Human studies have demonstrated the safety of two new chlamydia vaccines, one of the most common sexually transmitted diseases. Both have successfully completed the first phase of clinical trials, demonstrating their immunogenicity and lack of side effects, the magazine said. Lancet infectious diseases,
bacteria Chlamidia trachomatis are transmitted from person to person through sexual contact and provoke diseases of the genitourinary system. In many cases, chlamydia is almost asymptomatic, but can cause serious complications and is dangerous during pregnancy. The "quiet" lifestyle of bacteria allows them to go unnoticed for a long time in the body, so many people begin treatment with a long delay. This has made chlamydia one of the most common sexually transmitted diseases – according to WHO estimates, in 2016 alone, 127 million people became ill worldwide. Chlamydia is treated with antibiotics, but for the above reasons it slows down the overall spread of the infection, so developing preventative methods to protect against the disease, including vaccines, is very important.
Sonya Abraham and her colleagues recently successfully completed the first phase of clinical vaccine trials. The study was conducted at Hammersmith Hospital in London for 35 people: two groups of 15 healthy women tested two vaccine variants and another five were in the control group. They all received three injections within four months, then two more doses in the form of a nasal spray, and neither the subjects nor the doctors knew who belonged to which group. The study did not reveal any serious side effects and the problems identified, such as pain from injections, were distributed mainly between the three groups. It is worth noting that this is the first phase of clinical trials and there are few people – some effects may appear in the future.
Both vaccines showed their efficacy and gave (unlike placebo) an immune response, but one of them proved more promising for further studies. Both options are based on the bacterial membrane protein. C. trachomatis, but various supplements have been used as enhancers of the immune response. CTH522: AH is the standard adjuvant for many aluminum hydroxide vaccines, and CTH522: CAF01 is CAF01, a relatively new addition to the cationic liposome. Antibodies to the second vaccine were previously found in the blood, there were more of them, and overall the immune response was more potent. These advantages increase her chances of moving to the next testing phase, which the authors of the article plan to conduct on a larger sample.
Researchers recently reported successful trials of a vaccine against another common malaria disease. Experiments involving 2,100 patients have shown its absolute efficacy.