Brazil’s decision to halt Sputnik V vaccine import gains support in scientific world

RIO DE JANEIRO, BRAZIL – U.S. scientists have endorsed Brazil’s health regulator’s decision to stop the imports of Russian Sputnik V vaccine against Covid-19 after determining that the batches shipped carried a live version of a common virus that causes colds and even gastroenteritis.

Renowned Canadian virologist Angela Rasmussen told several media outlets and posted on her Twitter profile Thursday that the finding “raises questions about the integrity of the manufacturing processes” and could be a safety issue for people with weaker immune systems, should findings show that the issue is widespread.

The Brazilian Health Regulatory Agency (ANVISA) decision and Rasmussen’s opinion, replicated on social networks, were followed by voices from the scientific world. “This kind of thing challenges the whole manufacturing and quality control process,” said chemist Derek Lowe in a blog post in Science Magazine.

The Kremlin rushed to try to mitigate the reports that began in Brazil and spread worldwide. Russia’s Gamaleya Institute, which developed the vaccine, disputed the reports.

The problem is focused on an “adenovirus vector,” a pathogen that typically causes a mild respiratory disease but which in vaccines is genetically modified to prevent its replication. In addition, this pathogen is modified to carry the DNA instructions for human cells to develop the coronavirus spike protein, which causes the disease.

This, in turn, trains the human system to be prepared in case it later meets the actual coronavirus.

The Sputnik V vaccine, a two-dose immunizer, uses 2 different adenovirus vectors to perform this task: adenovirus type 26 (Ad26) for the first injection, and adenovirus type 5 (Ad5) for the second.

ANVISA scientists said they analyzed samples from the second dose and found that it was “capable of replication,” meaning that once inside the body, the adenovirus could continue to multiply.

In a presentation released online, they added that this had likely occurred due to a manufacturing issue called “recombination,” in which the modified adenovirus had recovered the genes it needed to replicate while being grown inside modified human cells in a laboratory.

ANVISA scientists did not evaluate the first shot. However, on Monday they denied a request from several northeastern Brazilian states to purchase over 30 million doses of the Sputnik V vaccine. The federal government has ordered an additional 10 million.

The news shocked several parts of the world and raised concern among the scientific community. U.S. news network CBS, French news agency AFP and other media outlets sounded the alarm bells as to what was happening with the Russian development. Italian newspaper Corriere Della Sera also reported the information and consulted with experts.

“Sputnik’s problem seems to be serious. The vaccine must consist of a virus that cannot replicate, while all the samples tested in Brazil contained viruses capable of replication. The unanimous rejection is not surprising,” said renowned virologist Roberto Burioni from Milan.

Source: Infobae

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