Effectiveness of Pfizer-BioNTech mRNA Vaccination Against COVID-19 Hospitalization Among Persons Aged 12-18 Years - United States, June-September 2021

COVID Vaccines in Adolescents and Young Adults

Worldwide, a number of COVID-19 vaccines have been approved or granted Emergency Use Authorization (EUA) or Emergency Use Listing for adolescents and young adults (AYA), which has brought hope to many across the globe. Extension of the EUA for a COVID-19 vaccine to children and adolescents aged 5 through 15 years is exciting news for children, adolescents, parents, and providers of AYA. Many countries around the globe have extended immunization against COVID-19 to younger age groups. At the same time, the COVID-19 pandemic has led to a decrease globally in administration of other adolescent vaccines. This highlights that vaccine recommendations do not necessarily lead to successful and equitable vaccine distribution, and overcoming barriers to vaccination is critical. Certain subpopulations of AYA, particularly those who are marginalized/underrepresented, do not receive appropriate health care. AYA should be offered protection against all vaccine-preventable illnesses at every opportunity. Creating innovative strategies to improve vaccine uptake among AYA should be encouraged.

Severe Acute Respiratory Syndrome Coronavirus 2 Infections in Children

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections in children generally have milder presentations, but severe disease can occur in all ages. MIS-C and persistent post-acute COVID-19 symptoms can be experienced by children with previous infection and emphasize the need for infection prevention. Optimal treatment for COVID-19 is not known, and clinical trials should include children to guide therapy. Vaccines are the best tool at preventing infection and severe outcomes of COVID-19. Children suffered disproportionately during the pandemic not only from SARS-CoV-2 infection but because of disruptions to daily life, access to primary care, and worsening income inequalities.

Cross-reactive immunity against the SARS-CoV-2 Omicron variant is low in pediatric patients with prior COVID-19 or MIS-C

Neutralization capacity of antibodies against Omicron after a prior SARS-CoV-2 infection in children and adolescents is not well studied. Therefore, we evaluated virus-neutralizing capacity against SARS-CoV-2 Alpha, Beta, Gamma, Delta and Omicron variants by age-stratified analyses (<5, 5-11, 12-21 years) in 177 pediatric patients hospitalized with severe acute COVID-19, acute MIS-C, and in convalescent samples of outpatients with mild COVID-19 during 2020 and early 2021. Across all patients, less than 10% show neutralizing antibody titers against Omicron. Children <5 years of age hospitalized with severe acute COVID-19 have lower neutralizing antibodies to SARS-CoV-2 variants compared with patients >5 years of age. As expected, convalescent pediatric COVID-19 and MIS-C cohorts demonstrate higher neutralization titers than hospitalized acute COVID-19 patients. Overall, children and adolescents show some loss of cross-neutralization against all variants, with the most pronounced loss against Omicron. In contrast to SARS-CoV-2 infection, children vaccinated twice demonstrated higher titers against Alpha, Beta, Gamma, Delta and Omicron. These findings can influence transmission, re-infection and the clinical disease outcome from emerging SARS-CoV-2 variants and supports the need for vaccination in children.

Real-Word Effectiveness of Global COVID-19 Vaccines Against SARS-CoV-2 Variants: A Systematic Review and Meta-Analysis

Background

Currently, promoted vaccinations against SARS-CoV-2 are being given out globally. However, the occurrence of numerous COVID-19 variants has hindered the goal of rapid mitigation of the COVID-19 pandemic by effective mass vaccinations. The real-word effectiveness of the current vaccines against COVID-19 variants has not been assessed by published reviews. Therefore, our study evaluated the overall effectiveness of current vaccines and the differences between the various vaccines and variants.

Methods

PubMed, Embase, Cochrane Library, medRxiv, bioRxiv, and arXiv were searched to screen the eligible studies. The Newcastle-Ottawa scale and the Egger test were applied to estimate the quality of the literature and any publication bias, respectively. The pooled incident rates of different variants after vaccination were estimated by single-arm analysis. Meanwhile, the pooled efficacies of various vaccines against variants were evaluated by two-arm analysis using odds ratios (ORs) and vaccine effectiveness (VE).

Results

A total of 6,118 studies were identified initially and 44 articles were included. We found that the overall incidence of variants post first/second vaccine were 0.07 and 0.03, respectively. The VE of the incidence of variants post first vaccine between the vaccine and the placebo or unvaccinated population was 40% and post second vaccine was 96%, respectively. The sub-single-arm analysis showed a low prevalence rate of COVID-19 variants after specific vaccination with the pooled incidence below 0.10 in most subgroups. Meanwhile, the sub-two-arm analysis indicated that most current vaccines had a good or moderate preventive effect on certain variants considering that the VE in these subgroups was between 66 and 95%, which was broadly in line with the results of the sub-single-arm analysis.

Conclusion

Our meta-analysis shows that the current vaccines that are used globally could prevent COVID-19 infection and restrict the spread of variants to a great extent. We would also support maximizing vaccine uptake with two doses, as the effectiveness of which was more marked compared with one dose. Although the mRNA vaccine was the most effective against variants according to our study, specific vaccines should be taken into account based on the local dominant prevalence of variants.

BNT162b2 Protection against the Omicron Variant in Children and Adolescents

BACKGROUND

Spread of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) B.1.1.529 (omicron) variant, which led to increased U.S. hospitalizations for coronavirus disease 2019 (Covid-19), generated concern about immune evasion and the duration of protection from vaccines in children and adolescents.

METHODS

Using a case-control, test-negative design, we assessed vaccine effectiveness against laboratory-confirmed Covid-19 leading to hospitalization and against critical Covid-19 (i.e., leading to receipt of life support or to death). From July 1, 2021, to February 17, 2022, we enrolled case patients with Covid-19 and controls without Covid-19 at 31 hospitals in 23 states. We estimated vaccine effectiveness by comparing the odds of antecedent full vaccination (two doses of BNT162b2 messenger RNA vaccine) at least 14 days before illness among case patients and controls, according to time since vaccination for patients 12 to 18 years of age and in periods coinciding with circulation of B.1.617.2 (delta) (July 1, 2021, to December 18, 2021) and omicron (December 19, 2021, to February 17, 2022) among patients 5 to 11 and 12 to 18 years of age.

RESULTS

We enrolled 1185 case patients (1043 [88%] of whom were unvaccinated, 291 [25%] of whom received life support, and 14 of whom died) and 1627 controls. During the delta-predominant period, vaccine effectiveness against hospitalization for Covid-19 among adolescents 12 to 18 years of age was 93% (95% confidence interval [CI], 89 to 95) 2 to 22 weeks after vaccination and was 92% (95% CI, 80 to 97) at 23 to 44 weeks. Among adolescents 12 to 18 years of age (median interval since vaccination, 162 days) during the omicron-predominant period, vaccine effectiveness was 40% (95% CI, 9 to 60) against hospitalization for Covid-19, 79% (95% CI, 51 to 91) against critical Covid-19, and 20% (95% CI, -25 to 49) against noncritical Covid-19. During the omicron period, vaccine effectiveness against hospitalization among children 5 to 11 years of age was 68% (95% CI, 42 to 82; median interval since vaccination, 34 days).

CONCLUSIONS

BNT162b2 vaccination reduced the risk of omicron-associated hospitalization by two thirds among children 5 to 11 years of age. Although two doses provided lower protection against omicron-associated hospitalization than against delta-associated hospitalization among adolescents 12 to 18 years of age, vaccination prevented critical illness caused by either variant. (Funded by the Centers for Disease Control and Prevention.).

Safety and Immunogenicity of the BBIBP-CorV Vaccine in Adolescents Aged 12 to 17 Years in the Thai Population: An Immunobridging Study

Adolescents can develop a severe form of Coronavirus disease 2019 (COVID-19), especially with underlying comorbidities. No study has examined the efficacy or effectiveness of inactivated COVID-19 vaccines in adolescents. This single-center, prospective cohort study was performed to evaluate the safety and effectiveness of an inactivated COVID-19 vaccine in adolescents using the immunobridging approach at Chulabhorn Hospital. The key eligibility criterion was a healthy clinical condition or stable pre-existing comorbidity. The anti-receptor-binding domain (anti-RBD) antibody concentration at 4 weeks after dose 2 of the vaccine was compared between participants aged 12 to 17 years and those aged 18 to 30 years. Safety profiles included adverse events within 7 days after each dose of the vaccine and any adverse events through 1 month after dose 2 of the vaccine. In the adolescent and adult cohorts, the geometric mean concentration of anti-RBD antibody was 102.9 binding antibody unit (BAU)/mL (95% CI, 91.0−116.4) and 36.9 BAU/mL (95% CI, 30.9−44.0), respectively. The geometric mean ratio of the adolescent cohort was 2.79 (95% CI, 2.25−3.46, p < 0.0001) compared with the adult cohort, meeting the non-inferiority criterion. The reactogenicity was slightly lower in the adolescent than in the adult cohort. No serious adverse events occurred. The inactivated COVID-19 vaccine appears safe and effective in adolescents.

BNT162b2 Vaccine-Associated Myo/Pericarditis in Adolescents: A Stratified Risk-Benefit Analysis

BACKGROUND

Male patients ages 12-17 years have an elevated risk of mRNA vaccination-associated myo/pericarditis. A risk-benefit analysis of first and second doses of mRNA vaccination in adolescent boys by health status and history of SARS-CoV-2 infection has not been performed.

METHODS

Using the Vaccine Adverse Event Reporting System (VAERS), we identified BNT162b2 [Pfizer-BioNTech] myo/pericarditis occurrence according to CDC criteria. Main outcomes were as follows: 1) post-vaccination myo/pericarditis crude incidence in adolescents aged 12-15 and 16-17; and 2) two risk-benefit analyses by age, sex, comorbidity, variant and history of infection.

RESULTS

Cases of myo/pericarditis (n = 253) included 129 after dose 1 and 124 after dose 2; 86.9% were hospitalized. Incidence per million after dose two in male patients aged 12-15 and 16-17 was 162.2 and 93.0, respectively. Weighing post-vaccination myo/pericarditis against COVID-19 hospitalization during delta, our risk-benefit analysis suggests that among 12-17-year-olds, two-dose vaccination was uniformly favourable only in nonimmune girls with a comorbidity. In boys with prior infection and no comorbidities, even one dose carried more risk than benefit according to international estimates. In the setting of omicron, one dose may be protective in nonimmune children, but dose two does not appear to confer additional benefit at a population level.

CONCLUSIONS

Our findings strongly support individualized paediatric COVID-19 vaccination strategies which weigh protection against severe disease vs. risks of vaccine-associated myo/pericarditis. Research is needed into the nature and implications of this adverse effect as well as immunization strategies which reduce harms in this overall low-risk cohort.

The Role of COVID-19 Vaccinal Status in Admitted Children during OMICRON Variant Circulation in Rio de Janeiro, City-Preliminary Report

Objective: To evaluate COVID-19 vaccination status in admitted children in 2020−2021 and during the OMICRON variant circulation (2022), a period when children older than 12 years of age had received two doses of COVID-19 vaccines. Design: An observational retrospective study. Patients with confirmed COVID-19 were compared in two different periods: 2020−2021 when adolescents aged 12−18 years had not received the complete COVID-19 vaccine, and 2022 when children older than 12 years had received the complete Pfizer-BioNTech vaccine scheme. Setting: Two pediatric hospitals in Rio de Janeiro city. Patients: Children aged < 18 years with confirmed COVID-19. Intervention: None. Main outcome: Vaccination status for COVID-19 on admission. Results: In total, 300 patients were admitted with confirmed COVID-19 (240 in 2020−2021 and 60 in 2022). The distribution of patients according to the age-groups was: 0−2 years (33.3% in 2020−2021 and 53.4% in 2022), 2−5 years (21.7% in 2020−2021 and 10% in 2022), 5−11 years (29.2% in 2020−2021 and 28.3% in 2022), and 12−18 years (15.8% in 2020−2021 and 8.3% in 2022) (p = 0.076). The median length of stay was six days in 2020−2021 and six days in 2022 (p = 0.423). We verified six deaths in the first analysis period and one death in the second one (p = 0.894). Of the 60 children admitted in 2022, 58 (96.7%) did not receive the complete COVID-19 vaccine scheme available. Conclusions: We verified in a “real-world condition” the ability of the Pfizer-BioNTech vaccine to prevent hospitalization in children over 12 years of age.

Association Between Risk Perception and Acceptance for a Booster Dose of COVID-19 Vaccine to Children Among Child Caregivers in China

Background

At present, the widespread variants and the weakened immunity provided by vaccines over time have further emphasized the importance of vaccination, boosters, and prevention efforts against COVID-19. Here, this study intends to investigate the acceptability of a booster dose of COVID-19 vaccine among child caregivers, aiming to explore the association between risk perception and child vaccine acceptance.

Methods

This anonymous, national, cross-sectional survey was conducted for one week from November 12, 2021 in mainland China. The risk perception among child caregivers was assessed based on the Health Belief Model (HBM) and the individuals was equally divided into three levels according to the total preset scores of each perception dimension. Pearson χ² test was used to compare the differences among participants stratified by sociodemographic characteristics, health status, knowledge factors and risk perception. Univariate and multivariate logistic regression models were performed to explore the associations between risk perception and the acceptance of a booster dose of COVID-19 vaccine.

Results

A total of 88.46% of 1,724 participants were willing to accept the booster dose of the COVID-19 vaccine for their children. People who lived in central China (91.93%), had a high school or polytechnic school level education (93.98%), and had a history of COVID-19 vaccination (88.80%) were more likely to accept a booster dose of the COVID-19 vaccine for their children. The complicated vaccination process (24.5%) and uncertainty about the safety (16.5%) and efficacy (21.3%) of vaccines were the three main reasons for vaccine hesitancy among child caregivers. The acceptance of the booster dose of the COVID-19 vaccine was closely related to a higher level of perceived susceptibility (moderate: aOR = 1.56, 95% CI: 1.07–2.29, P = 0.022; high: aOR = 1.75, 95% CI: 1.06–2.89, P = 0.029) and high perceived benefit (high: aOR = 7.22, 95% CI: 2.63–19.79, P < 0.001). The results were stable in the sensitivity analysis.

Conclusions

88.46% of child caregivers were willing to have a booster dose of COVID-19 vaccine to children, and the acceptance was closely associated with a higher level of perceived susceptibility and perceived benefit. The complicated vaccination process, uncertainty about the safety and effectiveness of COVID-19 vaccines were the main reasons for their hesitancy. Therefore, targeted public health measures to increase perceived susceptibility and benefit are still needed to meet the requirements of higher-level immunization coverage.

Parental COVID-19 Vaccine Hesitancy for Children in Romania: National Survey

PURPOSE

Once vaccination against COVID-19 was also possible for children over 12 years of age, parents/legal guardians had to give their consent for their vaccination. It is a crucial moment, given the large number of infected people in Romania and the fact that these children are a source of transmission of the virus in the community. The refusal or hesitation of the parents/legal guardians, regarding the agreement for the vaccination of the children, determined us to focus on this subject, wishing, based on the questioning of as many parents as possible, to extract the reasons underlying these decisions.

METHODS

This study is designed to observe the attitudes of parents/legal guardians regarding the refusal, hesitation, or acceptance of vaccination of children. The persons targeted to answer the questionnaire had to meet three conditions: to be at least 21 years old, to have a stable residence in Romania, and to be parents/legal guardians of at least one child under 18 years of age. The questionnaire was applied online to a number of 581 parents/legal guardians, being structured to obtain socio-demographic data and other categories of data that allow us to analyze their views on vaccinating children.

RESULTS

Sociological data resulting from the application of the questionnaire on 581 parents/legal guardians show that 183 (31.5%) adults and 140 (24.1%) children got infected with COVID-19. The total number of respondents shows that only 411 (70.7%) adults and 185 (31.8%) children are vaccinated.

CONCLUSIONS

From the analysis of the data obtained through the questionnaire, following the application of the Kendall and Spearman statistical analysis tests, it is found that there is a strong link between participants' trust/distrust in "fake news" information and their decision to vaccinate their children.

Effectiveness of mRNA-1273, BNT162b2, and JNJ-78436735 COVID-19 Vaccines Among US Military Personnel Before and During the Predominance of the Delta Variant

Importance

No studies to date have evaluated the effectiveness of 3 COVID-19 vaccines in the US military population, especially during the circulation of the SARS-CoV-2 Delta (B.1.617.2) variant.

Objective

To estimate the effectiveness of the mRNA-1273, BNT162b2, and JNJ-78436735 vaccines among US military personnel before and during the predominance of the Delta variant in the US.

Design, Setting, and Participants

This case-control study was conducted among all unvaccinated and fully vaccinated US military personnel who had a documented SARS-CoV-2 test performed in the US between January 1 and September 24, 2021. Individuals were identified using Department of Defense (DOD) electronic medical, laboratory, and surveillance databases. The pre-Delta period was defined as January 1 to May 31, 2021, and the Delta period as June 19 to September 24, 2021. Case individuals were defined by a positive polymerase chain reaction SARS-CoV-2 test result or a positive antigen test result with symptoms. Control individuals had at least 1 negative SARS-CoV-2 test result.

Exposures

COVID-19 vaccination with the mRNA-1273, BNT162b2, or JNJ-78436735 vaccine, assessed from DOD electronic vaccination records.

Main Outcomes and Measures

COVID-19 vaccine effectiveness overall, by vaccine type, and by outcome stratified by the pre-Delta and Delta periods in the US. Vaccine effectiveness was estimated as 100 × (1 - odds ratio) in a logistic regression model with adjustment for potential confounders.

Results

The cohort included 441 379 individuals, with 290 256 in the pre-Delta period (236 555 [81%] male; median age, 25 years [range, 17-68 years]) and 151 123 in the Delta period (120 536 [80%] male; median age, 26 years [range, 17-70 years]). Adjusted vaccine effectiveness of all vaccines was significantly higher during the pre-Delta period (89.2%; 95% CI, 88.1%-90.1%) compared with the Delta period (70.2%; 95% CI, 69.3%-71.1%) for all outcomes, an overall decrease of 19%. mRNA-1273 vaccine effectiveness was highest in the pre-Delta (93.5%; 95% CI, 91.9%-94.7%) and Delta (79.4%; 95% CI, 78.3%-80.4%) periods for all outcomes, whereas the JNJ-78436735 vaccine had the lowest effectiveness during the pre-Delta (81.8%; 95% CI, 74.2%- 87.1%) and Delta (38.3%; 95% CI, 34.5%-41.9%) periods. Effectiveness for all vaccines during both periods was higher for symptomatic infection and hospitalization among individuals with SARS-CoV-2 infection.

Conclusions and Relevance

In this case-control study, among US military personnel, COVID-19 vaccine effectiveness was significantly lower during the period when the Delta variant predominated compared with the period before Delta variant predominance; this was especially true for the JNJ-78436735 vaccine. These findings were confounded by time since vaccination; this and the change in effectiveness support the need for booster doses and continued evaluation of vaccine effectiveness as new variants of SARS-CoV-2 emerge.

Messenger ribonucleic acid vaccines for severe acute respiratory syndrome coronavirus-2 - a review

The mRNA therapeutics have been studied since the 1970s and the currently available mRNA vaccines against COVID-19 are the culmination of decades of scientific research. The mRNA vaccines BNT162b2 and mRNA-1273 have played a key role in our global response to the COVID-19 pandemic as they have demonstrated significant advantages over conventional vaccines and have proven to be highly effective against COVID-19 associated hospitalization and severe illness in large clinical trials and studies using real-world data.

Effectiveness of BNT162b2 and mRNA-1273 Vaccines against COVID-19 Infection: A Meta-Analysis of Test-Negative Design Studies

Although numerous COVID-19 vaccines are effective against COVID-19 infection and variants of concern (VOC) in the real world, it is imperative to obtain evidence of the corresponding vaccine effectiveness (VE). This study estimates the real-world effectiveness of the BNT162b2 and mRNA-1273 vaccines against COVID-19 infection and determines the influence of different virus variants on VE by using test-negative design (TND) studies. We systematically searched for published articles on the efficacy of BNT162b2 and mRNA-1273 against COVID-19 infection. Two researchers independently selected and extracted data from eligible studies. We calculated the VE associated with different vaccine types, SARS-CoV-2 variants, and vaccination statuses, using an inverse variance random-effects model. We selected 19 eligible studies in the meta-analysis from 1651 records. For the partially vaccinated group, the VE of BNT162b2 and mRNA-1273 was 61% and 78% against COVID-19 infection, respectively. For the completely vaccinated group, the VE of BNT162b2 and mRNA-1273 was 90% and 92% against COVID-19 infection, respectively. During subgroup analyses, the overall VE of BNT162b2 and mRNA-1273 against the Delta variant was 53% and 71%, respectively, for the partially vaccinated group; the respective VE values were 85% and 91% for the fully vaccinated group. Irrespective of the BNT162b2 or mRNA-1273 vaccines, the Delta variant significantly weakened vaccine protection for the partially vaccinated group, while full vaccination was highly effective against COVID-19 infection and various VOC. The mRNA-1273 vaccine is more effective against COVID-19 infection and VOC than the BNT162b2 vaccine, especially for the partially vaccinated group. Overall, the results provide recommendations for national and regional vaccine policies.

Effectiveness and Safety of SARS-CoV-2 Vaccines among Children and Adolescents: A Systematic Review and Meta-Analysis

Background: The proportion of children and adolescents with COVID-19 had gradually increased according to data reported by WHO. However, there was no meta-analysis of effectiveness and safety of SARS-CoV-2 vaccines in children and adolescents. We aimed to provide investigation-based medical evidence and reference recommendations for children and adolescents in regard to SARS-CoV-2 vaccines. Methods: We systematically searched PubMed, Embase, and Web of Science from inception to 5 January 2022. RCTs and observational studies that examined the effectiveness and safety were included. Results: A total of 13 eligible studies were included for analysis. For the first dose, the effectiveness of SARS-CoV-2 vaccines against SARS-CoV-2 infection and COVID-19 was 88.5% (95% CI:15.7−98.4%, p = 0.033) and 84.3% (95% CI: 66.6−92.6%, p < 0.001) separately. For the second dose, the effectiveness against SARS-CoV-2 infection and COVID-19 was 91.6% (95% CI: 37.8−99.5%, p = 0.083) and 92.7 (95% CI: 82.2−97.0, p < 0.001) separately. Injection-site pain, fatigue, headache, anorexia, and axillary swelling were the top five adverse events after the first dose of SARS-CoV-2 vaccines. Fatigue, injection-site pain, headache, chills, and myalgia/muscle pain were the top five adverse events after the second dose of SARS-CoV-2 vaccines. Conclusions: SARS-CoV-2 vaccines had good effectiveness and safety in children and adolescents. We suggest that children and adolescents should get vaccinated as soon as possible to protect themselves and slow the spread of the pandemic.

Effectiveness of BNT162b2 Vaccine against Critical Covid-19 in Adolescents

BACKGROUND

The increasing incidence of pediatric hospitalizations associated with coronavirus disease 2019 (Covid-19) caused by the B.1.617.2 (delta) variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the United States has offered an opportunity to assess the real-world effectiveness of the BNT162b2 messenger RNA vaccine in adolescents between 12 and 18 years of age.

METHODS

We used a case-control, test-negative design to assess vaccine effectiveness against Covid-19 resulting in hospitalization, admission to an intensive care unit (ICU), the use of life-supporting interventions (mechanical ventilation, vasopressors, and extracorporeal membrane oxygenation), or death. Between July 1 and October 25, 2021, we screened admission logs for eligible case patients with laboratory-confirmed Covid-19 at 31 hospitals in 23 states. We estimated vaccine effectiveness by comparing the odds of antecedent full vaccination (two doses of BNT162b2) in case patients as compared with two hospital-based control groups: patients who had Covid-19-like symptoms but negative results on testing for SARS-CoV-2 (test-negative) and patients who did not have Covid-19-like symptoms (syndrome-negative).

RESULTS

A total of 445 case patients and 777 controls were enrolled. Overall, 17 case patients (4%) and 282 controls (36%) had been fully vaccinated. Of the case patients, 180 (40%) were admitted to the ICU, and 127 (29%) required life support; only 2 patients in the ICU had been fully vaccinated. The overall effectiveness of the BNT162b2 vaccine against hospitalization for Covid-19 was 94% (95% confidence interval [CI], 90 to 96); the effectiveness was 95% (95% CI, 91 to 97) among test-negative controls and 94% (95% CI, 89 to 96) among syndrome-negative controls. The effectiveness was 98% against ICU admission and 98% against Covid-19 resulting in the receipt of life support. All 7 deaths occurred in patients who were unvaccinated.

CONCLUSIONS

Among hospitalized adolescent patients, two doses of the BNT162b2 vaccine were highly effective against Covid-19-related hospitalization and ICU admission or the receipt of life support. (Funded by the Centers for Disease Control and Prevention.).

Safety and effectiveness of BNT162b2 mRNA Covid-19 vaccine in adolescents

In South Korea, all 12th grade students (highs school seniors) were offered BNT162b2 vaccine starting July 19, 2021; while 10^th-11th grade students were not eligible. We conducted a nationwide retrospective cohort study by to determine the safety and effectiveness of BNT162b2 mRNA Covid-19 vaccine in adolescents against SARS-CoV-2 infection. Among 444,313 persons who received the first dose of vaccine, reporting rate for myocarditis and/or pericarditis was 1.8 per 100,000 (95% C.I. 0.8-3.5) among first-dose recipients and 4.3 per 100,000 (95% C.I. 2.6-6.7) in second-dose recipients. Vaccine effectiveness against symptomatic/asymptomatic SARS-CoV-2 infection 14 days post-first dose vaccination was 91.1% (95% C.I. 89.6-92.5), and 14 days post-second dose was 99.1% (95% C.I. 98.5-99.5). In this retrospective cohort study, BNT162b2 vaccination was safe and was associated with a significantly lower risk of SARS-CoV-2 infection, suggesting that vaccination in adolescent may reduce the burden of Covid-19.

Effectiveness of BNT162b2 (Pfizer-BioNTech) mRNA Vaccination Against Multisystem Inflammatory Syndrome in Children Among Persons Aged 12-18 Years - United States, July-December 2021

Multisystem inflammatory syndrome in children (MIS-C) is a severe postinfectious hyperinflammatory condition, which generally occurs 2-6 weeks after a typically mild or asymptomatic infection with SARS-CoV-2, the virus that causes COVID-19 (1-3). In the United States, the BNT162b2 (Pfizer-BioNTech) COVID-19 vaccine is currently authorized for use in children and adolescents aged 5-15 years under an Emergency Use Authorization and is fully licensed by the Food and Drug Administration for persons aged ≥16 years (4). Prelicensure randomized trials in persons aged ≥5 years documented high vaccine efficacy and immunogenicity (5),§ and real-world studies in persons aged 12-18 years demonstrated high vaccine effectiveness (VE) against severe COVID-19 (6). Recent evidence suggests that COVID-19 vaccination is associated with lower MIS-C incidence among adolescents (7); however, VE of the 2-dose Pfizer-BioNTech regimen against MIS-C has not been evaluated. The effectiveness of 2 doses of Pfizer-BioNTech vaccine received ≥28 days before hospital admission in preventing MIS-C was assessed using a test-negative case-control design¶ among hospitalized patients aged 12-18 years at 24 pediatric hospitals in 20 states** during July 1-December 9, 2021, the period when most MIS-C patients could be temporally linked to SARS-CoV-2 B.1.617.2 (Delta) variant predominance. Patients with MIS-C (case-patients) and two groups of hospitalized controls matched to case-patients were evaluated: test-negative controls had at least one COVID-19-like symptom and negative SARS-CoV-2 reverse transcription-polymerase chain reaction (RT-PCR) or antigen-based assay results, and syndrome-negative controls were hospitalized patients without COVID-19-like illness. Among 102 MIS-C case-patients and 181 hospitalized controls, estimated effectiveness of 2 doses of Pfizer-BioNTech vaccine against MIS-C was 91% (95% CI = 78%-97%). All 38 MIS-C patients requiring life support were unvaccinated. Receipt of 2 doses of the Pfizer-BioNTech vaccine is associated with a high level of protection against MIS-C in persons aged 12-18 years, highlighting the importance of vaccination among all eligible children.

The Burden of COVID-19 in Children and Its Prevention by Vaccination: A Joint Statement of the Israeli Pediatric Association and the Israeli Society for Pediatric Infectious Diseases

As of October 2021, SARS-CoV-2 infections were reported among 512,613 children and adolescents in Israel (~33% of all COVID-19 cases). The 5-11-year age group accounted for about 43% (223,850) of affected children and adolescents. In light of the availability of the Pfizer-BioNTech BNT162b2 vaccine against COVID-19 for children aged 5-11 years, we aimed to write a position paper for pediatricians, policymakers and families regarding the clinical aspects of COVID-19 and the vaccination of children against COVID-19. The first objective of this review was to describe the diverse facets of the burden of COVID-19 in children, including the direct effects of hospitalization during the acute phase of the disease, multisystem inflammatory syndrome in children, long COVID and the indirect effects of social isolation and interruption in education. In addition, we aimed to provide an update regarding the efficacy and safety of childhood mRNA COVID-19 vaccination and to instill confidence in pediatricians regarding the benefits of vaccinating children against COVID-19. We reviewed up-to-date Israeli and international epidemiological data and literature regarding COVID-19 morbidity and its sequelae in children, vaccine efficacy in reducing COVID-19-related morbidity and SARS-CoV-2 transmission and vaccine safety data. We conducted a risk-benefit analysis regarding the vaccination of children and adolescents. We concluded that vaccines are safe and effective and are recommended for all children aged 5 to 11 years to protect them from COVID-19 and its complications and to reduce community transmissions. Based on these data, after weighing the benefits of vaccination versus the harm, the Israeli Ministry of Health decided to recommend vaccination for children aged 5-11 years.

Considerations for the Safe Operation of Schools During the Coronavirus Pandemic

During the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, providing safe in-person schooling has been a dynamic process balancing evolving community disease burden, scientific information, and local regulatory requirements with the mandate for education. Considerations include the health risks of SARS-CoV-2 infection and its post-acute sequelae, the impact of remote learning or periods of quarantine on education and well-being of children, and the contribution of schools to viral circulation in the community. The risk for infections that may occur within schools is related to the incidence of SARS-CoV-2 infections within the local community. Thus, persistent suppression of viral circulation in the community through effective public health measures including vaccination is critical to in-person schooling. Evidence suggests that the likelihood of transmission of SARS-CoV-2 within schools can be minimized if mitigation strategies are rationally combined. This article reviews evidence-based approaches and practices for the continual operation of in-person schooling.