Why it matters that a Brazilian variant has been detected in Shelby County

Although a new strain of coronavirus has been detected in Shelby County, the head of the joint COVID-19 task-force virus sequencing group said Tuesday that it is the least worrisome of two worrisome Brazilian strains. 

Dr. Manoj Jain, who oversees and coordinates the efforts in Shelby County to genetically sequence 100 random positive tests a week, said the University of Tennessee Health Science Center has identified the Brazilian variant known as P.2, which is similar to the P.1 variant that is also from Brazil.

While the presence of any coronavirus variant in Shelby County is worrying to local experts, Jain explained that scientists believe that P.2 variant is harder to spread than the P.1 variant — a good thing. The two variants share two common negative traits, however.

It is likely, scientists believe, that the Brazil variants cause reinfection, meaning that those who have already had the virus in Shelby County would need to be vaccinated. The antibodies they have from their previous infection won't stop them from getting the virus again.  And existing vaccines aren't particularly effective against the two Brazilian variants and one that is common in South Africa. 

"It does not appear to be that highly transmissible... It just doesn't have that level of transmissibility. It has that level of resistance to the vaccine and [causes] reinfection," Jain said. 

The specter of reinfection means that 80,000-plus people who have recovered from COVID-19 in Shelby County would have to be vaccinated with a shot that is effective against the var. If vaccine-resistant strains take hold in Shelby County, and the U.S., that would make the path to herd immunity, and normalcy, much longer. 

However, the lower level of transmissibility is a very good thing for the public, Jain explained. That means that it will take longer for the virus to spread, keeping the region's transmission number, known as Rnaught, down.

The transmission number is how many new infections, on average, each infected person leads to. A number below 1 means the epidemic is shrinking in Shelby County. For the past month, the Shelby County transmission number has been below 1, according to COVID Act Now. That has allowed the winter surge of cases that nearly overwhelmed Memphis hospitals to subside. 

The identification of the P.2 variant makes it the second mutant strain in Shelby County.

UTHSC has already identified the UK variant of novel coronavirus, which is more transmissible than the original strain of the virus that is prevalent and spreading throughout Shelby County. However, early data suggests that vaccines are effective against both the common strain and the UK variant. 

Strains could be contained

Without the vaccine as a tool against P.2, the Brazilian variant known to be in Shelby County, its relative P.1, and the South African variant, it is critical that Memphis and Shelby County don't let those strains reach the stage of community transmission.

If they do, the pandemic could linger for months or years in Shelby County until there are booster vaccines against those strains. The main weapon against the strains is the sequencing that Jain and Dr. Colleen Jonsson, the head of the biocontainment lab at UTHSC, are working on. 

If early cases of the strains are found, isolated and the infected person's contacts are traced, it's possible to forestall community transmission. 

Shelby County randomly sequences 100 positive tests a week and has since January. In late-January, according to NPR, the state of Minnesota was randomly testing 50 samples per week.

 In early January, scientists raised the alarm about the lack of nationwide surveillance system in the New York Times. Shelby County, and its preemptive sequencing, appears to be an outlier. That system might help the city and county stall or prevent community transmission of the variants. 

"We want to keep it down to the level of clusters or individuals," Jain said. 

But how likely is that? 

 "I think it's hard to tell. It's dependent on several key factors," Jain said. "The number of individuals who get vaccinated and how fast we get the vaccine out, because that will protect a larger number of people from the UK strain." 

Is herd immunity in 2021, and some semblance of normalcy, still possible? 

"The achievement of herd immunity is still something that's doable. If, at the same time  we do not allow the mutant strains, especially the ones that the vaccines are less effective [against] to become community transmission," Jain said. "If surveillance systems and other systems can quickly pick up the mutant virus, and then we isolate, like we do with cases of measles, obviously, and Ebola. If we can do that... we will still be able to achieve herd immunity." 

Samuel Hardiman is a watchdog reporter who covers Memphis City Hall, politics and the pandemic response for The Commercial Appeal. He can be reached by email at samuel.hardiman@commercialappeal.com or followed on Twitter at @samhardiman.