Nature: intravenous injection can significantly improve the efficacy of tuberculosis vaccine

January 4, 2020 / Bio Valley BIOON / - -- globally, although the vast majority of people have been vaccinated, the number of people who die of tuberculosis still exceeds that of any other infectious disease BCG (Bacillus Calmette Gu é RIN) is the only commercially available human tuberculosis vaccine (TB vaccine), which is a live vaccine made of attenuated bovine tuberculosis suspension BCG vaccine has a history of more than 100 years and is one of the most widely used vaccines in the world However, its efficacy varies greatly In a new study, researchers from the National Institute of allergy and infectious diseases (NIAID) and the University of Pittsburgh School of medicine took monkeys as research objects and found that intravenous TB vaccine can highly protect monkeys from TB infection In contrast, as the current standard delivery way, TB vaccine is directly injected Radiation into the skin provides little protection This finding suggests that changing the way TB vaccine is delivered may significantly enhance its protection The relevant research results were published in the nature Journal on January 2, 2020, with the title of "prevention of tuberculosis in macaques after indoor BCG immunization" Picture from nature, 2020, DOI: 10.1038/s41586-019-1817-8 "The effect is very significant," said Joanne Flynn, Ph.D., senior author of the paper and professor of Microbiology and molecular genetics at the center for vaccine research, University of Pittsburgh School of medicine Compared to the standard skin to TB vaccinated monkeys, we found a 100000 fold reduction in bacterial burden in the lungs of the intravenous to TB vaccinated monkeys, and in nine of the 10 intravenous monkeys, there was no inflammation in the lungs " The idea of intravenously administered TB vaccine came from an early experiment by Robert Seder, Ph.D., Ph.D., of the vaccine research center of the National Institute of allergy and infectious diseases Seder found that intravenous malaria vaccine was more effective in both animals and humans To test whether the vaccine is effective against TB, Flynn and colleagues tested several routes and doses of TB vaccine (BCG vaccine) They divided a group of monkeys into 6 groups: the unvaccinated monkeys, the monkeys who sent the standard vaccine dose through the skin, the injection of more monkeys to the larger doses of the vaccine through the skin, the monkeys sent through the skin injection and spray, and the monkeys who were given a larger dose of vaccine by intravenous injection Six months later, they exposed the monkeys to TB and monitored their signs of infection All monkeys given standard doses of the vaccine had persistent lung inflammation, and the average number of TB bacteria in their lungs was only less than that of unvaccinated monkeys Monkeys who received larger doses of vaccine through skin injection and monkeys injected with skin injection and spray provided similar moderate protection against TB On the other hand, the intravenous vaccine provided almost complete protection; the lungs of these monkeys receiving the intravenous vaccine were almost free of TB bacteria, and only one monkey in this group developed lung inflammation "The reason why intravenous delivery is so effective is that the TB vaccine quickly reaches the lungs, lymph nodes and spleen through the blood and prepares T cells for an immune attack before they are killed," Flynn explained Flynn and his team found BCG and activated T cells in the lungs of all monkeys who were given the vaccine intravenously In other monkeys, BCG was not detected in lung tissue, and T cell response was relatively weak Next, they plan to test whether lower doses of intravenous BCG provide the same level of protection and do not produce side effects such as temporary lung inflammation But before using this method in the human body, scientists need to know that it is not only safe but also practical Intravenous vaccination requires more skills and has a higher risk of infection "We have a long way to go to realize the transformational potential of this research, but we want to test it in humans," Flynn said (BIOON Com) reference: 1 Patricia a Darrah et al Prevention of tuberculosis in macaques after invasive BCG immunization Nature, 2020, DOI: 10.1038/s41586-019-1817-8 2 Delivering TB safely internally draughtly improved potency, study shows https://medicalxpress.com/news/2020-01-tb-vaccine-intravenously-potency.html