The stakes escalated yesterday when the Twitter account officially associated with the vaccine said “Sputnik V is undertaking a legal defamation proceeding” against Brazil’s regulators.
In an online press conference several hours later, the Brazilian Health Regulatory Agency (Anvisa) defended its decision, maintaining that documentation from some of the Russian facilities making Sputnik V shows that one of its two doses contains adenoviruses capable of replication, a potential danger to vaccine recipients. The vaccine uses two different adenoviruses, which cause a severe cold, to deliver the gene for the spike protein of SARS-CoV-2, the virus that causes COVID-19. Both are supposed to be stripped of a key gene that allows them to replicate.
The Monday announcement left many scientists and media outlets believing Anvisa had directly tested Sputnik V for replicating adenoviruses, which would be unusual for a regulatory agency. But Anvisa has since clarified—it had not and was relying on information provided by the Gamaleya National Center of Epidemiology and Microbiology, the Moscow-based developer of the vaccine.
“The data we evaluated shows the presence of replicating virus,” Gustavo Mendes, general manager of medicines and biological products at Anvisa, said at the press conference. Anvisa would not accept the vaccine, he said, without further studies to indicate it is safe.
The Anvisa review of Sputnik V was triggered because the Brazilian governors needed the agency’s sign-off to import the vaccine. Anvisa said that although the standard worldwide has been zero tolerance for the presence of replicating adenovirus in the vaccine, Gamaleya established an acceptable limit of 5000 replication-capable virus particles per vaccine dose.
During yesterday’s press conference, Mendes also showed video of parts of an online meeting in March between officials from Anvisa and the vaccine’s developer. In one of the clips, Anvisa officials ask Gamaleya representatives why they had not changed their production methods once they “had detected the RCA occurrence in your production.” The Gamaleya representatives responded that they were aware of the risk, but that changing the process “would take too much time.”