Beyond Antibiotics Towards Preventative Vaccines
Vaccines have been shown to be successful at drastically curbing infection rates they are responsible for the eradication of for example, widespread vaccination of girls aged 12 and 13 against human papillomavirus was recently shown by a Canadian study to significantly reduce the prevalence of genital and cervical cancer-causing strains of the virus.
The success of the HPV vaccines has shown us how effective vaccination can be against a sexually transmitted infection encouraged researchers from Statens Serum Institut , Denmark, and Imperial College London to develop a preventative vaccine for chlamydia, SSI Department of Infectious Disease Immunology director Frank Follman explains.
Imperial College London Department of Infectious Disease Mucosal Infection and Immunity unit head Professor Robin Shattock noted: It is very treatable if identified, but as many people dont have symptoms it can be missed.
One of the problems we see with current efforts to treat chlamydia is that despite a very big screening, test and treat programme, people get repeatedly re-infected. If you could introduce a protective vaccine, you could break that cycle.
The Hepatitis A Vaccine
Hepatitis A has been making headlines quite a bit lately, because our country is seeing the worst outbreak in years,particularly affecting the homeless community in San Diego. Hepatitis A is a type of liver disease. You’ve probably heard that it’s most commonly contracted due to dirty food or water . While this is true, you can also contract it from certain sexual activities.
There is good news, though: hepatitis A is totally preventable when you get the vaccine, which consists of two shots administered six months apart.
A Chlamydia Vaccine Shows Signs Of Success In An Early Trial
Scientists have taken a step towards a vaccine for chlamydia following a successful early trial.
A vaccine developed by a British and Danish team was shown to be safe and effective during a randomized controlled trial involving 35 women, according to a study published in medical journal The Lancet Infectious Diseases.
Chlamydia is the most common bacterial sexually transmitted infection in the world. There are 131 million new cases every year, according to Imperial College London, with as many as three-quarters showing no symptoms. However it can cause infertility if left untreated.
The researchers, from Imperial College London, UK, and the Statens Serum Institut , Denmark, acknowledge that the development of the vaccine has a long way to go. It had however produced the immune response they had hoped for, and none of the women developed any serious side effects.
The most important result is that we have seen protective antibodies against chlamydia in the genital tracts, said study author Frank Follmann of SSI in a statement.
Our initial trials show them preventing the chlamydia bacteria from penetrating the cells of the body. This means that we have come a lot closer to a vaccine against chlamydia.
This is the first clinical trial for a vaccine for genital chlamydia and represents the latest development in 15 years of research, according to an SSI statement.
However there remains a lot of work to be done, according to study author Robin Shattock of Imperial College.
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Promising Immune Response From Chlamydia Vaccine
The two versions of the vaccines were well tolerated and immunogenic no participants of the placebo group achieved an immune response.
Shattock commented: The findings are encouraging as they show the vaccine is safe and produces the type of immune response that could potentially protect against chlamydia. Folmann explains the reason for its success was the vaccines combination of neutralizing antibodies and T cells.
The most important result is that we have seen protective antibodies against Chlamydia in the genital tracts. Local immunity in the genital tract is important to stop the infection as quickly as possible Follmann added in a statement. This will help to generate a long term immune response against the bacterial condition.
Due to the vaccines success, the researchers are planning to move into further clinical trials to find out whether it is truly protective or not, Shattock explained. It is likely that the more effective of the two, the CTH522 vaccine adjuvanted with CAF01 liposomes, will become the primary focus of future trials.
In the long term, the researchers are considering combining their chlamydia vaccine with the successful HPV vaccine in the same target population, to further prevent severe consequences these STIs can have on womens health, notes Folmann.
Videoone In Four Teen Girls In Us Has Std
Infectious disease experts say the experimental vaccine is promising because it seems to target the bacterial infection where it hides: inside the cells.
“A lot of the current vaccines that are used in people induce mostly an antibody response,” said Dr. Toni Darville, chief of pediatric infectious disease at the University of North Carolina Children’s Research Institute, who was not involved with the study. “The problem with chlamydia is that it lives inside cells and replicates inside cells. You really need a T-cell response to combat this infection.”
Darville also wrote a commentary accompanying the newly published research.
There were more than 1.7 million cases of chlamydia in the United States in 2017 alone, according to the Centers for Disease Control and Prevention. Most of the 200,000 cases diagnosed each year occur in young people.
“Up to 10 percent of sexually active teenagers and young adults are infected with chlamydia,” Darville said.
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The Host Response To Infection
Since widespread antibiotic therapy was introduced serum anti-Ct antibodies have declined in parallel with increased Ct prevalence. Whilst clearing infection, antibiotics may alter the development of immunity. It remains controversial whether pathology is caused directly by infection or by the immune response. There is evidence that women who make a pro-inflammatory, interferon- dominated cytokine response have less re-infection and infertility than those who make IL-10 and IL-4 dominated Th2 responses. As IFN- induces a persistent non-infectious state in Ct in vitro it remains unclear whether a Th1 response completely clears infection in vivo. Th1 dependent IgG2 antibodies to Ct antigens are higher in women with cervicitis and PID indicating that Th1 responses may be associated with inflammatory pathology.
Is A Chlamydia Vaccine On The Horizon
MONDAY, Aug. 12, 2019 — A vaccine against the sexually transmitted disease chlamydia appears safe and potentially effective, an early trial suggests.
The phase 1 study included 35 healthy women. Those who were given injections of two possible vaccines developed antibodies to the chlamydia bacteria, but a lot more testing is needed before the vaccine would be ready for the public, the researchers added.
“An effective vaccine against chlamydia would have enormous public health and economic impact,” said lead researcher Frank Follmann. He is director of infectious disease immunology at the Center for Vaccine Research at Statens Serum Institute in Copenhagen, Denmark.
“This is a promising first step on the road to develop a vaccine,” he said. “The success of the HPV vaccine has shown us how effective vaccination can be against a sexually transmitted infection. We hope to do the same with chlamydia and, in the long term, combine the two vaccines.”
The results of this study are encouraging, and larger trials are planned, Follmann said. “The goal is to vaccinate girls before they become sexually active,” he explained.
One expert said the findings show promise.
In the vaccine trial, the women were randomly assigned to one of two different vaccines or a placebo.
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Stds That Don’t Have A Vaccine
HPV, hepatitis A, and hepatitis B are currently the only three STDs that can be prevented by vaccines. Other sexually transmitted diseases, including gonorrhea, chlamydia, and syphilis, do not yet have a vaccine. This could be because there is already wide availability of treatments for infected people , so vaccines haven’t been as much of a priority as they might be for other diseases not easily treated.
However, humans are becoming so resistant to certain diseases, like gonorrhea, that vaccines might be available in the future. There are already other STD vaccines that are in development, too. For instance, science has been experimenting with a genital herpes vaccine since the 1930s. However, none of the vaccinations developed have yet been found to work well enough to be approved and licensed.
Researchers have also played with the idea of an HIV vaccine. Several vaccines have been tested in clinical trials, but none have been approved yet. Accomplishing this specific vaccine is incredibly difficult for several reasons. For starters, HIV can mutate very quickly, making it harder to pinpoint and protect against long-term. Secondly, HIV damages the immune system, but the vaccine must trigger the immune system to work. While preventative HIV vaccines have been developed to protect people from it, none have been approved by the FDA, and you need to be enrolled in a clinical trial to receive one.
Medical Contraindications/exemptions For Covid
Earlier this month, we reviewed contraindications for influenza vaccination. As the nation discusses mandatory COVID-19 vaccination, we primary care clinicians are being asked to certify contraindications and precautions for these vaccines.
The only true contraindications for any of the COVID-19 vaccines are:
- Severe allergic reaction after a previous dose or to a component of the COVID-19 vaccine.
- Immediate allergic reaction of any severity after a previous dose or known allergy to a component of a COVID-19 vaccine.
Patients with these reactions should not get the same type of COVID-19 vaccine . There is a list of chemical components in each vaccine at the link below .
There are also precautions for COVID-19 vaccination. If a precaution exists, a patient may get the vaccine, but preferably in a prepared medical setting with supplies and personnel capable of recognizing and addressing anaphylaxis . These patients should be observed for 30 minutes rather than the usual 15.
- Any immediate allergic reaction to other vaccines or injectable therapies.
- A history of a contraindication to mRNA vaccines is a precaution to Janssen vaccine and vice versa.
It is important to discuss these precautions with the patient to reach a shared decision – discussing risk for acquiring COVID-19, risk of severe COVID-19 illness, and unknown risk of anaphylaxis in people with such reactions to other vaccinations.
The following are considered NEITHER contraindications NOR precautions:
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Chlamydia Trachomatis Vaccine Research Through The Years
1Department of Molecular Biotechnology, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Ghent, Belgium
Chlamydia trachomatis is a Gram-negative obligate intracellular bacterium. It is the leading cause of bacterial sexual transmitted infections . World Health Organization figures estimated that over 90 million new cases of genital C. trachomatis infections occur worldwide each year. A vaccination program is considered to be the best approach to reduce the prevalence of C. trachomatis infections, as it would be much cheaper and have a greater impact on controlling C. trachomatis infections worldwide rather than a screening program or treating infections with antibiotics. Currently, there are no vaccines available which effectively protect against a C. trachomatis genital infection despite the many efforts that have been made throughout the years. In this paper, the many attempts to develop a protective vaccine against a genital C. trachomatis infection will be reviewed.
2. Chlamydia muridarum versus C. trachomatis Mouse Models
As there are considerable differences between the C. muridarum and the C. trachomatis murine model, it is difficult to make direct comparisons. In order to understand the pathogenesis of human chlamydial infections completely, it is absolutely necessary to thoroughly investigate chlamydial infection in its natural human host .
3. Protective Immune Responses to C. trachomatis
Which Stds Have Vaccines
Some STDs, such as such as gonorrhea, Chlamydia, and syphilis, are caused by bacteria. They are usually effectively treated with antibiotics, although many patients do not know that they are infective and can spread the disease to other partners. The availability of treatments means that the need for vaccines against these diseases is not a top priority, although the increased resistance of gonorrhea to antibiotics may lead to a shift in priorities.
Viral STDs are often highly persistent despite current therapeutic options or have no acceptable treatment available. Therefore, vaccines for certain viral STDs are in use, and others are in development.
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Difficult To Attack / Chlamydias Weak Point
The successful trial is the preliminary culmination of 15 years of research on developing an effective Chlamydia vaccine. The project started in 2004 and was in part funded by EUs 7th framework programme and Innovation fund Denmark.
The challenge has been to find the weak point of the Chlamydia bacteria and also to find the most effective way of vaccinating.
A few years ago, researchers solved the first part of the challenge. They discovered that the weak point of the Chlamydia bacteria was a special protein in the bacteria. Since then they have experimented on finding a new and more effective way of vaccinating to target this exact protein.
Full Speed Ahead On The Development Of The Vaccine
The question now is if the vaccine will protect against Chlamydia when women are infected in the real world.
Research shows that the combination of antibodies and T cells does protect against Chlamydia, but, of course, we have to test the vaccine in larger and more long-termed clinical trials to see if it protects against infection. Given the results at hand, we have accelerated our further clinical trials, says Frank Follmann.
Professor Peter L. Andersen, Head of SSIs Center for Vaccine Research, continues:
The HPV vaccine has shown us how effective vaccination can be against a sexually transmitted infection. We hope to do the same with Chlamydia and, in the long term, combine the two vaccines.
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First Widely Protective Vaccine Against Chlamydia
- McMaster University
- The first steps towards developing a vaccine against an insidious sexual transmitted infection have been accomplished.
The first steps towards developing a vaccine against an insidious sexual transmitted infection have been accomplished by researchers at McMaster University.
Researchers at the Michael G. DeGroote Institute for Infectious Disease Research at McMaster have developed the first widely protective vaccine against chlamydia, a common STI that is mostly asymptomatic but impacts 113 million people around the world each year and can result in infertility.
In a study, recently published in the journal Vaccine, the researchers show that a novel chlamydial antigen known as BD584 is a potential vaccine candidate for the most common species of chlamydia known as Chlamydia trachomatis.
As most C. trachomatis infections are asymptomatic, chlamydia can often go untreated and lead to upper genital tract infections, pelvic inflammatory disease, and infertility. This is why the promise of a vaccine would be extremely beneficial, says David Bulir, co-author of the study.
“Vaccine development efforts in the past three decades have been unproductive and there is no vaccine approved for use in humans,” said Bulir, who just finished his PhD in medical sciences at McMaster.
Trachoma is an eye infection caused by chlamydia and is the leading cause of preventable blindness affecting millions of people in many resource-poor regions of the world.
Vaccine Results No Challenge
Of the 44 studies that did not include a post-vaccine Chlamydia challenge, 18 studies were performed in mice, 11 studies in koalas, four studies in sheep, and one or two in birds, pigs, humans, non-human primates and rabbits. In some of these studies, such as with the human and koala subjects, ethical restrictions most likely prevented the study design from including a challenge component . This type of restriction will continue to be a limitation for vaccine design in some hosts and helps explain why the Chlamydia mouse model remains a popular research tool. The results of these no challenge trials varied and were dependant on the in vitro tests performed on collected samples, predominately focused on Chlamydia specific antibody responses . However, overall, 86% of the trials achieved results indicating vaccination induced a measurable antibody mediated immune response.
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Siu Research Shows Promise For Vaccine Against Chlamydia In Women
CARBONDALE, Ill. A researcher at Southern Illinois University Carbondale has made key progress in creating a vaccine that could protect against the common sexually transmitted disease chlamydia and possibly other STDs. Vjollca Konjufca, associate professor in the School of Biological Sciences, recently published the results of a study that showed introducing a vaccine through the mouth and into the gut results in an immune response in the female reproductive tract.
A major threat
Chlamydia trachomatis bacteria typically wreak havoc on younger people. If left untreated, chlamydial infections may lead to the development of pelvic inflammatory disease, chronic pelvic pain, hydrosalpinx , endometriosis and infertility. Women with chlamydial infections are at a higher risk for acquiring HIV infections and for developing HPV-associated cervical cancer.
More than 1.7 million cases were reported to the Centers for Disease Control and Prevention in 2018, making it the leading bacterial sexually transmitted infection. But health officials estimate the actual number of cases in United States was almost 2.9 million that year.
About two-thirds of those carrying the disease are not aware of it, meaning it is often left untreated and spreads easily.
The search for a vaccine
Currently, there is no licensed vaccine available to prevent infections of chlamydia, and other than the one for human papillomavirus , vaccines for sexually transmitted infections dont exist.
Unlocking the secret?