The South African Health Products Regulatory Authority (Sahpra) has not approved the Russian-developed Sputnik V Covid-19 vaccine for use in South Africa, citing safety concerns due to the country’s HIV rate.
In a statement on Monday (18 October), the regulator noted that the Sputnik V vaccine combines two separate adenovirus-vectored constructs, one relying on the Adenovirus Type 26 (Ad26) and the other on Adenovirus Type 5 (Ad5), as the delivery vehicles for the antigen.
“Concerns have been raised about the safety of Ad5-vectored vaccines in populations at risk for HIV infection. One of the challenges faced by such vaccines is the presence of pre-existing Ad-specific neutralising antibodies (NAbs) in the general population,” it said.
The regulator cited two HIV trials conducted in South Africa which showed that administration of an Ad5-vectored vaccine was associated with enhanced susceptibility/acquisition of HIV in men.
Sahpra also referred to medical arguments published in The Lancet, which showed similar trends in a non-human primate study. In addition, Sahpra held a consultation meeting with expert committees, including leading local and international scientific community members on this matter.
The regulator has also asked the Sputnik V vaccine maker to provide data demonstrating the safety of the Sputnik V vaccine in settings of high HIV prevalence and incidence. However, the applicant was not able to adequately address this request, it said.
“Sahpra is concerned that use of the Sputnik V vaccine in South African, a setting of a high HIV prevalence and incidence, may increase the risk of vaccinated males acquiring HIV.
“The rolling review of the Sputnik V vaccine will, however, remain open for submission of relevant safety data in support of the application,” it said.
In response to Sahpra’s statement, Russia’s Gamaleya Center of Epidemiology and Microbiology said that the concerns around the Sputnik V vaccine and HIV are unfounded.
“Sahpra has confirmed that the rolling review of Sputnik V continues. All the required information confirming that possible concerns about the safety of Ad5-vectored vaccines in populations at risk for HIV infection are completely unfounded will be submitted to the South African regulator,” it said.
There is no scientific or clinical evidence confirming the association of wild type adenoviruses or replicative defective adenovirus vectors with increased risk of HIV infection, it said.
“Speculation regarding the association between adenovirus type-5 vectored vaccines and HIV transmission has been based on small-scale studies among volunteers with highly probable risky behaviour.
In contrast, a meta-analysis of six clinical studies and their long-term follow-up in 7,092 participants showed that, after rigorous statistical analysis of pooled individual participant-level data, there was no statistically significant increase of HIV-1 infection among adenovirus type-5 vectored vacсine recipients when all study participants and follow-up time were considered.”
The human adenovirus 5 is already used in other popular vaccines, including Cansino, which is widely applied in China, including during vaccination of the Chinese military, and approved around the world, the center added.
“The efficacy of the human adenoviral vector platform has been widely and internationally proven in non-Covid-19 vaccines. More than 250 clinical trials and 75 international publications confirm the safety of vaccines and medicines that are based on human adenovirus vectors.”
This article has been updated with comments from the Russian Direct Investment Fund and the Gamaleya Center of Epidemiology and Microbiology.