Neutralizing antibodies after the third COVID-19 vaccination in healthcare workers with or without breakthrough infection.

BACKGROUND: Vaccinations against the SARS-CoV-2 are still crucial in combating the ongoing pandemic that has caused more than 700 million infections and claimed almost 7 million lives in the past four years. Omicron (B.1.1.529) variants have incurred mutations that challenge the protection against infection and severe disease by the current vaccines, potentially compromising vaccination efforts. METHODS: We analyzed serum samples taken up to 9 months post third dose from 432 healthcare workers. Enzyme-linked immunosorbent assays (ELISA) and microneutralization tests (MNT) were used to assess the prevalence of vaccine-induced neutralizing antibodies against various SARS-CoV-2 Omicron variants. RESULTS: In this serological analysis we show that SARS-CoV-2 vaccine combinations of BNT162b2, mRNA-1273, and ChAdOx1 mount SARS-CoV-2 binding and neutralizing antibodies with similar kinetics, but with differing neutralization capabilities. The most recent Omicron variants, BQ.1.1 and XBB.1.5, show a significant increase in the ability to escape vaccine and infection-induced antibody responses. Breakthrough infections in thrice vaccinated adults were seen in over 50% of the vaccinees, resulting in a stronger antibody response than without infection. CONCLUSIONS: Different three-dose vaccine combinations seem to induce considerable levels of neutralizing antibodies against most SARS-CoV-2 variants. However, the ability of the newer variants BQ1.1 and XBB 1.5 to escape vaccine-induced neutralizing antibody responses underlines the importance of updating vaccines as new variants emerge.

During the COVID-19 pandemic, mass vaccination efforts against SARS-CoV-2 infection have provided effective protection against the virus and helped reduce the severity of symptoms in infected individuals. However, it is not well established whether the existing vaccines can provide the same protection against new and emerging SARS-CoV-2 variants that develop over time as the virus evolves. In this study, we tested combinations of three-dose COVID-19 vaccines given in random order to protect against all SARS-CoV-2 variants in circulation including the newest being Omicron variants. We demonstrate that more than half of the population who received the three-dose vaccine combinations were infected with SARS-CoV-2 Omicron variants after receiving the last vaccine dose. These findings indicate the need to develop new vaccine candidates against emerging SARS-CoV-2 variants.

ISOM 2023 Research Panel 5: Interventions- Vaccines and prevention, medical and surgical treatment, and impact of COVID-19 pandemic.

OBJECTIVES: To identify and synthesize key research advances from the literature published between 2019 and 2023 on the advances in preventative measures, and medical and surgical treatment of uncomplicated otitis media (OM) including the impact of the COVID-19 pandemic on OM management. DATA SOURCES: Medline (PubMed), Embase, and the Cochrane Library. REVIEW METHODS: All relevant original articles published in English between June 2019 and February 2023 were identified. Studies related to guideline adherence, impact of treatment on immune response and/or microbiology, tympanoplasty, Eustachian tube balloon dilatation, mastoidectomy procedures, and those focusing on children with Down's syndrome or cleft palate were excluded. MAIN FINDINGS: Of the 9280 unique records screened, 64 were eligible for inclusion; 23 studies related to medical treatment, 20 to vaccines, 13 to surgical treatment, 6 to prevention (excl. vaccines) and 2 to the impact of COVID-19 on OM management. The level of evidence was judged 2 in 11 studies (17.2 %) and 3 or 4 in the remaining 53 studies (82.8 %) mainly due to the observational design, study limitations or low sample sizes. Some important advances in OM management have been made in recent years. Video discharge instructions detailing the identification and management of pain and fever for parents of children with acute otitis media (AOM) was more effective than paper instructions in reducing symptomatology; compared to placebo, levofloxacin solution was more effective for treating chronic suppurative otitis media, whereas AOM recurrences during two years of follow-up did not differ between children with recurrent AOM who received tympanostomy tube (TT) insertion or medical management. Further, novel pneumococcal conjugate vaccines (PCV) schedules for preventing OM in Aboriginal children appeared ineffective, and a protein-based pneumococcal vaccine had no added value over PCV13 for preventing AOM in native American infants. During the COVID-19 pandemic, a decline in OM and TT case volumes and complications was observed. IMPLICATION FOR PRACTICE AND FUTURE RESEARCH: Whether the observed impact of the COVID-19 pandemic on OM management extends to the post-pandemic era is uncertain. Furthermore, the impact of the pandemic on the conduct of urgently needed prospective methodologically rigorous interventional studies aimed at improving OM prevention and treatment remains to be elucidated since the current report consisted of studies predominantly conducted in the pre-pandemic era.

Streptococcus salivarius Probiotics to Prevent Acute Otitis Media in Children: A Randomized Clinical Trial.

Importance: New approaches for the prevention of acute otitis media (AOM), the most common reason for antibiotic use in children, are needed. Objective: To assess the efficacy of the Streptococcus salivarius K12 oral probiotics in the primary prevention of AOM. Design, Setting, and Participants: This double-blind, randomized placebo-controlled clinical trial was conducted from August 1, 2020, to May 31, 2021, at 50 day care centers in the Oulu region of Finland. A total of 827 children aged 1 to 6 years attending day care were included. The exclusion criteria consisted of ongoing antimicrobial prophylaxis or immunodeficiency. The follow-up time was 6 months and was completed on May 31, 2021. Data were analyzed from October 24, 2022, to September 16, 2023, based on intention to treat. Intervention: Eligible participants were randomly allocated to receive 1 daily dose of a S salivarius K12 product or placebo every evening for 6 months. A daily dose was defined as 1 sachet of soluble oral powder for children younger than 3 years or 1 chewable tablet for children 3 years or older containing 1 × 109 colony-forming units of S salivarius K12. Main Outcomes and Measures: The primary outcome was the proportion of children with at least 1 episode of AOM requiring antimicrobial therapy within 6 months of randomization. All physician visits and purchases of antimicrobial drugs were retrieved from the electronic national medical record and prescription register. The primary outcome was met if the legal guardian had purchased an antimicrobial prescription for AOM. Results: A total of 827 children with a mean (SD) age of 4.1 (1.6) years (433 boys [52.4%]) were randomized to S salivarius K12 oral products (n = 413) or placebo (n = 414). Thirty-four children (8.2%) in the S salivarius group and 24 children (5.8%) in the placebo group experienced at least 1 episode of AOM requiring antimicrobial therapy during the 6-month follow-up period (relative risk, 1.42 [95% CI, 0.86-2.34]; proportion difference, -2.44% [95% CI, -5.94% to 1.09%]; P = .17). Time to first AOM episode did not differ between the groups (174 [95% CI, 171-177] days in the S salivarius group vs 176 [95% CI, 173-179] days in the placebo group; P = .18). Conclusions and Relevance: In this randomized placebo-controlled clinical trial, the daily use of the S salivarius K12 products for 6 months did not reduce the occurrence of AOM. New approaches for primary prevention of AOM among children are needed. Trial Registration: ClinicalTrialsRegister.eu Identifier: 2020-001076-14.

Parental experiences and opinions regarding the management of acute otitis media in Finland-a comparative questionnaire between 2006 and 2019.

BACKGROUND: Treatment guidelines for acute otitis media (AOM) have changed over the past 20 years. Watchful waiting is often recommended as an option for antibiotic treatment and the use of proper pain medication is emphasised. OBJECTIVE: To study parental experiences and opinions regarding the management of AOM and compare our findings with our previous questionnaire submitted in 2006. METHODS: We sent an online survey link through day-care centres and Facebook parental groups in Turku area. Children <4 years of age attending day care were included in the analysis. We asked about the child's history of AOM, parental opinions about AOM treatment, and antibiotic resistance. Results of 2019 were compared with those of 2006. RESULTS: Altogether 84% (320/381) and 83% (568/681) of children had had at least 1 episode of AOM in 2019 and 2006, respectively. In 2019, more children had been treated without antibiotics (30% vs. 13%, P < 0.001) and fewer parents thought that antibiotics are necessary for the treatment of AOM (70% vs. 85%, P < 0.001) compared with 2006. The use and knowledge of painkillers had increased over the past 13 years. Painkillers had been given at least once to 93% (296/320) of children in 2019 and 80% (441/552) of children in 2006 (P < 0.001). CONCLUSIONS: Today, more parents accept watchful waiting as a treatment option for AOM and give painkillers to their children, which indicates that the education about optimal management of AOM has reached parents.

Ear infection, or acute otitis media (AOM), is one of the most common infections in young children. Studies have shown that antibiotics are effective in treating AOM, but some children may recover well without antibiotics. Antibiotic use may cause adverse events and increase bacterial resistance. We asked Finnish parents for their experiences and opinions regarding AOM management. We sent the same questionnaire in 2006 and 2019 and compared the responses. We found that more children had been treated without antibiotics in 2019, which is in line with the changes in clinical practice guidelines. We also found that parents had given painkillers more often in 2019 than in 2006.

Coronavirus spike protein-specific antibodies indicate frequent infections and reinfections in infancy and among BNT162b2-vaccinated healthcare workers.

The prevalence of seasonal human coronavirus (HCoV) infections in early childhood and adults has not been well analyzed in longitudinal serological studies. Here we analyzed the changes in HCoV (229E, HKU1, NL63, OC43, MERS, and SARS-CoV-2) spike-specific antibody levels in follow-up serum specimens of 140 children at the age of 1, 2, and 3 years, and of 113 healthcare workers vaccinated for Covid-19 with BNT162b2-vaccine. IgG antibody levels against six recombinant HCoV spike subunit 1 (S1) proteins were measured by enzyme immunoassay. We show that by the age of three years the cumulative seropositivity for seasonal HCoVs increased to 38-81% depending on virus type. BNT162b2 vaccinations increased anti-SARS-CoV-2 S1 antibodies, but no increase in seasonal coronavirus antibodies associated with vaccinations. In healthcare workers (HCWs), during a 1-year follow-up, diagnostic antibody rises were seen in 5, 4 and 14% of the cases against 229E, NL63 and OC43 viruses, respectively, correlating well with the circulating HCoVs. In 6% of the HCWs, a diagnostic antibody rise was seen against S1 of HKU1, however, these rises coincided with anti-OC43 S1 antibody rises. Rabbit and guinea pig immune sera against HCoV S1 proteins indicated immunological cross-reactivity within alpha-CoV (229E and NL63) and beta-CoV (HKU1 and OC43) genera.

Enterovirus D68 Outbreak in Children, Finland, August-September 2022.

We observed an intense enterovirus D68 outbreak in children in southwest Finland in August-September 2022. We confirmed enterovirus D68 infection in 56 children hospitalized for respiratory illnesses and in 1 child with encephalitis but were not able to test all suspected patients. Continuing surveillance for enterovirus D68 is needed.

Persistent T cell-mediated immune responses against Omicron variants after the third COVID-19 mRNA vaccine dose.

Introduction: The prime-boost COVID-19 mRNA vaccination strategy has proven to be effective against severe COVID-19 disease and death. However, concerns have been raised due to decreasing neutralizing antibody levels after COVID-19 vaccination and due to the emergence of new immuno-evasive SARS-CoV-2 variants that may require additional booster vaccinations. Methods: In this study, we analyzed the humoral and cell-mediated immune responses against the Omicron BA.1 and BA.2 subvariants in Finnish healthcare workers (HCWs) vaccinated with three doses of COVID-19 mRNA vaccines. We used enzyme immunoassay and microneutralization test to analyze the levels of SARS-CoV-2 specific IgG antibodies in the sera of the vaccinees and the in vitro neutralization capacity of the sera. Activation induced marker assay together with flow cytometry and extracellular cytokine analysis was used to determine responses in SARS-CoV-2 spike protein stimulated PBMCs. Results: Here we show that within the HCWs, the third mRNA vaccine dose recalls both humoral and T cell-mediated immune responses and induces high levels of neutralizing antibodies against Omicron BA.1 and BA.2 variants. Three weeks after the third vaccine dose, SARS-CoV-2 wild type spike protein-specific CD4+ and CD8+ T cells are observed in 82% and 71% of HCWs, respectively, and the T cells cross-recognize both Omicron BA.1 and BA.2 spike peptides. Although the levels of neutralizing antibodies against Omicron BA.1 and BA.2 decline 2.5 to 3.8-fold three months after the third dose, memory CD4+ T cell responses are maintained for at least eight months post the second dose and three months post the third vaccine dose. Discussion: We show that after the administration of the third mRNA vaccine dose the levels of both humoral and cell-mediated immune responses are effectively activated, and the levels of the spike-specific antibodies are further elevated compared to the levels after the second vaccine dose. Even though at three months after the third vaccine dose antibody levels in sera decrease at a similar rate as after the second vaccine dose, the levels of spike-specific CD4+ and CD8+ T cells remain relatively stable. Additionally, the T cells retain efficiency in cross-recognizing spike protein peptide pools derived from Omicron BA.1 and BA.2 subvariants. Altogether our results suggest durable cellmediated immunity and protection against SARS-CoV-2.

Strong Neutralizing Antibody Responses to SARS-CoV-2 Variants Following a Single Vaccine Dose in Subjects With Previous SARS-CoV-2 Infection.

Background: Previous severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection primes the immune system; thus individuals who have recovered from infection have enhanced immune responses to subsequent vaccination (hybrid immunity). However, it remains unclear how well hybrid immunity induced by severe or mild infection can cross-neutralize emerging variants. We aimed to compare the strength and breadth of antibody responses in vaccinated recovered and uninfected subjects. Methods: We measured spike-specific immunoglobulin (Ig)G and neutralizing antibodies (NAbs) from vaccinated subjects including 320 with hybrid immunity and 20 without previous infection. From 29 subjects with a previous severe or mild infection, we also measured NAb responses against Alpha (B.1.1.7), Beta (B.1.351), Delta (B.1.617.2), and Omicron (B.1.1.529/BA.1) variants following vaccination. Results: A single vaccine dose induced 2-fold higher anti-spike IgG concentrations and up to 4-fold higher neutralizing potency of antibodies in subjects with a previous infection compared with vaccinated subjects without a previous infection. Hybrid immunity was more enhanced after a severe than a mild infection, with sequentially decreasing NAb titers against Alpha, Beta, Delta, and Omicron variants. We found similar IgG concentrations in subjects with a previous infection after 1 or 2 vaccine doses. Conclusions: Hybrid immunity induced strong IgG responses, particularly after severe infection. However, the NAb titers were low against heterologous variants, especially against Omicron.

Long-Lasting T Cell Responses in BNT162b2 COVID-19 mRNA Vaccinees and COVID-19 Convalescent Patients.

The emergence of novel variants of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has made it more difficult to prevent the virus from spreading despite available vaccines. Reports of breakthrough infections and decreased capacity of antibodies to neutralize variants raise the question whether current vaccines can still protect against COVID-19 disease. We studied the dynamics and persistence of T cell responses using activation induced marker (AIM) assay and Th1 type cytokine production in peripheral blood mononuclear cells obtained from BNT162b2 COVID-19 mRNA vaccinated health care workers and COVID-19 patients. We demonstrate that equally high T cell responses following vaccination and infection persist at least for 6 months against Alpha, Beta, Gamma, and Delta variants despite the decline in antibody levels.

Comparative analysis of COVID-19 vaccine responses and third booster dose-induced neutralizing antibodies against Delta and Omicron variants.

Two COVID-19 mRNA (of BNT162b2, mRNA-1273) and two adenovirus vector vaccines (ChAdOx1 and Janssen) are licensed in Europe, but optimization of regime and dosing is still ongoing. Here we show in health care workers (n = 328) that two doses of BNT162b2, mRNA-1273, or a combination of ChAdOx1 adenovirus vector and mRNA vaccines administrated with a long 12-week dose interval induce equally high levels of anti-SARS-CoV-2 spike antibodies and neutralizing antibodies against D614 and Delta variant. By contrast, two doses of BNT162b2 with a short 3-week interval induce 2-3-fold lower titers of neutralizing antibodies than those from the 12-week interval, yet a third BNT162b2 or mRNA-1273 booster dose increases the antibody levels 4-fold compared to the levels after the second dose, as well as induces neutralizing antibody against Omicron BA.1 variant. Our data thus indicates that a third COVID-19 mRNA vaccine may induce cross-protective neutralizing antibodies against multiple variants.

Vaccine-Induced Antibody Responses against SARS-CoV-2 Variants-Of-Concern Six Months after the BNT162b2 COVID-19 mRNA Vaccination.

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants has raised concern about increased transmissibility, infectivity, and immune evasion from a vaccine and infection-induced immune responses. Although COVID-19 mRNA vaccines have proven to be highly effective against severe COVID-19 disease, the decrease in vaccine efficacy against emerged Beta and Delta variants emphasizes the need for constant monitoring of new virus lineages and studies on the persistence of vaccine-induced neutralizing antibodies. To analyze the dynamics of COVID-19 mRNA vaccine-induced antibody responses, we followed 52 health care workers in Finland for 6 months after receiving two doses of BNT162b2 vaccine with a 3-week interval. We demonstrate that, although anti-S1 antibody levels decrease 2.3-fold compared to peak antibody levels, anti-SARS-CoV-2 antibodies persist for months after BNT162b2 vaccination. Variants D614G, Alpha, and Eta are neutralized by sera of 100% of vaccinees, whereas neutralization of Delta is 3.8-fold reduced and neutralization of Beta is 5.8-fold reduced compared to D614G. Despite this reduction, 85% of sera collected 6 months postvaccination neutralizes Delta variant. IMPORTANCE A decrease in vaccine efficacy against emerging SARS-CoV-2 variants has increased the importance of assessing the persistence of SARS-CoV-2 spike protein-specific antibodies and neutralizing antibodies. Our data show that after 6 months post two doses of BNT162b2 vaccine, antibody levels decrease yet remain detectable and capable of neutralizing emerging variants. By monitoring the vaccine-induced antibody responses, vaccination strategies and administration of booster doses can be optimized.

Low pre-vaccination SARS-CoV-2 seroprevalence in Finnish health care workers: a prospective cohort study.

BACKGROUND: Health care workers are at risk of acquiring SARS-CoV-2 infection. Our aim was to study the prevalence of SARS-CoV-2 nucleoprotein and spike protein specific antibodies in health care workers with occupational exposure to COVID-19 in Turku, Finland, from May to December 2020. METHODS: Health care workers of Turku University Hospital units caring for COVID-19 patients or handling clinical SARS-CoV-2 samples were invited to participate in the study. The presence of SARS-CoV-2 nucleoprotein and spike protein specific IgG antibodies were analysed with in-house enzyme immunoassay. RESULTS: At study enrolment, only one of the 222 (0.5%) study participants was seropositive for SARS-CoV-2 protein specific antibodies. Two additional study participants (2/222, 0.9%) seroconverted during the follow-up. All these participants were diagnosed with a RT-PCR-positive COVID-19 infection before turning seropositive. CONCLUSION: In our study population, the prevalence of SARS-CoV-2 seropositivity remained low. The absence of seropositive cases without previous RT-PCR confirmed infections demonstrate good access to diagnostics. In addition to high vaccine coverage, high standards of infection prevention practices and use of standard personal protective equipment seem sufficient in preventing occupational SARS-CoV-2 infection in a setting with low number of circulating virus. However, it remains unclear whether similar protective practices would also be effective against more transmissible SARS-CoV-2 variants.

COVID-19 mRNA vaccine induced antibody responses against three SARS-CoV-2 variants.

As SARS-CoV-2 has been circulating for over a year, dozens of vaccine candidates are under development or in clinical use. The BNT162b2 mRNA COVID-19 vaccine induces spike protein-specific neutralizing antibodies associated with protective immunity. The emergence of the B.1.1.7 and B.1.351 variants has raised concerns of reduced vaccine efficacy and increased re-infection rates. Here we show, that after the second dose, the sera of BNT162b2-vaccinated health care workers (n = 180) effectively neutralize the SARS-CoV-2 variant with the D614G substitution and the B.1.1.7 variant, whereas the neutralization of the B.1.351 variant is five-fold reduced. Despite the reduction, 92% of the seronegative vaccinees have a neutralization titre of >20 for the B.1.351 variant indicating some protection. The vaccinees' neutralization titres exceeded those of recovered non-hospitalized COVID-19 patients. Our work provides evidence that the second dose of the BNT162b2 vaccine induces cross-neutralization of at least some of the circulating SARS-CoV-2 variants.

Panel 1: Biotechnology, biomedical engineering and new models of otitis media.

OBJECTIVE: To summarize recently published key articles on the topics of biomedical engineering, biotechnology and new models in relation to otitis media (OM). DATA SOURCES: Electronic databases: PubMed, Ovid Medline, Cochrane Library and Clinical Evidence (BMJ Publishing). REVIEW METHODS: Articles on biomedical engineering, biotechnology, material science, mechanical and animal models in OM published between May 2015 and May 2019 were identified and subjected to review. A total of 132 articles were ultimately included. RESULTS: New imaging technologies for the tympanic membrane (TM) and the middle ear cavity are being developed to assess TM thickness, identify biofilms and differentiate types of middle ear effusions. Artificial intelligence (AI) has been applied to train software programs to diagnose OM with a high degree of certainty. Genetically modified mice models for OM have further investigated what predisposes some individuals to OM and consequent hearing loss. New vaccine candidates protecting against major otopathogens are being explored and developed, especially combined vaccines, targeting more than one pathogen. Transcutaneous vaccination against non-typeable Haemophilus influenzae has been successfully tried in a chinchilla model. In terms of treatment, novel technologies for trans-tympanic drug delivery are entering the clinical domain. Various growth factors and grafting materials aimed at improving healing of TM perforations show promising results in animal models. CONCLUSION: New technologies and AI applications to improve the diagnosis of OM have shown promise in pre-clinical models and are gradually entering the clinical domain. So are novel vaccines and drug delivery approaches that may allow local treatment of OM. IMPLICATIONS FOR PRACTICE: New diagnostic methods, potential vaccine candidates and the novel trans-tympanic drug delivery show promising results, but are not yet adapted to clinical use.

Smartphone Otoscopy Performed by Parents.

Introduction:Implementation of pediatric telemedicine has been emphasized. We examined whether parents could perform smartphone otoscopy for the diagnosis of otitis media.Materials and Methods:We included children (6-35 months) attending day care with at least one episode of acute otitis media (AOM) within 90 days of the study entry. The timing for a teaching intervention was randomized. In the immediate teaching group, parents were taught smartphone otoscopy and cerumen was removed at the first visit. The delayed teaching group received the teaching intervention after 1 week's independent use. During the 60 study days, parents performed home examinations. The main outcome, the diagnostic quality of the tympanic membrane videos to determine healthy ear, otitis media with effusion (OME) and AOM diagnoses was measured with a structured video analysis independently by three physicians. Parents' experience was measured with a questionnaire.Results:AOM could be detected or excluded in 87% (609/699) of the videos during acute symptoms. After the teaching intervention, healthy ear, OME, or AOM could be diagnosed in 40% (521/1,293) of the videos. During the first week's intervention, one of the three diagnoses was attained in 33% (50/153) and in 12% (22/179) of the videos in the immediate and delayed teaching group, respectively (p < 0.001). The performance of the smartphone otoscopy examination was easy in 85% (35/41) of families.Discussion:After been taught, parents are able to perform smartphone otoscopy for the remote detection or exclusion of AOM.Conclusions:Future studies should assess the clinical usefulness of parent-performed smartphone otoscopy.

Adaptation of pain scales for parent observation: are pain scales and symptoms useful in detecting pain of young children with the suspicion of acute otitis media?

BACKGROUND: The assessment of ear pain is challenging in young, mostly preverbal children. Our aim was to investigate whether pain scales are useful tools for parents to detect pain in their young children with the suspicion of acute otitis media (AOM), and to assess associations between 16 symptoms and the severity of pain. METHODS: This cross-sectional study included 426 children (6-35 months) with symptoms suggestive of AOM. We surveyed symptoms and pain via parental interview. As part of the interview, parents assessed their child's pain by using two pain scales: The Faces Pain Scale-Revised (FPS-R) and the Face, Legs, Activity, Cry, Consolability (FLACC) Scale. The outcome of interest was moderate/severe pain. We used the χ2 test or Fisher's test as applicable to compare the severity of pain between three parental pain assessment methods (the parental interview, the FPS-R and the FLACC Scale). We also used multivariable logistic regression models to study the association between the severity of pain and AOM and to study the association between symptoms and the severity of pain. RESULTS: In children with AOM (n = 201), pain was assessed by parents as moderate/severe in 65% via interview; 90% with the FPS-R; and 91% with the FLACC Scale (P < 0.001). In children without AOM (n = 225), the percentages were 56, 83 and 88%, respectively (P < 0.001). Between children with and without AOM, the occurrence of moderate/severe pain did not differ with any of the pain evaluation methods. Of symptoms, ear pain reported by child and restless sleep were significantly associated with moderate/severe pain, regardless of the pain evaluation method. CONCLUSIONS: It seems that nearly all the children with respiratory tract infection, either with or without AOM, might suffer from moderate/severe pain. Without pain scales, parents may underestimate their child's pain. Of symptoms, ear pain reported by child and restless sleep might indicate pain in children with respiratory tract infection. We suggest that the adaptation of pain scales for parent observation is a possibility in children with respiratory tract infection which, however, requires further studies. TRIAL REGISTRATION: www.clinicaltrials.gov , identifier NCT00299455 . Date of registration: March 3, 2006.

Impact of Antimicrobial Treatment for Acute Otitis Media on Carriage Dynamics of Penicillin-Susceptible and Penicillin-Nonsusceptible Streptococcus pneumoniae.

Background: Despite concerns that antimicrobial treatment of prevalent infections may select for drug-resistant bacteria, the effects of antimicrobial treatment on colonization dynamics have not been well quantified. Methods: We measured impacts of antimicrobial treatment on nasopharyngeal carriage of penicillin-susceptible Streptococcus pneumoniae (PSSP) and penicillin-nonsusceptible (PNSP) lineages at the end of treatment and 15, 30, and 60 days after treatment in a previously conducted randomized, double-blinded, placebo-controlled trial of amoxicillin-clavulanate for stringently defined acute otitis media. Results: In intention-to-treat analyses, immediate treatment with amoxicillin-clavulanate reduced PSSP carriage prevalence by 88% (95% confidence interval [CI], 76%-96%) at the end of treatment and by 27% (-3%-49%) after 60 days but did not alter PNSP carriage prevalence. By the end of treatment, 7% of children who carried PSSP at enrollment remained colonized in the amoxicillin-clavulanate arm, compared with 61% of PSSP carriers who received placebo; impacts of amoxicillin-clavulanate persisted at least 60 days after treatment among children who carried PSSP at enrollment. Amoxicillin-clavulanate therapy reduced PSSP acquisition by >80% over 15 days. Among children who carried PNSP at enrollment, no impacts on carriage prevalence of S. pneumoniae, PSSP, or PNSP were evident at follow-up visits. Conclusions: Although the absolute risk of carrying PNSP was unaffected by treatment, antimicrobial therapy conferred a selective impact on colonizing pneumococci by accelerating clearance and delaying acquisition of PSSP.

Pneumococcal Phenotype and Interaction with Nontypeable Haemophilus influenzae as Determinants of Otitis Media Progression.

All-cause otitis media (OM) incidence has declined in numerous settings following introduction of pneumococcal conjugate vaccines (PCVs) despite increases in carriage of nonvaccine pneumococcal serotypes escaping immune pressure. To understand the basis for the declining incidence, we assessed the intrinsic capacity of pneumococcal serotypes to cause OM independently and in polymicrobial infections involving nontypeable Haemophilus influenzae (NTHi) using samples obtained from middle ear fluid and nasopharyngeal cultures before PCV7/13 rollout. Data included samples from OM episodes (11,811) submitted for cultures during a 10-year prospective study in southern Israel and nasopharyngeal samples (1,588) from unvaccinated asymptomatic children in the same population. We compared data representing pneumococcal serotype diversity across carriage and disease isolates with and without NTHi coisolation. We also measured associations between the pneumococcal phenotype and the rate of progression from colonization to OM in the presence and absence of NTHi. Whereas pneumococcal serotype diversity was lower in single-species OM than in single-species colonization, levels of serotype diversity did not differ significantly between colonization and OM in mixed-species episodes. Serotypes differed roughly 100-fold in progression rates, and those differences were attenuated in polymicrobial episodes. Vaccine serotype pneumococci had higher rates of progression than nonvaccine serotypes. While serotype invasiveness was a weak predictor of the OM progression rate, efficient capsular metabolic properties-traditionally thought to serve as an advantage in colonization-predicted an enhanced rate of progression to complex OM. The lower capacity of nonvaccine serotypes to cause OM may partially account for reductions in all-cause OM incidence despite serotype replacement in carriage following rollout of PCVs.

Effect of Antimicrobial Treatment on the Resolution of Middle-Ear Effusion After Acute Otitis Media.

BACKGROUND: Acute otitis media (AOM) induces middle-ear effusion (MEE), which affects hearing. The effect of antimicrobial treatment on the resolution of MEE is controversial, and the factors that affect resolution are unknown. METHODS: We studied the effect of antimicrobial treatment on the time to the resolution of MEE as a secondary objective in our randomized double-blind placebo-controlled trial. Children aged 6 to 35 months with stringently diagnosed AOM were allocated to receive amoxicillin-clavulanate (161 patients) or placebo (158 patients) for 7 days and closely followed for 3 months. This study was registered at ClinicalTrials.gov (identifier NCT00299455). RESULTS: The median times to resolution of MEE were 20 days (95% confidence interval [CI], 16-24 days) and 29 days (95% CI, 26-32 days) in the amoxicillin-clavulanate and placebo groups, respectively (P = .10). The resolution of MEE was confirmed in 138 (86%) of 161 and 132 (84%) of 158 patients in the amoxicillin-clavulanate and placebo groups, respectively (P = .59). In multivariable analysis, the resolution of MEE was prolonged most significantly by at least 1 recurrence of AOM during follow-up. MEE resolved in 65 (65%) of 100 patients with a recurrence of AOM during follow-up and in 205 (94%) of 219 of those without a recurrence (P < .001) (median times to resolution, 67 vs 15 days, respectively; P < .001). CONCLUSIONS: Immediate antimicrobial treatment of AOM does not significantly affect the resolution of MEE in young children. Subsequent recurrences of AOM are a major reason for the persistence of MEE.

Prognostic Factors for Treatment Failure in Acute Otitis Media.

BACKGROUND AND OBJECTIVES: Antimicrobial treatment is effective in the management of acute otitis media (AOM), but approximately half of the children may recover without antimicrobial agents. By identifying patients who may not require antimicrobial treatment for the management of AOM, the use of antimicrobial agents could be substantially reduced. Our aim was to identify subgroups of children with AOM who would benefit most from antimicrobial treatment and children who could be suitable for initial observation. METHODS: This is a secondary analysis of randomized, double-blind, placebo-controlled trial. Children 6 to 35 months of age with AOM (N = 319) were randomly allocated to receive amoxicillin-clavulanate (40/5.7 mg/kg per day) or placebo for 7 days. Our primary outcome was time until treatment failure. RESULTS: Treatment failure occurred in 31.7% of all children. Older age (24-35 months) and peaked tympanogram at entry decreased the hazard for treatment failure (hazard ratio, 0.53; 95% confidence interval [CI], 0.29 to 0.96; P = .04; and hazard ratio, 0.43; 95% CI, 0.21 to 0.88; P = .02, respectively). The rate difference for treatment failure between antimicrobial treatment and placebo groups was highest among children with severe bulging of the tympanic membrane (11.1% vs 64.1%; rate difference -53.0%; 95% CI, -73.5% to -32.4%), resulting in a number needed to treat of 1.9. CONCLUSIONS: Children with severe bulging of the tympanic membrane seem to benefit most from antimicrobial treatment of AOM. On the other hand, children with peaked tympanogram (A and C curves) may be optimal candidates for initial observation.