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    Abstract:
    Background Facilitated by the inability to vaccinate, and an immature immune system, COVID-19 remains a leading cause of death among children. Vaccinated lactating mothers produce specific SARS-CoV-2 antibodies in their milk, capable of neutralizing the virus in vitro . Our objective for this study is to assess the effect of COVID-19 booster dose on SARS-CoV-2 antibody concentration and viral neutralization in milk, plasma, and infant stool. Methods Thirty-nine mothers and 25 infants were enrolled from December 2020 to May 2022. Milk, maternal plasma, and infants' stool were collected at various time-points up to 12 months following mRNA COVID-19 vaccination. A subgroup of 14 mothers received a booster dose. SARS-CoV-2 antibody levels and their neutralization capacities were assessed. Results Booster vaccination led to significantly higher IgG levels within human milk and breastfed infants' stool. In vitro neutralization of VSV-gfp-SARS-CoV-2-S-gp, a laboratory safe SARS-CoV-2 like pseudovirus, improved following the booster, with a 90% increase in plasma neutralization and a 60% increase in milk neutralization. We found that post-booster neutralization by human milk was highly correlated to SARS-CoV-2 IgG level. In support of our correlation result, Protein G column depletion of IgG in milk yielded a significant reduction in viral neutralization ( p = 0.04). Discussion The substantial increase in neutralizing IgG levels in milk and breastfed infants' stool post-booster, coupled with the decrease in milk neutralization capabilities upon IgG depletion, underscores the efficacy of booster doses in augmenting the immune response against SARS-CoV-2 in human milk.
    Keywords:
    Booster (rocketry)
    Booster dose
    Booster (rocketry)
    Booster dose
    Inactivated Poliovirus Vaccine
    Polio vaccine
    Abstract While there are various attempts to administer COVID-19-convalescent plasmas to SARS-CoV-2-infected patients, neither appropriate approach nor clinical utility has been established. We examined the presence and temporal changes of the neutralizing activity of IgG fractions from 43 COVID-19-convalescent plasmas using cell-based assays with multiple endpoints. IgG fractions from 27 cases (62.8%) had significant neutralizing activity and moderately to potently inhibited SARS-CoV-2 infection in cell-based assays; however, no detectable neutralizing activity was found in 16 cases (37.2%). Approximately half of the patients (~ 41%), who had significant neutralizing activity, lost the neutralization activity within ~ 1 month. Despite the rapid decline of neutralizing activity in plasmas, good amounts of SARS-CoV-2-S1-binding antibodies were persistently seen. The longer exposure of COVID-19 patients to greater amounts of SARS-CoV-2 elicits potent immune response to SARS-CoV-2, producing greater neutralization activity and SARS-CoV-2-S1-binding antibody amounts. The dilution of highly-neutralizing plasmas with poorly-neutralizing plasmas relatively readily reduced neutralizing activity. The presence of good amounts of SARS-CoV-2-S1-binding antibodies does not serve as a surrogate ensuring the presence of good neutralizing activity. In selecting good COVID-19-convalescent plasmas, quantification of neutralizing activity in each plasma sample before collection and use is required.
    Convalescent plasma
    Citations (50)
    Despite effective vaccination programs, waning immunity in the vaccinated populations and the emergence of variants of concern posed a risk of breakthrough infections. A booster dose was demonstrated to provide substantially increased protection against symptomatic disease and hospitalization. We aimed to evaluate immune memory and the efficacy of reducing the rate of SARS-CoV-2 infection post heterologous booster with CORBEVAX after primary vaccination with two doses of COVISHIELD. SARS-CoV-2 S1/S2 spike IgG and RBD-specific antibody responses were elicited with both booster vaccines, with a greater response in individuals receiving heterologous booster. T and B memory responses were increased with booster dose, whereas B memory needed a longer duration to develop in individuals who received a homologous booster (90 days) in comparison to a heterologous booster (30 days). RBD-specific B memory and antibody-secreting (non-memory) B lymphocytes were enhanced with both boosters; however, the duration of response was longer with the heterologous booster compared to the homologous, indicating greater protection with the heterologous booster. The rate of infection 14 days after administration of the heterologous booster was comparatively lower than that of the homologous booster, with the symptoms being much less or asymptomatic.
    Booster (rocketry)
    Heterologous
    Booster dose
    Citations (7)
    Booster vaccination with messenger RNA (mRNA) vaccines has been offered to adults in England starting on 14 September 2021. We used a test-negative case-control design to estimate the relative effectiveness of a booster dose of BNT162b2 (Pfizer-BioNTech) compared to only a two-dose primary course (at least 175 days after the second dose) or unvaccinated individuals from 13 September 2021 to 5 December 2021, when Delta variant was dominant in circulation. Outcomes were symptomatic coronavirus disease 2019 (COVID-19) and hospitalization. The relative effectiveness against symptomatic disease 14-34 days after a BNT162b2 or mRNA-1273 (Moderna) booster after a ChAdOx1-S (AstraZeneca) and BNT162b2 as a primary course ranged from around 85% to 95%. Absolute vaccine effectiveness ranged from 94% to 97% and was similar in all age groups. Limited waning was seen 10 or more weeks after the booster. Against hospitalization or death, absolute effectiveness of a BNT162b2 booster ranged from around 97% to 99% in all age groups irrespective of the primary course, with no evidence of waning up to 10 weeks. This study provides real-world evidence of substantially increased protection from the booster vaccine dose against mild and severe disease irrespective of the primary course.
    Booster (rocketry)
    Booster dose
    2019-20 coronavirus outbreak
    Citations (369)
    Abstract Using a prospective national cohort of 3.75 million individuals aged 20 or older, we evaluated the effectiveness against COVID-19 related ICU admissions and death of mRNA-based second vaccine boosters for four different three-dose background regimes: BNT162b2 primary series plus a homologous booster, and CoronaVac primary series plus an mRNA booster, a homologous booster, and a ChAdOx-1 booster. We estimated the vaccine effectiveness weekly from February 14 to August 15, 2022, by estimating hazard ratios of immunization over non-vaccination, accounting for relevant confounders. The overall adjusted effectiveness of a second mRNA booster shot was 88.2% (95%CI, 86.2-89.9) and 90.5% (95%CI 89.4-91.4) against ICU admissions and death, respectively. Vaccine effectiveness showed a mild decrease for all regimens and outcomes, probably associated with the introduction of BA.4 and BA.5 Omicron sub-lineages and immunity waning. The duration of effectiveness suggests that no additional boosters are needed six months following a second booster shot.
    Booster (rocketry)
    Booster dose
    Background: Vaccine covid-19 booster effectiveness (VBE) timing is not clearly known Objective: To compare the cases of covid-19 in vaccinated booster people with a time of <15 days vs. >= 15 days from booster to infection diagnosis and assess their relative VBE. Methodology: An observational, longitudinal and prospective study of adult patients with covid-19 breakthrough infections in booster vaccinated people, in general medicine and for the period December 2021 to February 2022, during the omicron variant contagion wave. Results: Forty-six cases were included, 15 cases of Covid-19 breakthrough infections with booster shot <15 days (33%) with a mean time in days from booster to diagnostic covid-19 of 6 days, and 31 cases with booster > = 15 days (67%) with a time in days from booster to covid-19 diagnostic of 37 days of mean. Relative VBE <15 days (cases where it can be considered that the booster is not yet effective) vs. > = 15 days (cases where it can be considered that the booster is already effective) [1 - (Cases with vaccine Booster shot < 15 days) / (Cases with vaccine Booster shot > = 15 days) x 100] was 60%. Covid-19 cases with booster shot <15 days had been more vaccinated with 2 doses of ChAdOx1 nCoV-19 vaccine (Vaxzevria, Oxford / AstraZeneca) plus booster of mRNA-1273 vaccine (Spikevax, formerly covid-19 Vaccine Moderna). Conclusion: In the general practice setting in Toledo, Spain, from December 1, 2021 to February 28, 2022, at the peak of omicron infections, booster after a period of <15 days provided 60% relative protection against symptomatic disease vs. > = 15 days. The results suggest that booster received <15 days provided early protection against SARS-CoV-2 infection of symptomatic Covid-19 of 60%. However, this result does not seem logical: this lower early risk may be transient and due to “vaccinated bias.”
    Booster (rocketry)
    Booster dose
    Citations (1)
    Summary The 7 S and 19 S rabbit antibodies to herpes simplex virus (HSV) from early and late (hyperimmune) sera differed in their ability to sensitize virus for subsequent neutralization by either complement (C′) or anti-γ-globulin (GAR). The early 7 S and 19 S antibodies showed low to negligible neutralizing activity in the absence of C′ or GAR. When C′ was added, however, both of these antibodies showed enhanced neutralizing activity. The early 7 S but not the early 19 S antibody was also capable of sensitizing virus for subsequent neutralization by GAR. The late 19 S antibody could neutralize virus in the absence of C′ or GAR, but its activity was enhanced in the presence of C′ or GAR. The late 7 S antibody showed high neutralizing activity in the absence of C′ or GAR. In the presence of C′, the neutralization rate constants (K) but not the neutralization titers of the late 7 S antibody were enhanced. In contrast, the neutralization titers of the late 7 S antibody were enhanced approximately threefold with GAR. The neutralizing activity of the early and late 19 S antibodies with C′ or GAR was sensitive to inactivation by 2-ME. Similarly, the neutralizing activity with C′ of the early 7 S antibody and the enhanced rate of neutralization with C′ of the late 7 S antibody were sensitive to inactivation by 2-ME. In contrast, 2-ME did not reduce the neutralization titers of the early and late 7 S antibodies in the presence of GAR.
    Citations (101)
    Eighty seven babies from mothers with positive HBsAg in sera were vaccinated with HBIG and HBV vaccine.When the titer of anti-HBS decreased to below 10(RIA S/N ratio) the booster injection was given during the following up period for 5 years.The level of anti-HBS rerose to more than 10 (RIA S/N ratio) in 39.2% of 166 times of booster injection.The GMT of RIA S/N ratio was from below 10 to 30.8.It was also observed that the immunoresponsibility to booster injection was closely correlated with the primary immunoresponsibility to HBV vaccine.In major of the babies responsed to primary HBV vaccination higher,the titer of anti-HBS after booster injection was higher,the required times of booster injection was fewer,and the effective level of anti-HBS was maintained longer.The study suggested that the status of immunity of organism not only determines the responsibility to the primary HBV vaccination but also determines the immunoresponsibility to the booster injeetion.The method of primary HBV vaccination and the dose of booster injection were not observed to relate to the immunoresponsibility of booster injection
    Booster (rocketry)
    Booster dose
    Citations (0)
    Israel began administering a BNT162b2 booster dose to restore protection following the waning of the 2-dose vaccine. Biological studies have shown that a "fresh" booster dose leads to increased antibody levels compared to a fresh 2-dose vaccine, which may suggest increased effectiveness. To compare the real-world effectiveness of a fresh (up to 60 days) booster dose with that of a fresh 2-dose vaccine, we took advantage of a quasi-experimental study that compares populations that were eligible to receive the vaccine at different times due to age-dependent policies. Specifically, we compared the confirmed infection rates in adolescents aged 12-14 (215,653 individuals) who received the 2-dose vaccine and in adolescents aged 16-18 (103,454 individuals) who received the booster dose. Our analysis shows that the confirmed infection rate was lower by a factor of 3.7 (95% CI: 2.7 to 5.2) in the booster group.
    Booster (rocketry)
    Booster dose
    Citations (12)
    Abstract Israel began administering a BNT162b2 booster dose to restore protection following the waning of the 2-dose vaccine. Biological studies have shown that a fresh booster leads to increased antibody levels compared to a fresh 2-dose vaccine, which may suggest increased effectiveness. To compare the real-world effectiveness of a fresh booster dose with that of a fresh 2-dose vaccine, we conduct a quasi-experimental study that compares populations that were eligible to receive the vaccine at different times due to age cutoff policies. Our analysis shows that a fresh booster increases protection against confirmed infection by 3.7 (95% CI: 2.7 to 5.2) fold compared to a fresh 2-dose vaccine.
    Booster (rocketry)
    Booster dose
    Cut-off
    Dose dependence