In-Depth: What we know about the Brazil variant

Much of our understanding comes from Manaus
Virus Outbreak Variant
Posted at 6:06 PM, Mar 25, 2021
and last updated 2021-04-18 21:41:51-04

SAN DIEGO (KGTV) -- Now that two cases of the Brazil variant have been detected in San Diego County, a lot of people have questions.

Is the variant more contagious? Is it more deadly? How effective are the vaccines against it?

Much of our current understanding of the Brazil variant comes from a city in the center of the Amazon Rainforest: Manaus.

Early in the pandemic, the original version of the virus swept through the city of roughly 2.2 million. After a peak in April, cases declined and stayed low for months. By October, one study estimated 76 percent of the city’s population had antibodies, what they thought was enough for herd immunity.

But in December, scientists detected a variant in the city called P.1 that had several mutations in its spike protein. Hospitalizations surged.

“They actually had more hospitalizations and more cases than even the first wave,” said Dr. Christian Ramers of Family Health Centers of San Diego. “So it's a real cautionary tale, suggesting that people that had gotten COVID before were now able to be reinfected by this new strain.”

Using data from Manaus, a team of British and Brazilian researchers estimated this month the P.1 variant could be up to two times more transmissible than the original strain, a claim the Centers for Disease Control and Prevention and the World Health Organization have not yet endorsed.

The same study also looked into whether the variant caused more severe disease and deaths. While noting there was an uptick in mortality, the researchers said they couldn’t conclude the variant itself was more deadly because the local healthcare system in Manaus collapsed amid the surge.

However, the CDC and other health authorities agree the Brazil variant has mutations in its spike protein that appear to make it more resistant to our current antibody treatments and convalescent plasma, and more resistant to vaccines.

We don’t know much about the impact to the Pfizer and Moderna vaccines because they were tested before variants emerged, Dr. Ramers said, but Johnson and Johnson is another story.

“The Johnson and Johnson trial was run in South Africa, in North America and in South America, largely Brazil,” he said. “So we have actual clinical data of how good this vaccine is in context where this Brazil variant is circulating, and it's really pretty darn good.”

Johnson and Johnson’s overall effectiveness dropped modestly from 72 percent in the U.S. to 68 percent in Brazil.

However, its effectiveness against severe disease in Brazil was 87.6 percent.

“So it gives us really good confidence that this vaccine will protect against the Brazil variant,” Ramers said.
Dr. Ramers said if he had to rank the variants, he’s more concerned about the one first detected in South Africa, B.1.351.

According to the CDC’s latest data, there have only been four known cases of B.1.351 in California, along with four known cases of the Brazil variant.

With so few cases, scientists say we can still prevent those variants from taking off -- if we keep vaccinating quickly.