A randomized trial assessing the efficacy, immunogenicity, and safety of vaccination with live attenuated varicella zoster virus-containing vaccines: ten-year follow-up in Russian children.

In Russia, a universal varicella vaccination (UVV) program has not been implemented, and varicella vaccination coverage is low. We assessed the efficacy, antibody persistence, and safety of one- and two-dose varicella vaccination schedules in Russian children with a ten-year follow-up period, as part of an international phase IIIB, observer-blind, randomized, controlled trial (NCT00226499). Children aged 12-22 months were randomized (3:3:1) to receive two doses of tetravalent measles-mumps-rubella-varicella vaccine (V2 group), one dose trivalent measles-mumps-rubella (MMR) vaccine and one dose of varicella vaccine (V1 group), or two doses of MMR vaccine (V0 [control] group), 42 days apart. Main study outcomes were: vaccine efficacy (VE) against confirmed varicella cases, anti-varicella zoster virus (VZV) seropositivity rates and geometric mean concentrations, and reporting of (serious) adverse events ([S]AEs). The total vaccinated cohort in Russia comprised 1000 children; 900 were followed up until study end (year [Y] 10). VE estimates against confirmed varicella (Y10) were 92.4% in the V2 group and 74.7% in the V1 group. Anti-VZV seropositivity rates remained ≥99.4% in the V2 group and ≥89.7% in the V1 group from day 42 post-vaccination 2 until Y10. Occurrence of (un)solicited AEs and SAEs was similar across groups and confirmed the safety profile of the vaccines. No vaccination-related SAEs or deaths were reported. These results are consistent with the global trial results, i.e., the highest VE estimates observed following the two-dose schedule compared to the one-dose schedule. These data may inform decision-making related to potential implementation of a UVV program.

What is the context?Varicella is a common childhood disease caused by the highly contagious varicella zoster virus.Varicella vaccines have been used for more than three decades.A large clinical trial conducted in ten countries assessed the efficacy and safety of one dose of monovalent varicella vaccine or two doses of combined varicella vaccine (MMRV). The enrolled children were also followed up for a ten-year period to evaluate the persistence of the immune response and the long-term efficacy of the vaccine.What is new?Here, we present the long-term efficacy, immunogenicity, and safety results in the cohort of children enrolled in Russia, as part of the global ten-year follow-up study. We found that:The monovalent and combined vaccines reduced the number of varicella cases.The MMRV two-dose regimen displayed higher efficacy in preventing varicella of all severities compared to the one-dose regimen.The immune response conferred by the vaccine persisted up to ten years post-vaccination.No vaccination-related deaths occurred, and no safety concerns were raised.What is the impact?Vaccination against varicella resulted in long-term protective efficacy and antibody persistence over ten years post-vaccination in Russian children.Although one-dose varicella vaccination was effective at protecting against varicella, a two-dose schedule provided a more complete protection. This could inform health policy decisions regarding the implementation of varicella vaccination in routine immunization program in Russia.

Childhood asthma outcomes during the COVID-19 pandemic: Findings from the PeARL multi-national cohort.

BACKGROUND: The interplay between COVID-19 pandemic and asthma in children is still unclear. We evaluated the impact of COVID-19 pandemic on childhood asthma outcomes. METHODS: The PeARL multinational cohort included 1,054 children with asthma and 505 non-asthmatic children aged between 4 and 18 years from 25 pediatric departments, from 15 countries globally. We compared the frequency of acute respiratory and febrile presentations during the first wave of the COVID-19 pandemic between groups and with data available from the previous year. In children with asthma, we also compared current and historical disease control. RESULTS: During the pandemic, children with asthma experienced fewer upper respiratory tract infections, episodes of pyrexia, emergency visits, hospital admissions, asthma attacks, and hospitalizations due to asthma, in comparison with the preceding year. Sixty-six percent of asthmatic children had improved asthma control while in 33% the improvement exceeded the minimal clinically important difference. Pre-bronchodilatation FEV1 and peak expiratory flow rate were improved during the pandemic. When compared to non-asthmatic controls, children with asthma were not at increased risk of LRTIs, episodes of pyrexia, emergency visits, or hospitalizations during the pandemic. However, an increased risk of URTIs emerged. CONCLUSION: Childhood asthma outcomes, including control, were improved during the first wave of the COVID-19 pandemic, probably because of reduced exposure to asthma triggers and increased treatment adherence. The decreased frequency of acute episodes does not support the notion that childhood asthma may be a risk factor for COVID-19. Furthermore, the potential for improving childhood asthma outcomes through environmental control becomes apparent.

Effects of Smoking on the Prevalence of Allergic Disorders in Russian Adolescents: A Retrospective Cross-sectional Study.

Introduction Smoking is one of the leading causes of death. Smoking also decreases lung efficiency and impairs lung function in children of all ages. Second-hand tobacco smoking increases both the frequency and severity of childhood asthma. However, the role of active tobacco smoking in the manifestation of asthma remains inconclusive. The aim of this article was to describe the current understanding of the prevalence and adverse effects of cigarette smoking and to determine whether there is an association between smoking and the manifestation and progression of asthma among adolescents and high school students in Russia. Objectives This study aimed to determine the true prevalence of bronchial asthma (BA), allergic rhinitis (AR), and atopic dermatitis (AD) in the population of adolescents in the Russian Federation. In the GA2LEN (Global Allergy and Asthma European Network) study, we analyzed participant responses to confirm a connection between smoking and asthma exacerbation or development. This study examined the association between parental smoking and childhood atopic disorders. We sought to determine the effects of exposure to environmental tobacco smoke and childhood cigarette smoking on asthma symptoms among high school and college students in Moscow, Russia. We analyzed the reactions to the present tobacco control policy and evaluated the significance of the success of the policy. A number of methods were used, including questionnaires, surveys, and statistical analysis software. Results Our research indicates a moderate decrease in smoking prevalence among Russian teenagers. From the data and results of our study, 25.3% of the respondents said that they have ever smoked for as long as a year. Among the participants who had ever smoked, most of them started smoking at the age of 16 years while the state-reported average age for a new smoker is 11.4. Fifty percent of the respondents who had shortness of breath had been woken by an attack once a week in the last three months. Only 21.1% of the people with asthma were taking medicines for it. According to our calculations, there is no significant association between smoking status and the prevalence of asthma, hay fever, and sinusitis. More respondents (34.2%) had fathers who regularly smoked during their childhood than mothers who regularly smoked during their childhood or before the children were born (7.9%). There is a statistically significant association between a mother smoking during childhood or before the birth of a child and that child being hospitalized before the age of two years for lung disease. Conclusion The fact that the smoking rates among study participants are relatively low is quite encouraging and anti-smoking campaigns should be intensified to drive the rates lower. The data analyzed do not provide sufficient evidence to show that there is any causative association between smoking status and the development of asthma, hay fever, or sinusitis. Since there is no clear association between smoking status and the development of asthma, hay fever, or allergic sinusitis, it is imperative to say that smoking cessation will have very little effect on allergy prevalence as per the data analyzed. From the conducted analysis, it is evident that there is a clear link between second-hand smoke and asthma in children. According to our results, children whose mothers smoked are especially vulnerable to asthma and other respiratory disorders.