Vaccine
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New influenza vaccine formulations are designed to improve vaccine effectiveness and protect those most vulnerable to infection. High dose trivalent inactivated influenza vaccine (HD-IIV3), licensed for ages ≥65 years, produces greater antibody responses and efficacy in clinical trials, but post-licensure vaccine effectiveness (VE) compared to standard dose (SD-IIV3/4) vaccine remains an open question. ⋯ Among adults ≥65 years of age, recipients of standard and high dose influenza vaccines differed significantly in their characteristics. After adjusting for these differences, high dose vaccine offered more protection against A/H3N2 and borderline significant protection against all influenza A requiring outpatient care during the 2015-2018 influenza seasons.
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Maternal immunization has the potential to reduce both maternal and infant morbidity and mortality by protecting women from complications during pregnancy as well as conferring protection for babies who are too young to be vaccinated. Limited evidence is available about the drivers of maternal immunization in middle-income countries such as Peru. Vaccines against tetanus, diphtheria and influenza are recommended beginning in the second trimester in Peru; however, vaccination coverage has remained low in Peru compared to other countries in the region. As additional vaccines are recommended for administration in pregnancy, a better understanding of the perceptions and attitudes of pregnant women that influence vaccination are needed to design communication materials. ⋯ Overall, participants were supportive of maternal vaccination. They believed that vaccines were effective in protecting both their unborn baby and themselves. The main reason given for non-vaccination was lack of knowledge about vaccination in pregnancy. The strong desire expressed by study participants to get more information presents an opportunity for immunization programs to develop interventions that facilitate better information dissemination to pregnant women to increase vaccination uptake.
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Randomized Controlled Trial
Clinical trial to assess immunogenicity of high-dose, adjuvanted, and recombinant influenza vaccines against cell-grown A(H3N2) viruses in adults 65 to 74 years, 2017-2018.
Licensed inactivated influenza vaccines (IIV) are recommended for persons aged ≥65 years, including trivalent high-dose IIV (HD-IIV3) and adjuvanted IIV (aIIV3); both are manufactured in eggs. Quadrivalent recombinant vaccine (RIV4) is produced without eggs. We conducted an exploratory study to compare immunogenicity of HD-IIV3, aIIV3 and RIV4 against cell-grown vaccine and circulating A(H3N2) viruses in 2017-18. ⋯ High-dose, adjuvanted, and recombinant vaccines generated suboptimal neutralizing antibody responses to the cell-grown vaccine strain, but RIV4 generated a greater cross-protective response against circulating and antigenically advanced viruses. Recombinant technology may contribute to more broadly protective influenza vaccines, and comparative effectiveness studies are needed.
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COVID-19 pandemic has affected routine immunization globally. Impact will likely be higher in low and middle-income countries with limited healthcare resources and fragile health systems. We quantified the impact, spatial heterogeneity, and determinants for childhood immunizations of 48 million population affected in the Sindh province of Pakistan. ⋯ One out of every two children in Sindh province has missed their routine vaccinations during the provincial COVID-19 lockdown. The pool of un-immunized children is expanding during lockdown, leaving them susceptible to vaccine-preventable diseases. There is a need for tailored interventions to promote immunization visits and safe service delivery. Higher maternal education, facility-based births, and early enrollment into the immunization program continue to show a positive association with immunization uptake, even during a challenging lockdown.
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Declining vaccination coverage and increasing hesitancy is a worldwide concern. Many countries have implemented mandatory vaccination policies to promote vaccination. However, mandatory vaccination policies differ significantly by country. Beyond case studies, no comprehensive study has compared these policies or the penalties for non-compliance on a global scale. ⋯ We undertook a comprehensive assessment of national mandatory vaccination policies and identified a diversity of penalties in place to promote compliance. Our results highlight the need to critically evaluate the implementation of non-compliance penalties in order to determine their effectiveness and to define best practices for sustaining high vaccination uptake worldwide.