Administration Of Booster Dose Research Articles

COVID-19 Booster Vaccination Adverse Effects and Willingness to Receive a Yearly Booster Dose among Members of Health Sciences Faculties: A Descriptive Cross-Sectional Study

ABSTRACT Background: New severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants and waning vaccine efficacy led to the administration of booster doses. Healthcare workers (HCWs) are vulnerable to contract the infection, and vaccination hesitancy in this group may have an impact on vaccine uptake among the general public. Aims: This study aimed to (1) assess the prevalence of self-reported adverse effects (AEs) after the first booster dose vaccine, (2) evaluate the AEs between the homologous and heterologous booster vaccines, and (3) evaluate the willingness to receive a hypothetical yearly booster dose. Materials and Methods: An online, cross-sectional, self-administered, structured questionnaire was distributed to members of the health sciences faculties (HSFs), XXXX University, Malaysia. Convenience sampling was adopted, and descriptive statistics was used to interpret the results. Results: About 67.1% of participants experienced systemic or local AEs. The common AEs were pain at the site of injection (60.2%), fatigue (45.7%), headache (31.6%), and fever (24.7%). About 64% of our participants believed that the booster dose provided extra immunity against the coronavirus disease 2019 (COVID-19) infection and 57.7% of participants expressed concern over the “mix–match” of vaccination. About 78% of the participants were keen to receive the hypothetical yearly booster dose. The severity of AEs between the booster dose and the primary dose was statistically insignificant (P < 0.159). Conclusion: Booster vaccination AEs were similar to the primary dose. However, a higher severity of AEs occurring in heterologous vaccine receivers was noted in our study.

Immunogenicity and Safety of Half-Dose Heterologous mRNA-1273 Booster Vaccination for Adults Primed with the CoronaVac® and ChAdOx1-S Vaccines for SARS-CoV-2.

Coronavirus disease 2019 (COVID-19) has been extensively researched, particularly with regard to COVID-19 vaccines. However, issues with logistics and availability might cause delays in vaccination programs. Thus, the efficacy and safety of half-dose heterologous mRNA should be explored. This was an open-label observational study to evaluate the immunogenicity and safety of half-dose mRNA-1273 as a booster vaccine among adults aged >18 years who underwent a complete primary SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) vaccination regimen with CoronaVac® and ChAdOx1-S. Adverse events (AEs), seropositivity rate, seroconversion, geometric mean titer (GMT) of SARS-CoV-2 antibodies, neutralizing antibodies, and T cells (CD4+ and CD8+) specific for SARS-CoV-2 were analyzed. Two hundred subjects were included in the final analysis, with 100 subjects in each priming vaccine group. Most of the AEs were mild, with systemic manifestations occurring between 1 and 7 days following vaccination. A significant difference was observed in the GMT and seropositivity rate following booster dose administration between the two groups. CD8+/CD3+, IFN (interferon)-producing CD8+, and TNF (tumor necrosis factor)-producing CD8+ cells showed significant increases in both groups. The administration of the half-dose mRNA-1273 booster is safe and effective in increasing protection against SARS-CoV-2 infection.

The Effectiveness of the Third Dose of COVID-19 Vaccine: When Should It Be Performed?

COVID-19 vaccination is the most significant step toward the long-term mitigation of SARS-CoV-2-related complication, avoiding disease and death and decreasing virus spread. This study aimed to evaluate, in a real-world setting, booster dose effectiveness to reduce COVID-19 risk considering the amount of time after the end of the two-dose vaccination cycle. A sub-analysis was conducted to adjust the booster dose effect for occupational and demographic factors. About 16,000 COVID-19-vaccinated HCWs of three University Hospital Networks in Milan (HN1/HN2/HN3) were included in the study. Data were collected by Occupational Health Physicians of the HNs within specific computerized databases. In univariable analysis, booster dose administration displayed a slightly higher risk of infection with respect to not receiving it, OR = 1.18, with 95% confidence interval (C.I) [0.99, 1.41]. When the model was adjusted with the modulating effect of time from the completion of the vaccination cycle on booster dose administration, the latter resulted in strong protective effect against infection, OR = 0.43, 95% CI [0.26, 0.74]. However, considering the modifying influence of time from the vaccination cycle's completion, the administration of booster doses appeared to have a protective effect against infection. In HN1, students and resident physicians displayed lower odds of infection with respect to physicians. Lastly, a non-linear effect of age was reported. Our findings suggest that the correct timing in vaccine scheduling and administration is critical to vaccine effectiveness. These findings, applicable to all vaccinations, should help in setting up more effective vaccination strategies.

Comparison of homologous and heterologous inactivated and mRNA vaccination programme against SARS-CoV-2 in dialysis patients.

To evaluate the vaccine response and the effect of the booster dose on COVID-19 positivity in haemodialysis (HD) and peritoneal dialysis (PD) patients who received and did not receive BNT162b2 as a booster dose after two doses of CoronaVac. The study included 80 PD and 163 HD patients, who had been administered two doses of the CoronaVac. Antibody levels were measured on Days 42 and 90 after the first dose. Measurements were repeated on Day 181 after the first dose in the patients that received two vaccine doses and on Day 28 after the third dose in those that also received the booster dose. Antibody levels below 50 AU/mL were considered negative. The seropositivity rate was similar in the HD and PD group on Days 42 and 90 (p = 0.212 and 0.720). All patients were seropositive in the booster group. The antibody level was lower in the patients that received CoronaVac as the booster compared to those administered BNT162b2 in HD and PD groups (p < 0.001 and 0.002). COVID-19 positivity was detected in 11 patients (7 = had not received the booster dose, 4 = had received third dose of CoronaVac). The multivariate analysis revealed that as age increased, COVID-19 positivity also increased (OR: 1.080, 95% CI: 1.017 - 1.146, p = 0.012), while booster dose administration decreased this positivity (OR: 0.113, 95% CI: 0.028 - 0.457, p = 0.002). Our results may indicate the need for additional vaccination doses in patients with HD and PD. Our findings indicate a higher antibody response in dialysis patients with heterologous BNT162b2 as a booster dose after two doses of CoronaVac compared to homologous CoronaVac.

Safety Monitoring of COVID-19 Vaccines in Persons with Prior SARS-CoV-2 Infection: A European Multi-Country Study.

In all pivotal trials of COVID-19 vaccines, the history of previous SARS-CoV-2 infection was mentioned as one of the main exclusion criteria. In the absence of clinical trials, observational studies are the primary source for evidence generation. This study aims to describe the patient-reported adverse drug reactions (ADRs) following the first COVID-19 vaccination cycle, as well as the administration of booster doses of different vaccine brands, in people with prior SARS-CoV-2 infection, as compared to prior infection-free matched cohorts of vaccinees. A web-based prospective study was conducted collecting vaccinee-reported outcomes through electronic questionnaires from eleven European countries in the period February 2021-February 2023. A baseline questionnaire and up to six follow-up questionnaires collected data on the vaccinee's characteristics, as well as solicited and unsolicited adverse reactions. Overall, 3886 and 902 vaccinees with prior SARS-CoV-2 infection and having received the first dose or a booster dose, respectively, were included in the analysis. After the first dose or booster dose, vaccinees with prior SARS-CoV-2 infection reported at least one ADR at a higher frequency than those matched without prior infection (3470 [89.6%] vs. 2916 [75.3%], and 614 [68.2%] vs. 546 [60.6%], respectively). On the contrary side, after the second dose, vaccinees with a history of SARS-CoV-2 infection reported at least one ADR at a lower frequency, compared to matched controls (1443 [85.0%] vs. 1543 [90.9%]). The median time to onset and the median time to recovery were similar across all doses and cohorts. The frequency of adverse reactions was higher in individuals with prior SARS-CoV-2 infection who received Vaxzevria as the first dose and Spikevax as the second and booster doses. The frequency of serious ADRs was low for all doses and cohorts. Data from this large-scale prospective study of COVID-19 vaccinees could be used to inform people as to the likelihood of adverse effects based on their history of SARS-CoV-2 infection, age, sex, and the type of vaccine administered. In line with pivotal trials, the safety profile of COVID-19 vaccines was also confirmed in people with prior SARS-CoV-2 infection.

Protective role of SARS-CoV-2 anti-S IgG against breakthrough infections among European healthcare workers during pre and post-Omicron surge-ORCHESTRA project.

Anti SARS-CoV-2 vaccination initially showed high effectiveness in preventing COVID-19. However, after the surge of variants of concern, the effectiveness dropped. Several studies investigated if this was related to the decrease of the humoral response over time; however, this issue is still unclear. The aim of this study was to understand whether SARS-CoV-2 anti-S IgG levels can be used to predict breakthrough infection risk and define the timing for further booster doses administration. Within the framework of the ORCHESTRA Project, over 20,000 health workers from 11 European centers were enrolled since December 2020. We performed two Cox proportional hazards survival analyses regarding pre-Omicron (from January to July 2021) and Omicron (December 2021-May 2022) periods. The serological response was classified as high (above the 75th percentile), medium (25th-75th), or low (< 25th). Seventy-four (0.33%) and 2122 (20%) health workers were infected during the first and second periods, respectively. Both Cox analyses showed that having high anti-S titer was linked to a significantly lower risk of infection as compared to having medium serological response [HR of high vs medium anti-S titer = 0.27 (95% CI 0.11-0.66) during the first phase, HR = 0.76 (95% CI 0.62-0.93) during the second phase]. Vaccine effectiveness wanes significantly after new variants surge, making anti-S titer unsuitable to predict optimal timing for further booster dose administration. Studies on other immunological indicators, such as cellular immunity, are therefore needed to better understand the mechanisms and duration of protection against breakthrough infection risk.

Knowledge, acceptance, motivators and barriers of booster dose of COVID-19 vaccination among dental patients: A cross-sectional study.

Given the lingering threat of COVID infection, questions are being raised if coronavirus disease 2019 (COVID-19) vaccine needs annual or regular boosters to maintain high levels of immunity against both the original virus and variants. This study was designed to evaluate the knowledge, acceptance, motivators and barriers of the booster dose of COVID-19 vaccine among the dental patients of District Lucknow, India. A total of 297 respondents were selected by a convenience sampling method in this cross-sectional study from various dental clinics. An anonymous, self-administered, closed-ended questionnaire was used. Overall 37.7% respondents reported to have taken all 3 doses and 57.9% had taken single/double doses. Correct information about booster doses shows a significant association with the number of doses taken. The majority had information about the availability of the Pfizer booster vaccine (69.0%). About 58% of participants had information about the technology used in booster doses. The hesitancy for booster doses and the development of natural immunity by infection show significant associations with the number of doses taken. Only 18.2% patients had hesitation about the booster dose and most of them 78.8% recommended others to take the booster vaccine as soon as possible. The majority assumed that previous COVID-19 vaccines can help them get immune (21.5%) followed by not much research has been done on the booster vaccines (15.5%) and their chronic diseases warn them against the booster dose administration (12.5%). Nearly 18.2% of respondents had hesitation about booster dose and less than one third of the respondents trusted a government source for information about booster dose of COVID vaccine. Nearly 36 % did not know that the booster dose of COVID vaccine is available at health centers. Dental health professionals and policymakers should implement and support strategies to ensure people are vaccinated for COVID-19 booster doses.

Seroprevalence of SARS-CoV-2 anti-spike IgG antibody among COVID-19 vaccinated individuals residing in Surabaya, East Java, Indonesia.

To limit the SARS-CoV-2 transmission, the Indonesian government launched a COVID-19 vaccination program in January 2021. Studies on the clinical treatment and implementation of COVID-19 vaccination have shown promising results; however, it is necessary to estimate the effectiveness of the vaccines. With the ongoing COVID-19 pandemic, studies have highlighted the impact of COVID-19 vaccines, especially CoronaVac, on Indonesian healthcare workers. To get a better picture of how the vaccines work in Indonesia, it is necessary to estimate the prevalence of SARS-CoV-2 anti-S IgG antibody induced by the COVID-19 vaccine in individuals who have already received two-to-three doses of vaccines. Four-hundred and ninety-six whole-blood samples were collected from participants residing in Surabaya, East Java, Indonesia, who received a minimum of a two-dose COVID-19 vaccine. Serums were then isolated from the blood and subjected to detect SARS-CoV-2 anti-S IgG antibodies using a lateral flow immunochromatographic assay. The prevalence of positive anti-S-IgG antibodies was 91.7% (455/496) in all participants receiving a minimum of a two-dose COVID-19 vaccine. As many as 209 (85.3%) and 141 (96.6%) participants were seropositive for receiving CoronaVac and AstraZeneca, respectively. Meanwhile, all participants receiving two-dose CoronaVac with one booster dose of Moderna (105/100%) were seropositive (p < 0.05). Age, comorbidity, and time after the last vaccine were significantly correlated with seropositivity (p < 0.05). Different vaccines might produce different antibody responses. Adopting a stronger policy regarding the administration of booster doses might be beneficial to elicit positive anti-S-IgG antibodies, especially among older individuals, those with comorbid diseases, and those with a longer time after the second vaccination dose.

Evaluation of dynamics of immune responses and protective efficacy in piglets immunized with an inactivated porcine reproductive and respiratory syndrome vaccine candidate

Porcine Reproductive and Respiratory Syndrome (PRRS) is an important viral disease of swine that causes significant mortality in piglets and production losses in adult pigs. In this study, we investigated the protective efficacy of an inactivated PRRS virus vaccine candidate and evaluated the differences in PRRSV specific anamnestic response in piglets when challenged with live PRRSV at two different intervals post-immunization. Six-week-old piglets were immunized intramuscularly with an inactivated, Montanide ISA-206 adjuvanted Indian PRRSV isolate, followed by a booster dose at 21 days post-immunization. Homologous live PRRS virus challenge was done on 60 and 180 days post-booster (dpb). We assessed humoral and cell-mediated immune responses at various intervals post-immunization and after challenge. Viraemia, virus shedding in nasal secretions and lung lesion scores were studied to assess the efficacy of the vaccine candidate. All the immunized pigs developed PRRSV-specific antibodies upon booster dose administration. Neutralizing antibody (NA) titres before challenge, in most animals, ranged between 0 and 4. Potentially protective NA titre of 8 was observed in serum of seven out of the 12 immunized piglets after challenge, across the immunized groups. A significant increase in the mean T-helper, T-cytotoxic, memory or activated T-helper and NK cell populations was observed in immunized piglets challenged at 180 dpb, from 4 to 11 dpc, 5 to 11 dpc, 5 to 7 dpc and 6 to 11 dpc, respectively as compared to the challenge controls. Protective efficacy of the inactivated PRRSV antigen against the homologous virus challenge was evidenced by earlier onset of PRRSV specific virus neutralizing antibodies and cell mediated immune responses, reduced viremia, nasal virus shedding and severity of lung lesions in immunized piglets as compared to unimmunized controls post-challenge. Our results indicated that the inactivated PRRSV antigen elicited better virus specific anamnestic immune responses in piglets when challenged at six months after the single booster dose, due to age related increase in antigen-specific memory T helper cell responses, as compared to those challenged at 2 months post booster.

Homologous or heterologous COVID-19 vaccine schemes: comparison of immune responses and side effects

Real-life data are needed regarding the appropriate time and selection of vaccination strategies, homologous or heterologous. We aimed to compare neutralizing antibody levels and side effects in different vaccination schemes. The study included 310 Health Care Workers (HCWs) vaccinated with 5 different schemes. Antispike/RBD IgG levels were measured between 28 and 60 days after the last dose. Side effects in participants were recorded, and pharmacovigilance records were reviewed from the outpatient vaccine clinic. Mean age of the participants was 38 ± 11 years of whom 226 (72.9%) were female, and 84 (27.1%) were male. After booster doses, increasing antibody levels were detected in all groups. Mean antibody levels were detected to be statistically lower in 3 doses of inactivated vaccines group. The side effects were no significant difference between groups. Booster dose administration with mRNA vaccines stands out as the most accurate strategy for those at risk of contracting severe COVID-19 and HCWs caring for this population.

Evaluation of potential adverse events following COVID-19 mRNA vaccination among adults aged 65 years and older: Two self-controlled studies in the U.S.

BackgroundOur near-real-time safety monitoring of 16 adverse events (AEs) following COVID-19 mRNA vaccination identified potential elevation in risk for six AEs following primary series and monovalent booster dose administration. The crude association with AEs does not imply causality. Accordingly, we conducted robust evaluation of potential associations. MethodsWe conducted two self-controlled case series studies of COVID-19 mRNA vaccines (BNT162b2 and mRNA-1273) in U.S. Medicare beneficiaries aged ≥ 65 years. Adjusted incidence rate ratio (IRRs) and 95 % confidence intervals (CIs) were estimated following primary series doses for acute myocardial infarction (AMI), pulmonary embolism (PE), immune thrombocytopenia (ITP), disseminated intravascular coagulation (DIC); and following monovalent booster doses for AMI, PE, ITP, Bell’s Palsy (BP) and Myocarditis/Pericarditis (Myo/Peri). ResultsThe primary series study included 3,360,981 individuals who received 6,388,542 primary series doses; the booster study included 6,156,100 individuals with one monovalent booster dose. The AMI IRR following BNT162b2 primary series and booster was 1.04 (95 % CI: 0.91 to 1.18) and 1.06 (95 % CI: 1.003 to 1.12), respectively; for mRNA-1273 primary series and booster, 1.01 (95 % CI: 0.82 to 1.26) and 1.05 (95 % CI: 0.998 to 1.11), respectively. The hospital inpatient PE IRR following BNT162b2 primary series and booster was 1.19 (95 % CI: 1.03 to 1.38) and 0.86 (95 % CI: 0.78 to 0.95), respectively; for mRNA-1273 primary series and booster, 1.15 (95 % CI: 0.94 to 1.41) and 0.87 (95 % CI: 0.79 to 0.96), respectively. The studies’ results do not support that exposure to COVID-19 mRNA vaccines elevate the risk of ITP, DIC, Myo/Peri, and BP. ConclusionWe did not find an increased risk for AMI, ITP, DIC, BP, and Myo/Peri and there was not consistent evidence for PE after exposure to COVID-19 mRNA primary series or monovalent booster vaccines. These results support the favorable safety profile of COVID-19 mRNA vaccines administered in the U.S. elderly population.

Immunogenicity and safety of homologous and heterologous booster vaccination of ChAdOx1 nCoV-19 (COVISHIELD™) and BBV152 (COVAXIN®): a non-inferiority phase 4, participant and observer-blinded, randomised study.

Primary SARS-CoV-2 vaccination has been shown to wane with time and provide lower protection from disease with new viral variants, prompting the WHO to recommend the administration of booster doses. We determined the safety and immunogenicity of homologous or heterologous boosters with ChAdOx1 nCoV-19 (COVISHIELD™) or BBV152 (COVAXIN®), the two vaccines used widely for primary immunization in India, in participants who had already received two primary doses of these vaccines. Participants primed with two doses each of COVISHIELD™ or COVAXIN® 12-36 weeks previously, were randomised to receive either COVISHIELD™ or COVAXIN® booster in a 1:1 ratio. The primary outcome was day 28 post-booster anti-spike IgG seropositivity and secondary outcomes were anti-spike IgG levels and assessment of safety and reactogenicity. The results of 90 days intention-to-treat analysis are presented. This trial is registered with ISRCTN (CTRI/2021/08/035648). In the COVISHIELD™ primed group with 200 participants, the seropositivity 28 days post booster in the heterologous COVAXIN® arm was 99% and non-inferior to the homologous COVISHIELD™ arm, which was also 99% (difference 0%; 95% CI:-2.8% to 2.7%). The geometric mean concentration (GMC) of anti-spike antibodies following heterologous COVAXIN® boost on day 28 was 36,190.78 AU/mL (95% CI: 30,526.64-42,905.88) while the GMC following homologous COVISHIELD™ boost was 97,445.09 AU/mL (82,626.97-114,920.7). In the COVAXIN® primed group with 204 participants, the seropositivity 28 days post booster in the heterologous COVISHIELD™ arm was 100% and non inferior to the homologous COVAXIN® arm which was 96% (difference 4%, 95% CI: 0.2%-7.8%). The GMC following heterologous COVISHIELD™ boost was 241,681.6 AU/mL (95% CI: 201,380.2-290,048.3) compared to homologous COVAXIN® boost, which was 48,473.94 AU/mL (95% CI: 38,529.56-60,984.95). The day 28 geometric mean ratio (GMR) of the anti-spike IgG between the heterologous and homologous boosted arms was 0.42 (95% CI: 0.34-0.52) in the COVISHIELD™ primed group and 5.11 (95% CI: 3.83-6.81) in the COVAXIN® primed group. There were no related serious adverse events reported in any group. Homologous and heterologous boosting with COVISHIELD™ or COVAXIN® in COVISHIELD™ or COVAXIN® primed individuals are immunogenic and safe. A heterologous boost with COVISHIELD™ after COVAXIN® prime offers the best immune response among the four combinations evaluated. Azim Premji Foundation and Bill and Melinda Gates Foundation.

Waning effectiveness against COVID-19-related hospitalization, severe complications, and mortality with two to three doses of CoronaVac and BNT162b2: a case–control study

ABSTRACT Background: This study aims to evaluate waning effectiveness against severe and fatal COVID-19 with two to three doses of CoronaVac/BNT162b2, where data are limited. Methods: A case–control study included individuals aged ≥18 years, unvaccinated or received two to three doses of CoronaVac/BNT162b2, using electronic healthcare databases in Hong Kong. Those with first COVID-19-related hospitalization, severe complications, or mortality between 1 January and 15 August 2022 were defined as cases and matched with up-to-10 controls by age, sex, index date, and Charlson Comorbidity Index. Vaccine effectiveness (VE) against COVID-19-related outcomes was estimated at different time intervals from second and third-dose vaccination (0–13 up-to 210–240 days) using conditional logistic regression adjusted for comorbidities and medications. Results: By 211–240 days after second dose, VE against COVID-19-related hospitalization reduced to 46.6% (40.7–51.8%) for BNT162b2 and 36.2% (28.0–43.4%) for CoronaVac, and VE against COVID-19-related mortality were 73.8% (55.9–84.4%) and 76.6% (60.8–86.0%). After third dose, VE against COVID-19-related hospitalization decreased from 91.2% (89.5–92.6%) for BNT162b2 and 76.7% (73.7–79.4%) for CoronaVac at 0–13 days, to 67.1% (60.4–72.6%) and 51.3% (44.2–57.5%) at 91–120 days. VE against COVID-19-related mortality for BNT162b2 remained high from 0–13 days [98.2% (95.0–99.3%)] to 91–120 days [94.6% (77.7–98.7%)], and for CoronaVac reduced from 0–13 days [96.7% (93.2–98.4%)] to 91–120 days [86.4% (73.3–93.1%)]. Conclusions: Significant risk reduction against COVID-19-related hospitalization and mortality after CoronaVac or BNT162b2 vaccination was observed for >240 and >120 days after second and third doses compared to unvaccinated, despite significant waning over time. Timely administration of booster doses could provide higher levels of protection.

Safety and efficacy beliefs on covid-19 vaccination in perspective of the second booster dose administration: A survey experiment in the italian population

Safety and efficacy beliefs on covid-19 vaccination in perspective of the second booster dose administration: A survey experiment in the italian population

Axillary Lymphadenopathy After a COVID-19 Vaccine Booster Dose: Time to Resolution on Ultrasound Follow-Up and Associated Factors.

BACKGROUND. Because administration of booster doses of COVID-19 vaccines is ongoing, radiologists are continuing to encounter COVID-19 vaccine-related axillary lymphadenopathy on imaging. OBJECTIVE. The purposes of this study were to assess time to resolution of COVID-19 vaccine-related axillary lymphadenopathy identified on breast ultrasound after administration of a booster dose and to assess factors potentially associated with time to resolution. METHODS. This retrospective single-institution study included 54 patients (mean age, 57 years) with unilateral axillary lymphadenopathy ipsilateral to the site of injection of a booster dose of mRNA COVID-19 vaccine visualized on ultrasound (whether an initial breast imaging examination or follow-up to prior screening or diagnostic breast imaging) performed between September 1, 2021, and December 31, 2022, and who underwent follow-up ultrasound examinations until resolution of lymphadenopathy. Patient information was extracted from the EMR. Univariable and multivariable linear regression analyses were used to identify predictors of time to resolution. Time to resolution was compared with that in a previously described sample of 64 patients from the study institution that was used to evaluate time to resolution of axillary lymphadenopathy after the initial vaccination series. RESULTS. Six of the 54 patients had a history of breast cancer, and two had symptoms related to axillary lymphadenopathy (axillary pain in both patients). Among the 54 initial ultrasound examinations showing lymphadenopathy, 33 were screening examinations and 21 were diagnostic examinations. Lymphadenopathy had resolved a mean of 102 ± 56 days after administration of the booster dose and 84 ± 49 days after the initial ultrasound showing lymphadenopathy. Age, vaccine booster type (Moderna vs Pfizer-BioNTech), and history of breast cancer were not significantly associated with time to resolution in univariable or multivariable analyses (all p > .05). Time to resolution after administration of a booster dose was significantly shorter than time to resolution after administration of the first dose in the initial series (mean, 129 ± 37 days) (p = .01). CONCLUSION. Axillary lymphadenopathy after administration of a COVID-19 vaccine booster dose has a mean time to resolution of 102 days, shorter than the time to resolution after the initial vaccination series. CLINICAL IMPACT. The time to resolution after administration of a booster dose supports the current recommendation for a follow-up interval of at least 12 weeks when vaccine-related lymphadenopathy is suspected.

Impact of BNT162b2 Booster Dose on SARS-CoV-2 Anti-Trimeric Spike Antibody Dynamics in a Large Cohort of Italian Health Care Workers.

Accurate studies on the dynamics of Pfizer-Biontech BNT162b2-induced antibodies are crucial to better tailor booster dose administration depending on age, comorbidities, and previous natural infection with SARS-CoV-2. To date, little is known about the durability and kinetics of antibody titers months after receiving a booster dose. In this work, we studied the dynamic of anti-Trimeric Spike (anti-TrimericS) IgG titer in the healthcare worker population of a large academic hospital in Northern Italy, in those who had received two vaccine doses plus a booster dose. Blood samples were collected on the day of dose 1, dose 2, then 1 month, 3 months, and 6 months after dose 2, the day of the administration of the booster dose, then 1 month and 3 months after the booster dose. The vaccination immunogenicity was evaluated by dosing anti-TrimericS IgG titer, which was further studied in relation to SARS-CoV-2 infection status, age, and sex. Our results suggest that after the booster dose, the anti-TrimericS IgG production was higher in the subjects that were infected only after the completion of the vaccination cycle, compared to those that were infected both before and after the vaccination campaign. Moreover, the booster dose administration exerts a leveling effect, mitigating the differences in the immunogenicity dependent on sex and age.

Autopsies Revealed Pathological Features of COVID-19 in Unvaccinated vs. Vaccinated Patients.

Background: In Italy, by the end of 2021, a new pandemic wave led to increased hospitalizations and death, even in some vaccinated people. We aimed to investigate the death of COVID-19-vaccinated patients who acquired infection and developed severe disease, and to assess differences with fatal COVID-19 in unvaccinated subjects by studying the pathological events triggered by SARS-CoV-2. Methods: Detailed autoptic examination was performed on five fully vaccinated compared to five unvaccinated patients. Histopathological analysis focused on the lung and heart, the two major affected organs. Results: COVID-19 caused, or contributed to death, in all the unvaccinated cases. By contrast, in vaccinated group, pre-existing pathologies played a major role, and death was not COVID-19-related in four out of five patients. These patients did not show the histological features of SARS-CoV-2 lung damage. Diffuse inflammatory macrophages infiltration recently emerged as the main feature of COVID-19 cardiac injury. Interestingly, the most striking difference between the two groups was the absence of increased macrophage infiltration in the heart of vaccinated patients. Conclusions: Results of this study confirm the efficacy of anti-SARS-CoV-2 vaccination in protecting organs from injury and support the need to maintain an adequate immune response by booster dose administration.

Cellular and Humoral Responses in Dialysis Patients after Vaccination with the BNT162b2 or mRNA-1273 Vaccines

The outbreak of SARS-CoV-2 has raised considerable concern about the detrimental effects it can induce in public health, with the interest of the scientific community being focused on the development of preventive and therapeutic approaches. Patients with end-stage renal disease (ESRD) are amongst vulnerable populations for critical illness owing to the presence of other comorbidities, their defective immune system, and their inability of self-isolation. To date, vaccination constitutes the most promising method to manage viral dispersion. Therefore, it is particularly important to investigate the effectiveness of available vaccines against SARS-CoV-2 in this risk group. Here, we summarize initial experience regarding the humoral and cellular immune responses elicited in dialysis patients after completion of the recommended vaccination regimen, as well as after booster dose administration, with one of the two mRNA vaccines, namely, BNT162b2 and mRNA-1273. In conclusion, a significantly diminished and delayed immune pattern was observed in ESRD patients compared to healthy population, with a peak in antibody titers occurring 3-5 weeks after the second dose. A booster dose significantly augmented the immune response in dialysis patients with either mRNA-based vaccine. Variables adversely correlating with the weak immunogenicity observed in dialysis patients include immunosuppressive therapy, older age, comorbidities, longer time in hemodialysis treatment, and higher body mass index. On the contrary, previous COVID-19 infection and administration of the mRNA-1273 vaccine are deemed to induce a more favorable immune response. Further investigation is needed to thoroughly understand the efficacy of mRNA-based vaccines in hemodialysis patients and define predictive factors that can influence it.

Transition of Antibody Titers after SARS-CoV-2 mRNA Vaccination in Japanese Healthcare Workers.

Since February 2021, healthcare workers in Japan have been preferentially vaccinated with a messenger RNA vaccine (BNT162b2; Pfizer/BioNTech) against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). While many studies have confirmed that this vaccine is highly effective in reducing hospitalization and deaths from coronavirus disease 2019 (COVID-19), antibody titers tend to decline at 3 months after vaccination, leading to a risk of breakthrough infections. Thus, information is needed to support the decision regarding the 3rd vaccination. In this study, we investigated the transition of anti-SARS-CoV-2 spike protein receptor-binding domain (RBD) IgG and neutralizing antibody titers in 37 vaccinated Japanese healthcare workers. Samples were collected 6 times starting before vaccination until 6 months after the second vaccination. The levels of anti-SARS-CoV-2 RBD IgG peaked 1 week after the 2nd vaccination, then declined over time and decreased to < 10% at 6 months after the 2nd vaccination. Additionally, approximately one-third of the healthcare workers were seronegative for the Omicron variant 6 months after the 2nd vaccination. Workers with low anti-SARS-CoV-2 RBD IgG levels also had low neutralizing antibody titers. These data support booster dose administration for healthcare workers, especially those with low anti-SARS-CoV-2 RBD IgG levels.

The Influence of Booster Shot and SARS-CoV-2 Infection on the Anti-Spike Antibody Concentration One Year after the First COVID-19 Vaccine Dose Administration.

This study pictures the humoral response of 100 vaccinees to Pfizer/BioNTech COVID-19 vaccine over a year, with particular focus on the influence of a booster shot administered around 10 months after the primary immunization. The response to the vaccination was assessed with Diasorin's SARS-CoV-2 TrimericSpike IgG. Abbott's SARS-CoV-2 Nucleocapsid IgG immunoassay was used to identify SARS-CoV-2 contact, even asymptomatic. In contrast to the gradual decline of the anti-spike IgG between 30 and 240 days after the first dose, an increase was noted between days 240 and 360 in the whole cohort. However, a statistically significant rise was seen only in boosted individuals, and this effect of the booster decreased over time. An increase was also observed in non-boosted but recently infected participants and a decrease was reported in non-boosted, non-infected subjects. These changes were not statistically significant. On day 360, a percentage of new SARS-CoV-2 infections was statistically lower in the boosted vs. non-boosted subgroups. The booster immunization is the most efficient way of stimulating production of anti-spike, potentially neutralizing antibodies. The response is additionally enhanced by the natural contact with the virus. Individuals with a low level of anti-spike antibodies may benefit the most from the booster dose administration.