Professor Shabir Madhi gives update on SA’s first COVID-19 vaccine trials

South Africa has been at the forefront of COVID-19 vaccine trials, with the first trials beginning almost three weeks ago. Professor Shabir Madhi, a leading expert in vaccineology at the University of Witwatersrand, provided an update on the progress of the trials and discussed emerging evidence on the airborne transmission of the virus. The rapid rate at which the virus is currently spreading in the areas where the study is being conducted has posed unexpected challenges for the trial. Professor Madhi highlighted the high percentage of asymptomatic individuals who are unknowingly infected with the virus, making it challenging to accurately screen participants for the trial. The initial estimates of the number of infected individuals proved to be a vast underestimate, prompting the need to refine the inclusion criteria for the study. As a result, screening for previous or current infections has become a crucial step in enrolling participants to ensure the study's scientific integrity. Despite these challenges, Professor Madhi remains optimistic about the progress of the trial and the potential effectiveness of the vaccine against COVID-19. In addition to the vaccine trials, the discussion also touched on the evolving understanding of the transmission of the virus. Recent studies have suggested the possibility of airborne transmission, where the virus can linger in the air for an extended period, especially in poorly ventilated areas. While this hypothesis has not been officially confirmed by the World Health Organization (WHO), the growing body of evidence, including observations from South Africa, points towards the likelihood of airborne transmission playing a significant role in the spread of the virus. Professor Madhi emphasized the importance of considering multiple modes of transmission and the varying impact of each mode in different settings. Factors such as ventilation and overcrowding can influence the likelihood of airborne transmission, highlighting the need for tailored prevention strategies based on specific environmental conditions. The evolving understanding of COVID-19 transmission underscores the complexity of combating the virus and the importance of continued research to inform effective public health measures. As South Africa continues to navigate the challenges posed by the pandemic, the ongoing vaccine trials and research efforts are critical in the global fight against COVID-19.