JOHANNESBURG (Reuters) - South Africa's drugs regulator said on Monday that it was not approving an emergency use application for Russia's Sputnik V COVID-19 shot for now, citing concerns about its safety for people at risk of HIV.
South Africa has one of the world's highest HIV burdens, and some studies have suggested that administration of vaccines using the Adenovirus Type 5 (Ad5) vector - which Sputnik V does - can lead to higher susceptibility to HIV in men.
Viral vector vaccines like Sputnik V use modified viruses as vehicles, or vectors, to carry genetic information that helps the body build immunity against future infections.
SAHPRA, the regulator, said it had asked for data demonstrating Sputnik V was safe in settings with high HIV prevalence, but that it had not received enough to establish this.
"SAHPRA resolved that the ... (emergency) application for Sputnik V ... not be approved at this time. SAHPRA is concerned that use of the Sputnik V vaccine in ... a setting of a high HIV prevalence and incidence may increase the risk of vaccinated males acquiring HIV," the statement read.
The Gamaleya Institute, which developed Sputnik V, said: "Concerns about the safety of Ad5-vectored vaccines in populations at risk for HIV infection are completely unfounded," adding that SAHPRA would get all the information it needed.
More than 250 clinical trials and 75 international publications confirm the safety of vaccines and medicines based on human adenovirus vectors, the institute added.
SAHPRA said it had consulted with local and international scientific experts to reach its decision, and that relevant safety data could still be submitted as its "rolling review" of the vaccine would remain open.
South Africa, which has bilateral deals for the two-dose Pfizer and one-shot Johnson & Johnson vaccines, has now administered more than 20 million doses. Around 14 million people have had at least one dose of vaccine, representing 35% of its adult population.
(Reporting by Alexander Winning in Johannesburg and Polina Nikolskaya in Moscow; Editing by Tim Cocks and Giles Elgood)