First Influenza Vaccine That Does Not Need to be Administered by a Health Care Provider

[Posted 4/Oct/2024]

AUDIENCE: Infectious Disease, Family Medicine, Nursing

On September 20, 2024, the U.S. Food and Drug Administration approved FluMist for self- or caregiver-administration. FluMist is approved for the prevention of influenza disease caused by influenza virus subtypes A and B in individuals 2 through 49 years of age. FluMist is sprayed into the nose and has been used safely and effectively for many years. It was initially approved by the FDA in 2003 for use in individuals 5 through 49 years of age, and in 2007, the FDA approved the use of FluMist to include children 2 through 5 years of age. It is the first vaccine to prevent influenza, more commonly known as the flu, that does not need to be administered by a health care provider

"Today's approval of the first influenza vaccine for self- or caregiver-administration provides a new option for receiving a safe and effective seasonal influenza vaccine potentially with greater convenience, flexibility and accessibility for individuals and families," said Peter Marks, M.D., Ph.D., director of the FDA's Center for Biologics Evaluation and Research. "Getting vaccinated each year is the best way to prevent influenza, which causes illness in a substantial proportion of the U.S. population every year and may result in serious complications, including hospitalization and death. This approval adds another option for vaccination against influenza disease and demonstrates the FDA's commitment to advancing public health."

The flu is a common and contagious respiratory disease that is caused by influenza viruses that typically circulate during the fall and winter in the U.S. It can cause mild to severe illness with a range of symptoms that usually appear suddenly, such as body aches, fever, coughing, sore throat, tiredness and a stuffy or runny nose. Flu can be life-threatening and cause serious complications that can lead to hospitalization or death, particularly in high-risk groups such as the elderly, young children and people with certain chronic medical conditions. Each flu season is different and the health impacts can be substantial and vary widely from season to season, with some flu seasons being worse than others. According to the U.S. Centers for Disease Control and Prevention, flu has resulted in about 9.3 million to 41 million illnesses, 100,000 to 710,000 hospitalizations and 4,900 to 51,000 deaths annually between 2010 and 2023. Numerous FDA-approved vaccines are available each flu season to prevent influenza.

FluMist contains a weakened form of live influenza virus strains and is sprayed in the nose. A prescription is still required to receive FluMist. There are now two approved options for receiving FluMist. The vaccine may be administered by a health care provider in a health care setting (including a pharmacy) or it may be administered by the vaccine recipient or a caregiver who is 18 years of age or older.

The most commonly reported side effects of FluMist are fever over 100°F in children 2 through 6 years of age, runny nose and nasal congestion in individuals 2 through 49 years of age and a sore throat in adults 18 through 49 years of age.

For those interested in self- or caregiver-administration, the vaccine manufacturer plans to make the vaccine available through a third-party online pharmacy. Those who choose this option will complete a screening and eligibility assessment when they order FluMist. The third-party pharmacy determines eligibility based on the completed screening and, if it is determined that the intended vaccine recipient is eligible, the pharmacy writes the prescription and ships the vaccine to the address provided by the individual who placed the order. The vaccine can then be administered to the prescribed household member(s) at their convenience. A caregiver should administer FluMist to individuals 2 through 17 years of age, as individuals in this age group should not self-administer the vaccine.

A study was conducted with vaccine recipients and caregivers to evaluate whether the instructions for use were appropriately designed so that recipients and caregivers could safely and effectively use the vaccine.

Vaccine recipients and caregivers who administer FluMist will be sent the vaccine, the Prescribing Information, Information for Patients and their Caregivers and Instructions for Use. The Instructions for Use provides detailed instructions for storage, administration and disposal of FluMist.

The FDA granted this approval of FluMist (Influenza Vaccine Live, Intranasal) to MedImmune LLC.

Source: FDA Approves Nasal Spray Influenza Vaccine for Self- or Caregiver-Administration. FDA. 2024; Published: September, 2024. DOI: FDA.

[Posted 6/Nov/2024]

AUDIENCE: Gastroenterology, Infectious Disease, Internal Medicine

KEY FINDINGS: The results show that CRISPR-Cas13b can be programmed to specifically target and degrade HBV RNAs to reduce HBV replication and protein expression, demonstrating its potential as a novel therapeutic option for chronic HBV infection.

BACKGROUND: New antiviral approaches that target multiple aspects of the HBV replication cycle to improve rates of functional cure are urgently required. HBV RNA represents a novel therapeutic target. Here, we programmed CRISPR-Cas13b endonuclease to specifically target the HBV pregenomic RNA and viral mRNAs in a novel approach to reduce HBV replication and protein expression.

DETAILS: Cas13b CRISPR RNAs (crRNAs) were designed to target multiple regions of HBV pregenomic RNA. Mammalian cells transfected with replication competent wild-type HBV DNA of different genotypes, a HBV-expressing stable cell line, a HBV infection model and a hepatitis B surface antigen (HBsAg)-expressing stable cell line were transfected with PspCas13b-BFP (blue fluorescent protein) and crRNA plasmids, and the impact on HBV replication and protein expression was measured. Wild-type HBV DNA, PspCas13b-BFP and crRNA plasmids were simultaneously hydrodynamically injected into mice, and serum HBsAg was measured. PspCas13b mRNA and crRNA were also delivered to a HBsAg-expressing stable cell line via lipid nanoparticles and the impact on secreted HBsAg determined. The HBV-targeting crRNAs strongly suppressed HBV replication and protein expression in mammalian cells by up to 96% (p <0.0001). HBV protein expression was also reduced in a HBV-expressing stable cell line and in the HBV infection model. CRISPR-Cas13b crRNAs reduced HBsAg expression by 50% (p <0.0001) in vivo. Lipid nanoparticle-encapsulated PspCas13b mRNA reduced secreted HBsAg by 87% (p = 0.0168) in a HBsAg-expressing stable cell line.

Copyright © Elsevier Inc. All rights reserved.

Source: McCoullough, L. C., Fareh, M., Hu, W., et al. (2024). CRISPR-Cas13b-mediated Suppression of HBV Replication and Protein Expression. Journal of Hepatology. 2024; 81(5): 794-805. Published: November, 2024. DOI: 10.1016/j.jhep.2024.05.025.

A Phase 2C, Open-Label, Multicentre, Partially Randomised Controlled Trial

[Posted 27/Aug/2024]

AUDIENCE: Infectious Disease, Family Medicine

KEY FINDINGS: For DS-TB, BPaMZ successfully met the primary efficacy endpoint of sputum culture conversion. The regimen did not meet the key secondary efficacy endpoint due to adverse events resulting in treatment withdrawal. Our study demonstrated the potential for treatment-shortening efficacy of the BPaMZ regimen for DS-TB and DR-TB, providing clinical validation of a murine model widely used to identify such regimens. It also highlights that novel, treatment-shortening TB treatment regimens require an acceptable toxicity and tolerability profile with minimal monitoring in low-resource and high-burden settings. The increased risk of unpredictable severe hepatic adverse events with 4 months of BPaMZ would be a considerable obstacle to implementation of this regimen in settings with high burdens of TB with limited infrastructure for close surveillance of liver biochemistry. Future research should focus on improving the preclinical and early clinical detection and mitigation of safety issues together and further efforts to optimise shorter treatments.

BACKGROUND: The current tuberculosis (TB) drug development pipeline is being re-populated with candidates, including nitroimidazoles such as pretomanid, that exhibit a potential to shorten TB therapy by exerting a bactericidal effect on non-replicating bacilli. Based on results from preclinical and early clinical studies, a four-drug combination of bedaquiline, pretomanid, moxifloxacin, and pyrazinamide (BPaMZ) regimen was identified with treatment-shortening potential for both drug-susceptible (DS) and drug-resistant (DR) TB. This trial aimed to determine the safety and efficacy of BPaMZ. We compared 4 months of BPaMZ to the standard 6 months of isoniazid, rifampicin, pyrazinamide, and ethambutol (HRZE) in DS-TB. 6 months of BPaMZ was assessed in DR-TB.

DETAILS: SimpliciTB was a partially randomised, phase 2c, open-label, clinical trial, recruiting participants at 26 sites in eight countries. Participants aged 18 years or older with pulmonary TB who were sputum smear positive for acid-fast bacilli were eligible for enrolment. Participants with DS-TB had Mycobacterium tuberculosis with sensitivity to rifampicin and isoniazid. Participants with DR-TB had M tuberculosis with resistance to rifampicin, isoniazid, or both. Participants with DS-TB were randomly allocated in a 1:1 ratio, stratified by HIV status and cavitation on chest radiograph, using balanced block randomisation with a fixed block size of four. The primary efficacy endpoint was time to sputum culture-negative status by 8 weeks; the key secondary endpoint was unfavourable outcome at week 52. A non-inferiority margin of 12% was chosen for the key secondary outcome. Safety and tolerability outcomes are presented as descriptive analyses. The efficacy analysis population contained patients who received at least one dose of medication and who had efficacy data available and had no major protocol violations. The safety population contained patients who received at least one dose of medication. Between July 30, 2018, and March 2, 2020, 455 participants were enrolled and received at least one dose of study treatment. 324 (71%) participants were male and 131 (29%) participants were female. 303 participants with DS-TB were randomly assigned to 4 months of BPaMZ (n=150) or HRZE (n=153). In a modified intention-to-treat (mITT) analysis, by week 8, 122 (84%) of 145 and 70 (47%) of 148 participants were culture-negative on 4 months of BPaMZ and HRZE, respectively, with a hazard ratio for earlier negative status of 2.93 (95% CI 2.17-3.96; p<0.0001). Median time to negative culture (TTN) was 6 weeks (IQR 4-8) on 4 months of BPaMZ and 11 weeks (6-12) on HRZE. 86% of participants with DR-TB receiving 6 months of BPaMZ (n=152) reached culture-negative status by week 8, with a median TTN of 5 weeks (IQR 3-7). At week 52, 120 (83%) of 144, 134 (93%) of 144, and 111 (83%) of 133 on 4 months of BPaMZ, HRZE, and 6 months of BPaMZ had favourable outcomes, respectively. Despite bacteriological efficacy, 4 months of BPaMZ did not meet the non-inferiority margin for the key secondary endpoint in the pre-defined mITT population due to higher withdrawal rates for adverse hepatic events. Non-inferiority was demonstrated in the per-protocol population confirming the effect of withdrawals with 4 months of BPaMZ. At least one liver-related treatment-emergent adverse effect (TEAE) occurred among 45 (30%) participants on 4 months of BPaMZ, 38 (25%) on HRZE, and 33 (22%) on 6 months of BPaMZ. Serious liver-related TEAEs were reported by 20 participants overall; 11 (7%) among those on 4 months of BPaMZ, one (1%) on HRZE, and eight (5%) on 6 months of BPaMZ. The most common reasons for discontinuation of trial treatment were hepatotoxicity (ten participants [2%]), increased hepatic enzymes (nine participants [2%]), QTcF prolongation (three participants [1%]), and hypersensitivity (two participants [<1%]).

Copyright © The Author(s). Published by Elsevier Ltd. All rights reserved.

Source: Cevik, M., Thompson, L. C., Upton, C., et al. (2024). Bedaquiline-Pretomanid-Moxifloxacin-Pyrazinamide for Drug-Sensitive and Drug-Resistant Pulmonary Tuberculosis Treatment: A Phase 2C, Open-Label, Multicentre, Partially Randomised Controlled Trial. The Lancet Infectious Diseases. 2024; 24(9): 1003-1014. Published: September, 2024. DOI: 10.1016/S1473-3099(24)00223-8.

A Phase 1, Double-Blind Trial

[Posted 13/Aug/2024]

AUDIENCE: Infectious Disease, Nursing, Ob/Gyn

KEY FINDINGS: CTH522, adjuvanted with CAF01 or CAF09b, is safe and immunogenic, with 85 μg CTH522-CAF01 inducing robust serum IgG binding titres. Intradermal vaccination conferred systemic IgG neutralisation breadth, and topical ocular administration increased ocular IgA formation. These findings indicate CTH522 vaccine regimens against ocular trachoma and urogenital chlamydia for testing in phase 2, clinical trials.

BACKGROUND: There is no vaccine against the major global pathogen Chlamydia trachomatis; its different serovars cause trachoma in the eye or chlamydia in the genital tract. Authors did a clinical trial administering CTH522, a recombinant version of the C trachomatis major outer membrane molecule, in different dose concentrations with and without adjuvant, to establish its safety and immunogenicity when administered intramuscularly, intradermally, and topically into the eye, in prime-boost regimens.

DETAILS: CHLM-02 was a phase 1, double-blind, randomised, placebo-controlled trial at the National Institute for Health Research Imperial Clinical Research Facility, London, UK. Participants were healthy men and non-pregnant women aged 18-45 years, without pre-existing C trachomatis genital infection. Participants were assigned into six groups by the electronic database in a pre-prepared randomisation list (A-F). Participants were randomly assigned (1:1:1:1:1) to each of the groups A-E (12 participants each) and 6 were randomly assigned to group F. Investigators were masked to treatment allocation. Groups A-E received investigational medicinal product and group F received placebo only. Two liposomal adjuvants were compared, CAF01 and CAF09b. The groups were intramuscular 85 µg CTH522-CAF01, or placebo on day 0 and two boosters or placebo at day 28 and 112, and a mucosal recall with either placebo or CTH522 topical ocularly at day 140 (A); intramuscular 85 µg CTH522-CAF01, two boosters at day 28 and 112 with additional topical ocular administration of CTH522, and a mucosal recall with either placebo or CTH522 topical ocularly at day 140 (B); intramuscular 85 µg CTH522-CAF01, two boosters at day 28 and 112 with additional intradermal administration of CTH522, and a mucosal recall with either placebo or CTH522 topical ocularly at day 140 (C); intramuscular 15 µg CTH522-CAF01, two boosters at day 28 and 112, and a mucosal recall with either placebo or CTH522 topical ocularly at day 140 (D); intramuscular 85 µg CTH522-CAF09b, two boosters at day 28 and 112, and a mucosal recall with either placebo or CTH522 topical ocularly at day 140 (E); intramuscular placebo (F). The primary outcome was safety; the secondary outcome (humoral immunogenicity) was the percentage of trial participants achieving anti-CTH522 IgG seroconversion, defined as four-fold and ten-fold increase over baseline concentrations. Analyses were done as intention to treat and as per protocol. The trial is registered with ClinicalTrials.gov, NCT03926728, and is complete. Between Feb 17, 2020 and Feb 22, 2022, of 154 participants screened, 65 were randomly assigned, and 60 completed the trial (34 [52%] of 65 women, 46 [71%] of 65 White, mean age 26.8 years). No serious adverse events occurred but one participant in group A2 discontinued dosing after having self-limiting adverse events after both placebo and investigational medicinal product doses. Study procedures were otherwise well tolerated; the majority of adverse events were mild to moderate, with only seven (1%) of 865 reported as grade 3 (severe). There was 100% four-fold seroconversion rate by day 42 in the active groups (A-E) and no seroconversion in the placebo group. Serum IgG anti-CTH522 titres were higher after 85 µg CTH522-CAF01 than 15 µg, although not significantly (intention-to-treat median IgG titre ratio groups A-C:D=5.6; p=0.062), with no difference after three injections of 85 µg CTH522-CAF01 compared with CTH522-CAF09b (group E). Intradermal CTH522 (group C) induced high titres of serum IgG anti-CTH522 neutralising antibodies against serovars B (trachoma) and D (urogenital). Topical ocular CTH522 (group B) at day 28 and 112 induced higher total ocular IgA compared with baseline (p0.001). Participants in all active vaccine groups, particularly groups B and E, developed cell mediated immune responses against CTH522.

Copyright © Elsevier Ltd. All rights reserved.

Source: Pollock, K. M., Borges, A. H., Cheeseman, H. M., et al. (2024). An Investigation of Trachoma Vaccine Regimens by the Chlamydia Vaccine CTH522 Administered With Cationic Liposomes in Healthy Adults (CHLM-02): A Phase 1, Double-Blind Trial. The Lancet. 2024; 24(8): 829-844. Published: August, 2024. DOI: 10.1016/S1473-3099(24)00147-6.

A Retrospective Cohort Study

[Posted 6/Jul/2024]

AUDIENCE: Ob/Gyn, Infectious Disease

KEY FINDINGS: Among predominantly asymptomatic STIs, M. genitalium detected at baseline visit was significantly associated with low birth weight, while T. vaginalis detected at the repeat visit in later pregnancy was significantly associated with preterm birth. Further research is warranted to study the impact of etiological testing of STIs at more than one antenatal visit and empirical treatment on pregnancy outcomes.

BACKGROUND: There is a high prevalence and incidence rate of asymptomatic sexually transmitted infections (STIs) during pregnancy in adolescent girls and young women in Africa. The association between STIs and pregnancy outcomes in a hyperepidemic HIV setting has not been well described.

DETAILS: Pregnant women, HIV-1 negative and <28 weeks' gestation at three primary health clinics in KwaZulu-Natal, South Africa were enrolled from February 2017 to March 2018. Vaginal swabs collected at the first and later antenatal visits were stored and retrospectively tested for HSV-2, Trichomonas vaginalis, Chlamydia trachomatis and Neisseria gonorrhoeae at the end of the study. The association between STIs detected at first and later antenatal visits and pregnancy outcome was assessed using multivariable logistic regression models adjusted for maternal age and treatment received for symptomatic STIs. Testing positive Mycoplasma genitalium at the first antenatal visit was significantly associated with low birth weight (odds ratio [OR] 5.22; 95% confidence interval [CI]: 1.10-15.98). Testing positive for T. vaginalis at the repeat visit was significantly associated with preterm births (OR 2.37; 95% CI: 1.11-5.03), low birth weight (OR 2.56; 1.16-5.63) and a composite adverse pregnancy outcome (OR 2.11; 95% CI: 1.09-4.08). Testing positive for HSV-2 at the repeat visit was also likely associated with experiencing a preterm birth or any adverse pregnancy outcome (OR 3.39; 95% CI: 0.86-13.3) (P = 0.096).

Copyright © John Wiley & Sons, Inc. All rights reserved

Source: Govender, V., Moodley, D., Naidoo, M., et al. (2024). Sexually Transmitted Infections in Pregnancy and Adverse Pregnancy Outcomes: A Retrospective Cohort Study. International Journal of Gynecology and Obstetrics. 2024; Published: July, 2024. DOI: 10.1002/ijgo.15529.

An Individual Participant Data Meta-Analysis

[Posted 26/Jun/2024]

AUDIENCE: Infectious Disease, Family Medicine

KEY FINDINGS: The majority of people in the community who have pulmonary tuberculosis do not report cough, a quarter report no tuberculosis-suggestive symptoms at all, and a quarter of those not reporting any cough have positive sputum smears, suggesting infectiousness. In high-incidence settings, subclinical tuberculosis could contribute considerably to the tuberculosis burden and to Mycobacterium tuberculosis transmission.

BACKGROUND: Subclinical pulmonary tuberculosis, which presents without recognisable symptoms, is frequently detected in community screening. However, the disease category is poorly clinically defined. We explored the prevalence of subclinical pulmonary tuberculosis according to different case definitions.

DETAILS: Authors did a one-stage individual participant data meta-analysis of nationally representative surveys that were conducted in countries with high incidence of tuberculosis between 2007 and 2020, that reported the prevalence of pulmonary tuberculosis based on chest x-ray and symptom screening in participants aged 15 years and older. Screening and diagnostic criteria were standardised across the surveys, and tuberculosis was defined by positive Mycobacterium tuberculosis sputum culture. We estimated proportions of subclinical tuberculosis for three case definitions: no persistent cough (ie, duration >=2 weeks), no cough at all, and no symptoms (ie, absence of cough, fever, chest pain, night sweats, and weight loss), both unadjusted and adjusted for false-negative chest x-rays and uninterpretable culture results. Authors identified 34 surveys, of which 31 were eligible. Individual participant data were obtained and included for 12 surveys (620 682 participants) across eight countries in Africa and four in Asia. Data on 602 863 participants were analysed, of whom 1944 had tuberculosis. The unadjusted proportion of subclinical tuberculosis was 59.1% (n=1149/1944; 95% CI 55.8-62.3) for no persistent cough and 39.8% (773/1944; 36.6-43.0) for no cough of any duration. The adjusted proportions were 82.8% (95% CI 78.6-86.6) for no persistent cough and 62.5% (56.6-68.7) for no cough at all. In a subset of four surveys, the proportion of participants with tuberculosis but without any symptoms was 20.3% (n=111/547; 95% CI 15.5-25.1) before adjustment and 27.7% (95% CI 21.0-36.4) after adjustment. Tuberculosis without cough, irrespective of its duration, was more frequent among women (no persistent cough: adjusted odds ratio 0.79, 95% CI 0.63-0.97; no cough: adjusted odds ratio 0.76, 95% CI 0.62-0.93). Among participants with tuberculosis, 29.1% (95% CI 25.2-33.3) of those without persistent cough and 23.1% (18.8-27.4) of those without any cough had positive smear examinations.

Copyright © Elsevier Ltd. All rights reserved.

Source: Stuck, L., Klinkenberg, E., Ali, N. A., et al. (2024). Prevalence of Subclinical Pulmonary Tuberculosis in Adults in Community Settings: An Individual Participant Data Meta-Analysis. The Lancet. 2024; Published: June, 2024. DOI: 10.1016/S1473-3099(24)00011-2.