HPV vaccine's efficacy comparable in one and three doses
One dose of bivalent HPV vaccine Cervarix might be enough to provide at least short-term protection from infection, according to a study published in Lancet Oncology1. Data from two large clinical trials indicated that women aged 15–25 years who received only one dose of the HPV-16/18 vaccine were protected to a similar extent as subjects who received all three injections.
The HPV vaccine is recommended in three doses but it has the lowest completion rate among recommended vaccinces. "These exciting findings address the fact that nearly two-thirds of people who get HPV vaccines do not get all three doses in a timely manner," Diane Harper of University of Louisville School of Medicine said in a statement.
HPV is responsible for almost all cases of cervical cancer, and vaccination protects against 70% of HPV types. “Knowing that Cervarix offers protection in one dose reassures public health agencies that they are not wasting money when most of their vaccines are given to those who never complete the three-dose series,” added Dr. Harper.
It should be noted that only long-term follow-up of vaccinees will provide the data to inform on whether the rate of protection following a single dose remains comparable to that following three doses, given that for other subunit vaccines, the second and third doses serve to effectively establish long-term memory following the initial dose.
1. Kreimer AR, Struyf F, Del Rosario-Raymundo MR, Hildesheim A, Skinner SR, Wacholder S, Garland SM, Herrero R, David MP, Wheeler CM; Costa Rica Vaccine Trial and the PATRICIA study groups. Efficacy of fewer than three doses of an HPV-16/18 AS04-adjuvanted vaccine: combined analysis of data from the Costa Rica Vaccine and PATRICIA trials. Lancet Oncol 2015; doi: 10.1016/S1470-2045(15)00047-9
WHO prequalifies influenza vaccine made in China
The World Health Organization (WHO) has approved for safety and efficacy an influenza vaccine produced by Hualan Biological Bacterin. It is a second prequalification of a China-made vaccine following JEV vaccine in 2013. The approval means that the vaccine can be obtained by UN agencies.
"WHO prequalification of the Hualan vaccine is another feather in the cap of China's growing vaccine manufacturing industry," Bernhard Schwartländer, WHO representative in China, said in a press release. "The country is set to become one of the preeminent vaccine manufacturers globally."
The company can produce 300 million single-dose vaccines and 50 million three-dose vaccines annually.
BCG vaccine tested in treatment of type 1 diabetes
BCG vaccine has shown potential for treating type 1 diabetes. Scientists at Massachusetts General Hospital have demonstrated that the vaccine elevates levels of the immune modulator TNF, which can eliminate abnormal lymphocytes responsible for the autoimmune disease.
A Phase 1 trial demonstrated a transient return of insulin secretion. In Phase 2, which has been approved by FDA, dosing will be increased in an attempt to create a lasting therapeutic response. 150 adults with long-term type 1 diabetes will receive two injections of BCG or placebo four weeks apart and then one dose annually for a period of four years.
BCG vaccine is used not only against its original target, tuberculosis, but also in treatment of superficial bladder cancer for its ability to nonspecifically boost the immune response against the tumor.
West Nile virus vaccine candidate enters clinical trials
A group at Oregon Health & Science University advanced their West Nile virus vaccine to a Phase 1 trial to be held at Duke University. The incidence of West Nile virus infection has surged in North America. 3 million cases have been reported in the U.S. since 1999, but no vaccine has yet been developed.
The candidate vaccine consists of a virus inactivated by hydrogen peroxide, a platform developed by Najit Technologies. "We believe our vaccine approach will not only be safe and effective for West Nile virus, but it could also provide significant protection against other important human pathogens, including yellow fever, dengue hemorrhagic fever, and, potentially even Ebola," Mark Slifka, Najit's CSO said in a statement.
Group a streptococcus combination vaccine successful in mice
Co-administration of two Streptococcus pyogenes vaccine candidates showed promise in a preclinical setting. Scientists at Griffith University developed a vaccine containing the inactive form of the streptococcal CXC protease (SpyCEP) and combined it with a previously reported candidate, a synthetic peptide J8-DT. In a mouse challenge model, bacterial burden was reduced up to 1,000 fold. The results were published in Journal of Immunology1. SpyCEP is designed to target hypervirulent mutants of S. pyogenes capable of preventing neutrophil chemotaxis by degrading CXC chemokines. When degradation is prevented, J8-DT can direct lymphocytes to the pathogen. Mortality of infections caused by these mutant strains reaches 10-15%.
"We will spend the next six months developing that vaccine at a high level of purity suitable for humans and hope to start a clinical trial next year," Michael Good of Griffith University said in a statement.
Infections by Group A Streptococcus cause 500,000 deaths annually, especially in developing countries of the tropical region. It causes tonsillitis, skin infection and, when left untreated, rheumatic heart disease.
1. Pandey M, Langshaw E, Hartas J, Lam A, Batzloff MR, Good MF. A Synthetic M Protein Peptide Synergizes with a CXC Chemokine Protease To Induce Vaccine-Mediated Protection against Virulent Streptococcal Pyoderma and Bacteremia. J Immunol 2015; 194:5915-25
Gardasil 9 approved in EU
The European Commission has approved the HPV vaccine Gardasil 9 for use in member states. The decision came after the recommendation by the European Medicines Agency in March, which was based of 7 large-scale clinical trials involving >15,000 people. Gardasil 9 was approved by the U.S. Food and Drug Administration in 2014.
The 9-valent vaccine (preventing 90% of cervical cancer and 90% of HPV-related anal cancer as well as 90% of genital warts) protects against the four HPV strains covered by its predecessor Gardasil (consisting of types 6 & 11 for genital warts and 16 & 18 for cancer) and against five additional high-risk HPV types (31, 33, 45, 52 & 58).
MERS vaccine shows promise in a preclinical study
A new candidate vaccine against Middle East Respiratory Syndrome coronavirus (MERS-CoV) is efficacious in a MERS-susceptible mouse model. A recombinant Modified Vaccinia virus Ankara expressing MERS glycoprotein S was administered intramuscularly and subcutaneously, and in both cases elicited CD8+ T-cell response and neutralizing antibodies.
"This demonstrates that our vaccine candidate is both safe and effective. Thus, there is no obvious risk that the resulting immune response might exacerbate rather than prevent the infection," Gerd Sutter of University of Munich and lead author of the study1 said in a press release. The candidate now proceeds to safety testing in human subjects.
MERS-CoV causes infection with influenza-like symptoms but can progress to lethal respiratory disease. It first appeared in 2012 in Saudi Arabia, and most recently caused an outbreak in South Korea with 150 people infected. There is no vaccine against MERS-CoV.
1. Volz A, Kupke A, Song F, Jany S, Fux R, Shams-Eldin H, Schmidt J, Becker C, Eickmann M, Becker S, Sutter G. Protective efficacy of recombinant Modified Vaccinia virus Ankara (MVA) delivering Middle East Respiratory Syndrome coronavirus spike glycoprotein. J Virol 2015; doi: 10.1128/JVI.00614-15
Shortage of volunteers causes fears of failure of Ebola vaccine trials
The Ebola epidemic in West Africa has seen a sharp decline of new cases in the past few months, and scientists worry that there will not be enough volunteers to carry out clinical testing of the available vaccine candidates. In Liberia, there have been no new cases of Ebola since March, and the Liberia trial, originally aimed to test 28,000 subjects, stopped enrolling at 1,500.
The hemorrhagic Ebola virus has killed >11,000 people since the start of the epidemic in 2013. Currently, the last country where new cases are still reported is Guinea. The World Health Organization (WHO) recruits mostly family members and close contacts of the victims.
In response to the setback, WHO prepares a 'blueprint' for potential future outbreaks that outlines a plan for more rapid response in vaccine development and testing.
A therapeutic genital herpes vaccine fails phase 1/2 trial
A therapeutic herpes simplex virus type 2 (HSV-2) vaccine candidate (Vical) failed to meet the primary endpoint in an early clinical study. In a sample of 150 patients, the vaccine performed worse than placebo as assessed by viral shedding. The only benefit was observed in a reduction in genital lesions, the study's secondary endpoint.
The trial tested Vaxfectin-adjuvanted mono- and bivalent vaccines in two steps: an initial dose-escalation cohort followed by efficacy analysis at full dose. "The trial is ongoing and all patients are being followed for safety for 12 months and efficacy for 9 months after their final vaccine dose. During that 9-month period, we will collect additional clinical efficacy data including recurrence rate and lesion rate, which will enable us to determine the appropriate next steps for this program," Vical's CEO Vijay Samant said in a statement.
Genital herpes infection usually has no or mild symptoms but in minority of cases, it can cause painful genital ulcers, encephalitis and blindness. No vaccine is available against HSV.