Scientists support the Brazilian drug regulator's decision to block the import of the Russian COVID vaccine Sputnik V due to seeing it carried a live version of a common cold-causing virus.

Top virologist Angela Rasmussen said that it raises concerns on the integrity of the manufacturing processes, according to a CBS News report.

Rasmussen added that it could be a safety issue for people with weaker immune systems if it were widespread.

Brazil's health authority announced earlier this week that it would not recommend importing the Russian COVID vaccine despite the urgent need for vaccines in the country.

All five of Anvisa's directors voted against the importing of the vaccine, according to The New York Times report.

Gustavo Mendes Lima Santos, Anvisa's manager of medicine and biological products, said that Sputnik V's efficacy was "uncertain.

Santos added that crucial questions had been unanswered, including the adverse side effects of the vaccine.

READ MORE: Mexico Unsure if Seized Russian Sputnik V Vaccines Are Real or Fake

Brazil on Sputnik V

The Kremlin spokesman, Dmitri S. Peskov, said that the Russian government would try to win over the Brazilian regulators' minds about the vaccine's safety.

Peskov said that contact will continue.

"If data is missing, it will be provided. There should be no doubt in this," Peskov was quoted in a report.

Brazilian states had contracts to buy almost 30 million doses of Sputnik V, putting huge pressure on Anvisa over their decision.

An Anvisa director, Alex Machado, said that the days of yes to the vaccine and treatment available are celebrated. However, he noted that there will also be days of no.

One of the states that procured Sputnik V's doses was Ceara.

Gov. Camilo Santana said he respected Anvisa's decision but argued that the vaccine is being used in other countries as well.

Santana said he will keep fighting for this authorization in a safe manner while following the rules.

Meanwhile, Anvisa's director, Antonio Barra Torres, said that the agency had been accused of lying, acting unethically, and spreading fake news.

Torres said they refute the said allegations, according to a Channel News Asia report.

Torres cleared that they are not closing the door on using the vaccine, adding that the data presented can be revised, corrected, and presented again.

Russia's COVID vaccine

Slovakia had concerns over the composition of Sputnik V vaccines earlier this month.

It said that they did not match the samples that were used in clinical studies, according to an AFP News report.

American chemist Derek Lowe commented on the matter, saying that it puts a question over the entire manufacturing and quality control process.

He added that he can see why the Brazilian regulators are concerned.

Lowe also said that Sputnik V's makers should address the issues directly with transparency and work to find a solution.

Sputnik V vaccine uses different adenovirus vectors to do its work on protecting individuals against the COVID pandemic.

It is also given in two shots like other vaccine candidates, except Johnson & Johnson.

Gamaleya Institute had argued that the vaccine contained no replicating virus.

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