VPM1002 Vaccine Falls Short
VPM1002 vaccine not more effective than BCG vaccine in preventing tuberculosis infection in newborns
The VPM1002 vaccine, an investigational tuberculosis vaccine, was found to be not more effective at preventing tuberculosis infection compared with the standard BCG vaccine in newborns, according to a phase III trial. Among nearly 6,900 newborns in sub-Saharan Africa, QuantiFERON-TB Gold Plus conversion occurred in 5.3% of those who received the VPM1002 vaccine compared with 4.3% of those who received the BCG vaccine.
Trial Details
The trial, which was terminated early due to fewer QFT conversions than predicted, randomized 6,940 newborns to vaccination with either VPM1002 or BCG. The primary efficacy endpoint was the occurrence of QFT conversion, indicating M. tuberculosis infection or exposure. Secondary endpoints included protective efficacy against microbiologically confirmed and unconfirmed TB disease.
Efficacy Results
The results showed that the VPM1002 vaccine was not more effective at preventing tuberculosis infection compared with the BCG vaccine. For events meeting the first-case definition for QFT conversion in the VPM1002 group versus the BCG group, the HR was 1.23. Noninferiority required the upper bound of the confidence interval to be less than 1.25. The trial also delivered uncertainty about VPM1002's relative efficacy at preventing TB disease.
Comparison of Vaccine Efficacy
The following table compares the efficacy of the VPM1002 and BCG vaccines:
| Vaccine | QFT Conversion Rate | Microbiologically Confirmed TB Disease Rate |
|---|---|---|
| VPM1002 | 5.3% | 3.2% |
| BCG | 4.3% | 1.7% |
The results suggest that the VPM1002 vaccine may not be a suitable replacement for the BCG vaccine, and that further research is needed to develop a more effective tuberculosis vaccine. As noted by Helen McShane, PhD, of the University of Oxford, finding a more effective TB vaccine than BCG is an urgent global health priority, and better TB trial designs and endpoints are crucial to achieving that goal. The trial's findings highlight the methodological challenges of using QFT-based infection endpoints in infant vaccine trials and the importance of accounting for differential tuberculosis exposure in the design and analysis of future prevention of infection trials. According to Sina Brückner, PhD, and colleagues, tuberculosis disease is a more appropriate endpoint in infant vaccine trials. The safety profiles of the two vaccines were similar, with at least one solicited adverse event in 75% of those in the VPM1002 group versus 67% of those in the BCG group. Rates of serious adverse events were also similar, at 10.7% vs 9.4%, respectively. The study was published in Lancet Infectious Diseases, as reported by MedPage Today.
