Scientists support Brazil’s attempt to ban the import of the Russian COVID vaccine “Sputnik V”

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Washington – Scientists supported the decision by the Brazilian Drugs Regulatory Agency to stop importing Russia’s Sputnik V. Coronavirus Vaccine, based on the batches they tested contained a live version of a cold virus. Top virologist Angela Rasmussen told AFP that the result “raises questions about the integrity of manufacturing processes” and could pose a safety issue for people with weaker immune systems if the problem is found to be widespread.

The Russian Gamaleya Institute, which developed the vaccine, has rejected the reports.

The problem revolves around an “adenovirus vector” – a virus that normally causes mild respiratory disease but is genetically engineered in vaccines so that it cannot replicate and edited to provide DNA instructions for human cells to develop of the coronavirus spike protein.

This trains the human immune system to be prepared in the event that it then encounters the real coronavirus. The Sputnik V vaccine uses two different adenovirus vectors to accomplish this task: adenovirus type 26 (Ad26) for the first shot and adenovirus type 5 (Ad5) for the second shot.

According to a slideshow uploaded online, scientists from Anvisa, Brazil’s regulatory agency, said they tested samples of the booster shot and found it to be “replication-competent” – meaning the adenovirus can continue to multiply in the body.

They added that this was likely due to a manufacturing problem called “recombination,” where the modified adenovirus had regained the genes it needed to replicate while grown in a laboratory in engineered human cells.

The Brazilian regulators did not rate the first shot.

On Monday, they denied a request by several states in the northeastern part of the country to purchase more than 30 million doses of the Sputnik V vaccine. The federal government has ordered 10 million more cans from Russia.

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The timing of the import ban couldn’t be worse for Brazil, which is battling a devastating wave of infections stemming from both government mistreatment of the crisis and a highly infectious variant of the virus first discovered in the country.

“Potentially Serious” Side Effects

Rasmussen, a scientist with the Canadian Organization for Vaccines and Infectious Diseases, described the problem as a quality control problem rather than a problem inherent in long-standing adenovirus vector vaccine technology that is also used in both countries AstraZeneca and Johnson & Johnson Covid19 vaccinations.

If batches used in the real world are spoiled then “it probably won’t be a big deal for most people, as adenoviruses are generally not considered to be really major human pathogens,” she said.

“But people with compromised immune systems … may experience a higher rate of side effects, including potentially more serious ones.”

The bigger problem, she added, was the unfortunate impact on vaccine confidence a study in The Lancet Journal had was safe and more than 90% effective. However, there have long been doubts about the Russian vaccine since it was first approved for use in Russia – months before the results of end-stage clinical trials were even published.

If people aren’t sure if the vaccine they’re getting is exactly the same one that studies have looked at, then “I can imagine some people have reservations about getting this vaccine in the first place,” Rasmussen said.

Problems with Sputnik V.

Another unknown is whether the manufacturing problem that caused the adenovirus vector to replicate also turns off the DNA code for the spike protein – making the shot ineffective as a coronavirus vaccine.

Denis Logunov, deputy director of the Gamaleya Institute, replied by saying, “the statements I read in the press have nothing to do with reality,” insisting that the adenovirus vector used in Sputnik V did not replicate.

However, it’s not the first time you’ve encountered such a problem.

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Earlier this month, Slovakia also said it had concerns about the composition of the Sputnik V vaccines it imported, as it did not match the samples used in clinical trials.

In a blog post for Science Magazine, American chemist Derek Lowe wrote, “This kind of thing calls into question the whole manufacturing and quality control process, and I can see why Brazilian regulators are concerned.”

He added that the reaction from the makers of Sputnik V was not appropriate.

“Step up and act like responsible drug developers: approach problems directly and transparently and work to find a solution,” said Lowe.

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