variant,” he told Efe. EFE