The SA Health Products Regulatory Authority said there have been concerns raised about the safety of Ad5-vectored vaccines in populations at risk for HIV infection.
THE SOUTH African Health Products Regulatory Authority (Sahpra) has made the decision to not approve the Covid-19 Sputnik V vaccine because of concerns about its safety in populations at risk for HIV infection.
On Monday, Sahpra said a rolling review of the Sputnik V vaccine would remain open for submission of relevant safety data in support of the application.
“The Section 21 application for Sputnik V by Lamar international Pty (Ltd) will not be approved at this time. Sahpra is concerned that use of the Sputnik V vaccine in South Africa, a setting of a high HIV prevalence and incidence, may increase the risk of vaccinated males acquiring HIV.”
The Sputnik V vaccine was developed by the Gamaleya Research Institute of Epidemiology and Microbiology in the Russian Federation and has been in Sahpra’s rolling review process since the first application was submitted on February 23 this year.
Sputnik V is a viral vector vaccine that uses an engineered adenovirus — a family of viruses that generally cause mild illness — and trains the body’s immune system to recognise Sars-CoV-2 and fight it off.
It is similar to the Johnson & Johnson and AstraZeneca vaccines, however, instead of one engineered adenovirus, Sputnik V combines two separate adenovirus-vectored constructs, Adenovirus Type 26 (Ad26) and Adenovirus Type 5 (Ad5).
Sahpra said there have been concerns 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,” said the health regulator.
During the assessment of the application for approval of the Sputnik V vaccine, Sahpra reviewed the outcomes of two clinical trials in particular.
“In both the Step clinical and Phambili trials, administration of an Ad5-vectored vaccine was associated with enhanced susceptibility/acquisition of HIV in men.”
“Sahpra, therefore, requested the applicant to provide data demonstrating the safety of the Sputnik V vaccine in settings of high HIV prevalence and incidence. The applicant was not able to adequately address Sahpra’s request.”
The World Health Organization (WHO) has not listed the Sputnik V vaccine for emergency use, indicating that the process is “on hold, awaiting completion of rolling submission”.