Antibody Responses in Seropositive Persons after a Single Dose of SARS-CoV-2 mRNA Vaccine

The impact of previous SARS-CoV-2 infection on post-vaccine adverse events in individuals vaccinated with TURKOVAC or CoronaVac -inactivated COVID-19 vaccines

This study- a secondary analysis of data from a randomized, observer-blinded, non-inferiority study among volunteers between 18-55 y old in Türkiye- evaluated the impact of previous SARS-CoV-2 infection before the first dose of inactive TURKOVAC on post-vaccine local and systemic adverse events (AEs) comparing with CoronaVac. Of 1266 participants analyzed, 27.7% had a previous COVID-19 history. Local and systemic AEs were observed in 37.3% and 39% of the participants. The frequency of AEs was slightly higher in the first 30 minutes and 24 hours among participants with a COVID-19 history; none were severe. 1203 participants had a second dose vaccination, and 27.3% had a history of COVID-19. The frequencies of local and systemic AEs after the second dose were similar between those with and without a COVID-19 history. The TURKOVAC and CoronaVac showed similar frequencies of local and systemic AEs in the first 30 minutes after vaccination.

Post-Hoc Analysis of Potential Correlates of Protection of a Recombinant SARS-CoV-2 Spike Protein Extracellular Domain Vaccine Formulated with Advax-CpG55.2-Adjuvant

SpikoGen® vaccine is a subunit COVID-19 vaccine composed of an insect cell expressed recombinant spike protein extracellular domain formulated with Advax-CpG55.2™ adjuvant. A randomized double-blind, placebo-controlled Phase II clinical trial was conducted in 400 adult subjects who were randomized 3:1 to receive two intramuscular doses three weeks apart of either SpikoGen® vaccine 25 μg or saline placebo, as previously reported. This study reports a post hoc analysis of the trial data to explore potential immune correlates of SpikoGen® vaccine protection. A range of humoral markers collected pre- and post-vaccination, including spike- and RBD-binding IgG and IgA, surrogate (sVNT), and conventional (cVNT) virus neutralization tests were compared between participants who remained infection-free or got infected over three months of follow-up. From 2 weeks after the second vaccine dose, 21 participants were diagnosed with SARS-CoV-2 infection, 13 (4.2%) in the SpikoGen® group and 8 (9%) in the placebo group. Those in the vaccinated group who experienced breakthrough infections had significantly lower sVNT titers (GMT 5.75 μg/mL, 95% CI; 3.72-8.91) two weeks after the second dose (day 35) than those who did not get infected (GMT 21.06 μg/mL, 95% CI; 16.57-26.76). Conversely, those who did not develop SARS-CoV-2 infection during follow-up had significantly higher baseline sVNT, cVNT, spike-binding IgG and IgA, and RBD-binding IgG, consistent with a past SARS-CoV-2 infection. SpikoGen® further reduced the risk of re-infection (OR 0.29) in baseline seropositive (previously infected) as well as baseline seronegative participants. This indicates that while SpikoGen vaccine is protective in seronegative individuals, those with hybrid immunity have the most robust protection.

Hybrid immunity after BNT162b2 Covid-19 vaccine administration in children aged 5 to 11 years

BACKGROUND

The immune response to coronavirus disease 2019 (COVID-19) vaccination is stronger among adults with prior infection (hybrid immunity). It is important to understand if children demonstrate a similar response to better inform vaccination strategies. Our study investigated the humoral response after BNT162b2 COVID-19 vaccine doses in SARS-CoV-2 naïve and recovered children (5-11 years).

METHODS

A multi-institutional, longitudinal, prospective cohort study was conducted. Children were enrolled in a case-ascertained antibody surveillance study in Ottawa, Ontario from September/2020-March/2021; at least one household member was severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) positive on RT-PCR. In November 2021, BNT162b2 COVID-19 vaccine was authorized for children aged 5-11 in Canada. Children enrolled in the surveillance study intending to receive two vaccine doses were invited to participate in this study from November 2021-April 2022. Main exposure was prior SARS-CoV-2 infection, defined by positive RT-PCR or SARS-CoV-2 anti-N IgG antibody presence. Primary outcome was spike IgG antibody levels measured following the first vaccine dose (2-3 weeks) and second vaccine dose (3-4 weeks).

RESULTS

Of the 153 eligible children, 75 participants (median age 8.9 IQR (7.4, 10.2) years; 38 (50.7 %) female; 59 (78.7 %) Caucasian) had complete follow-up. Fifty-four (72 %) children had prior SARS-COV-2 infection. Spike IgG antibody levels are significantly higher in SARS-CoV-2 recovered participants after receiving the first dose (p < 0.001) and the second (p = 0.01) compared to infection naïve children.

CONCLUSIONS AND RELEVANCE

SARS-CoV-2 recovered children (5-11 years) demonstrated higher antibody levels following first BNT162b2 vaccine dose compared with naïve children. Most reached antibody saturation two to three weeks after the first dose; a second dose didn't change the saturation level. A single vaccine dose in SARS-CoV-2 recovered children may be equivalent or superior to a 2-dose primary series in naïve children. Further research is needed on the durability and quality of a single vaccine dose in this population.

Vaccine and antiviral drug promise for preventing post-acute sequelae of COVID-19, and their combination for its treatment

Introduction

Most healthy individuals recover from acute SARS-CoV-2 infection, whereas a remarkable number continues to suffer from unexplained symptoms, known as Long COVID or post-acute COVID-19 syndrome (PACS). It is therefore imperative that methods for preventing and treating the onset of PASC be investigated with the utmost urgency.

Methods

A mathematical model of the immune response to vaccination and viral infection with SARS-CoV-2, incorporating immune memory cells, was developed.

Results and discussion

Similar to our previous model, persistent infection was observed by the residual virus in the host, implying the possibility of chronic inflammation and delayed recovery from tissue injury. Pre-infectious vaccination and antiviral medication administered during onset can reduce the acute viral load; however, they show no beneficial effects in preventing persistent infection. Therefore, the impact of these treatments on the PASC, which has been clinically observed, is mainly attributed to their role in preventing severe tissue damage caused by acute viral infections. For PASC patients with persistent infection, vaccination was observed to cause an immediate rapid increase in viral load, followed by a temporary decrease over approximately one year. The former was effectively suppressed by the coadministration of antiviral medications, indicating that this combination is a promising treatment for PASC.

Safety and antibody response of the BNT162b2 SARS-CoV-2 vaccine in children aged 5-11 years with underlying diseases: A prospective observational study

BACKGROUND

Data on the safety and antibody response of the BNT162b2 severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mRNA vaccine in children aged 5-11 years with underlying diseases are limited. Thus, our study aimed to address this gap.

METHODS

This prospective observational study investigated the antibody titers for SARS-CoV-2 spike protein receptor-binding domain (S-IgG) and nucleocapsid protein (N-IgG) in patients aged 5-11 years with chronic underlying diseases following two doses of BNT162b2. Additionally, a questionnaire was used to assess adverse events (AEs) arising within 7 days after each dose. Data on severe AEs arising within 28 days after each dose were extracted from the patients' electronic medical records.

RESULTS

Among 122 patients, 24.6% (30/122) were immunocompromised. Furthermore, 79 patients experienced at least one AE following vaccination, but all recovered without sequelae, including one severe case after the first dose. The seropositivity rate after the second dose was 99.1% (116/117). Excluding 19 N-IgG-positive patients, the geometric mean antibody titer (GMT) was significantly higher in immunocompetent patients than in immunocompromised patients (1496 U/mL [95% confidence interval 1199-1862] vs. 472 U/mL [200-1119], p = 0.035). Additionally, the GMT of S-IgG was higher in N-IgG-positive patients than in N-IgG-negative patients (8203 [5847-11482] U/mL vs. 1127 [855-1486] U/mL, p < 0.001).

CONCLUSIONS

BNT162b2 is acceptably safe and immunogenic for children aged 5-11 years with underlying diseases. Although seroconversion was satisfactory in immunocompromised patients, the titers were lower than in immunocompetent patients.

Physiological Response to the COVID-19 Vaccine: Insights From a Prospective, Randomized, Single-Blinded, Crossover Trial

BACKGROUND

Rapid development and implementation of vaccines constituted a crucial step in containing the COVID-19 pandemic. A comprehensive understanding of physiological responses to these vaccines is important to build trust in medicine.

OBJECTIVE

This study aims to investigate temporal dynamics before and after COVID-19 vaccination in 4 physiological parameters as well as the duration of menstrual cycle phases.

METHODS

In a prospective trial, 17,825 adults in the Netherlands wore a medical device on their wrist for up to 9 months. The device recorded their physiological signals and synchronized with a complementary smartphone app. By means of multilevel quadratic regression, we examined changes in wearable-recorded breathing rate, wrist skin temperature, heart rate, heart rate variability, and objectively assessed the duration of menstrual cycle phases in menstruating participants to assess the effects of COVID-19 vaccination.

RESULTS

The recorded physiological signals demonstrated short-term increases in breathing rate and heart rate after COVID-19 vaccination followed by a prompt rebound to baseline levels likely reflecting biological mechanisms accompanying the immune response to vaccination. No sex differences were evident in the measured physiological responses. In menstruating participants, we found a 0.8% decrease in the duration of the menstrual phase following vaccination.

CONCLUSIONS

The observed short-term changes suggest that COVID-19 vaccines are not associated with long-term biophysical issues. Taken together, our work provides valuable insights into continuous fluctuations of physiological responses to vaccination and highlights the importance of digital solutions in health care.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

RR2-10.1186/s13063-021-05241-5.

Measures of population immunity can predict the dominant clade of influenza A (H3N2) in the 2017-2018 season and reveal age-associated differences in susceptibility and antibody-binding specificity

Background

For antigenically variable pathogens such as influenza, strain fitness is partly determined by the relative availability of hosts susceptible to infection with that strain compared to others. Antibodies to the hemagglutinin (HA) and neuraminidase (NA) confer substantial protection against influenza infection. We asked if a cross-sectionalantibody-derived estimate of population susceptibility to different clades of influenza A (H3N2) could predict the success of clades in the following season.

Methods

We collected sera from 483 healthy individuals aged 1 to 90 years in the summer of 2017 and analyzed neutralizing responses to the HA and NA of representative strains using Focus Reduction Neutralization Tests (FNRT) and Enzyme-Linked Lectin Assays (ELLA). We estimated relative population-average and age-specific susceptibilities to circulating viral clades and compared those estimates to changes in clade frequencies in the following 2017-18 season.

Results

The clade to which neutralizing antibody titers were lowest, indicating greater population susceptibility, dominated the next season. Titers to different HA and NA clades varied dramatically between individuals but showed significant associations with age, suggesting dependence on correlated past exposures.

Conclusions

This study indicates how representative measures of population immunity might improve evolutionary forecasts and inform selective pressures on influenza.

Association between Reactogenicity and Immunogenicity in a Vaccinated Cohort with Two mRNA SARS-CoV-2 Vaccines at a High-Complexity Reference Hospital: A Post Hoc Analysis on Immunology Aspects of a Prospective Cohort Study

Enhancing our comprehension of mRNA vaccines may facilitate the future design of novel vaccines aimed at augmenting immune protection while minimising reactogenic responses. Before this design is carried out, it is important to determine whether adaptive immunity correlates with the reactogenicity profile of vaccines. We studied a large cohort that was vaccinated with mRNA vaccines to answer this question. This was an observational study with real-world data. Reactogenicity data were obtained from the VigilVacCOVID study. Immunogenicity (humoral and cellular) data were retrieved from health records. One main population (n = 215) and two subpopulations were defined (subpopulation 1, n = 3563; subpopulation 2, n = 597). Sensitivity analyses were performed with subpopulations 1 and 2 to explore the consistency of results. We analysed the association of the intensity and types of adverse reactions with the development and quantity of elicited antibody titres. As an exploratory analysis in subpopulation 1, we assessed the association between reactogenicity and cellular immunogenicity. A higher incidence of fever, malaise, and myalgia including severe cases was significantly associated with the development and quantity of positive antibody titres. No significant findings were observed with cellular immunity. We observed a positive association between immunogenicity and reactogenicity. These findings can be relevant for the future development of our understanding of how mRNA vaccines function.

IgG antibody levels against the SARS-CoV-2 spike protein in mother-child dyads after COVID-19 vaccination

PURPOSE

We aimed to assess IgG antibodies against the SARS-CoV-2 spike protein (anti-SARS-CoV-2 S IgG) in vaccinated mothers and their infants at delivery and 2-3 months of age.

METHODS

We conducted a prospective study on mothers who received at least one dose of the COVID-19 vaccine (Pfizer-BNT162b2, Moderna mRNA-1273, or Oxford-AstraZeneca ChAdOx1-S) during pregnancy and on their infants. The baseline was at the time of delivery (n = 93), and the end of follow-up was 2 to 3 months post-partum (n = 53). Serum anti-SARS-CoV-2 S IgG titers and ACE2 binding inhibition levels were quantified by immunoassays.

RESULTS

Mothers and infants had high anti-SARS-CoV-2 S IgG titers against the B.1 lineage at birth. However, while antibody titers were maintained at 2-3 months post-partum in mothers, they decreased significantly in infants (p < 0.001). Positive and significant correlations were found between anti-SARS-CoV-2 S IgG titers and ACE2-binding inhibition levels in mothers and infants at birth and 2-3 months post-partum (r > 0.8, p < 0.001). Anti-S antibodies were also quantified for the Omicron variant at 2-3 months post-partum. The antibody titers against Omicron were significantly lower in mothers and infants than those against B.1 (p < 0.001). Again, a positive correlation was observed for Omicron between IgG titers and ACE2-binding inhibition both in mothers (r = 0.818, p < 0.001) and infants (r = 0.386, p < 0.005). Previous SARS-CoV-2 infection and COVID-19 vaccination near delivery positively impacted anti-SARS-CoV-2 S IgG levels.

CONCLUSIONS

COVID-19 mRNA vaccines induce high anti-SARS-CoV-2 S titers in pregnant women, which can inhibit the binding of ACE2 to protein S and are efficiently transferred to the fetus. However, there was a rapid decrease in antibody levels at 2 to 3 months post-partum, particularly in infants.

Modulation of innate immune response to mRNA vaccination after SARS-CoV-2 infection or sequential vaccination in humans

mRNA vaccines are likely to become widely used for the prevention of infectious diseases in the future. Nevertheless, a notable gap exists in mechanistic data, particularly concerning the potential effects of sequential mRNA immunization or preexisting immunity on the early innate immune response triggered by vaccination. In this study, healthy adults, with or without documented prior SARS-CoV-2 infection, were vaccinated with the BNT162b2/Comirnaty mRNA vaccine. Prior infection conferred significantly stronger induction of proinflammatory and type I IFN-related gene signatures, serum cytokines, and monocyte expansion after the prime vaccination. The response to the second vaccination further increased the magnitude of the early innate response in both study groups. The third vaccination did not further increase vaccine-induced inflammation. In vitro stimulation of PBMCs with TLR ligands showed no difference in cytokine responses between groups, or before or after prime vaccination, indicating absence of a trained immunity effect. We observed that levels of preexisting antigen-specific CD4 T cells, antibody, and memory B cells correlated with elements of the early innate response to the first vaccination. Our data thereby indicate that preexisting memory formed by infection may augment the innate immune activation induced by mRNA vaccines.

Impact of Prior COVID-19 Immunization and/or Prior Infection on Immune Responses and Clinical Outcomes

Cellular and humoral immunity exhibit dynamic adaptation to the mutating SARS-CoV-2 virus. It is noteworthy that immune responses differ significantly, influenced by whether a patient has received vaccination or whether there is co-occurrence of naturally acquired and vaccine-induced immunity, known as hybrid immunity. The different immune reactions, conditional on vaccination status and the viral variant involved, bear implications for inflammatory responses, patient outcomes, pathogen transmission rates, and lingering post-COVID conditions. Considering these developments, we have performed a review of recently published literature, aiming to disentangle the intricate relationships among immunological profiles, transmission, the long-term health effects post-COVID infection poses, and the resultant clinical manifestations. This investigation is directed toward understanding the variability in the longevity and potency of cellular and humoral immune responses elicited by immunization and hybrid infection.

Humoral and cellular immunity to SARS-CoV-2 following vaccination with non-mRNA vaccines in adolescent/young adults with cancer: A prospective cohort study

BACKGROUND

Data on SARS-CoV-2 vaccine responsiveness in adolescent/young adult (AYA) cancer patients are sparse. The present study assessed humoral and cellular immune responses post-vaccination in this population.

METHODS

In this prospective study, patients aged 12-30 years undergoing cancer therapy ("on therapy") and survivors ("off therapy") were recruited. Anti-receptor binding domain (RBD) protein IgG levels were measured at baseline, four weeks post-first vaccine dose (T1), and six weeks post-second dose (T2). Cellular immunity was assessed using activation-induced markers and intracellular cytokine staining in a patient subset. The primary outcome was to quantify humoral responses in both cohorts at T2 compared to baseline. Clinical predictors of log antibody titres at T2 were identified.

RESULTS

Between April-December 2022, 118 patients were recruited of median age 15.4 years. Among them, 77 (65.2 %) were in the "on therapy" group, and 77 (65.2 %) had received the BBV152 vaccine. At baseline, 108 (91.5 %) patients were seropositive for anti-RBD antibody. The log anti-RBD titre rose from baseline to T2 (p-value = 0.001) in the whole cohort; this rise was significant from baseline-T1 (p-value < 0.001), but not from T1 to T2 (p-value = 0.842). A similar pattern was seen in the "on therapy" cohort. BECOV-2 vaccine was independently associated with higher log anti-RBD titres than BBV152 (regression coefficient: 0.41; 95 % CI: 0.10-0.73; p = 0.011). Cellular immune responses were similar in the "on-" and "off therapy" groups at the three time points.

CONCLUSION

Among AYA cancer patients, a single non-mRNA vaccine dose confers robust hybrid humoral immunity with limited benefit from a second dose.

Determinants of health as predictors for differential antibody responses following SARS-CoV-2 primary and booster vaccination in an at-risk, longitudinal cohort

Post vaccine immunity following COVID-19 mRNA vaccination may be driven by extrinsic, or controllable and intrinsic, or inherent health factors. Thus, we investigated the effects of extrinsic and intrinsic on the peak antibody response following COVID-19 primary vaccination and on the trajectory of peak antibody magnitude and durability over time. Participants in a longitudinal cohort attended visits every 3 months for up to 2 years following enrollment. At baseline, participants provided information on their demographics, recreational behaviors, and comorbid health conditions which guided our model selection process. Blood samples were collected for serum processing and spike antibody testing at each visit. Cross-sectional and longitudinal models (linear-mixed effects models) were generated to assess the relationship between selected intrinsic and extrinsic health factors on peak antibody following vaccination and to determine the influence of these predictors on antibody over time. Following cross-sectional analysis, we observed higher peak antibody titers after primary vaccination in females, those who reported recreational drug use, younger age, and prior COVID-19 history. Following booster vaccination, females and Hispanics had higher peak titers after the 3rd and 4th doses, respectively. Longitudinal models demonstrated that Moderna mRNA-1273 recipients, females, and those previously vaccinated had increased peak titers over time. Moreover, drug users and half-dose Moderna mRNA-1273 recipients had higher peak antibody titers over time following the first booster, while no predictive factors significantly affected post-second booster antibody responses. Overall, both intrinsic and extrinsic health factors play a significant role in shaping humoral immunogenicity after initial vaccination and the first booster. The absence of predictive factors for second booster immunogenicity suggests a more robust and consistent immune response after the second booster vaccine administration.

The roles of lncRNAs and miRNAs in pancreatic cancer: a focus on cancer development and progression and their roles as potential biomarkers

Pancreatic ductal adenocarcinoma (PDAC) is among the most penetrative malignancies affecting humans, with mounting incidence prevalence worldwide. This cancer is usually not diagnosed in the early stages. There is also no effective therapy against PDAC, and most patients have chemo-resistance. The combination of these factors causes PDAC to have a poor prognosis, and often patients do not live longer than six months. Because of the failure of conventional therapies, the identification of key biomarkers is crucial in the early diagnosis, treatment, and prognosis of pancreatic cancer. 65% of the human genome encodes ncRNAs. There are different types of ncRNAs that are classified based on their sequence lengths and functions. They play a vital role in replication, transcription, translation, and epigenetic regulation. They also participate in some cellular processes, such as proliferation, differentiation, metabolism, and apoptosis. The roles of ncRNAs as tumor suppressors or oncogenes in the growth of tumors in a variety of tissues, including the pancreas, have been demonstrated in several studies. This study discusses the key roles of some lncRNAs and miRNAs in the growth and advancement of pancreatic carcinoma. Because they are involved not only in the premature identification, chemo-resistance and prognostication, also their roles as potential biomarkers for better management of PDAC patients.

SARS-CoV-2-infection- and vaccine-induced antibody responses are long lasting with an initial waning phase followed by a stabilization phase

It is thought that mRNA-based vaccine-induced immunity to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) wanes quickly, based mostly on short-term studies. Here, we analyzed the kinetics and durability of the humoral responses to SARS-CoV-2 infection and vaccination using >8,000 longitudinal samples collected over a 3-year period in New York City. Upon primary immunization, participants with pre-existing immunity mounted higher antibody responses faster and achieved higher steady-state antibody titers than naive individuals. Antibody kinetics were characterized by two phases: an initial rapid decay, followed by a stabilization phase with very slow decay. Booster vaccination equalized the differences in antibody concentration between participants with and without hybrid immunity, but the peak antibody titers decreased with each successive antigen exposure. Breakthrough infections increased antibodies to similar titers as an additional vaccine dose in naive individuals. Our study provides strong evidence that SARS-CoV-2 antibody responses are long lasting, with initial waning followed by stabilization.

The effect of dose-interval on antibody response to mRNA COVID-19 vaccines: a prospective cohort study

Background

Vaccination against COVID-19 is highly effective in preventing severe disease and hospitalization, but primary COVID mRNA vaccination schedules often differed from those recommended by the manufacturers due to supply chain issues. We investigated the impact of delaying the second dose on antibody responses to COVID mRNA-vaccines in a prospective cohort of health-care workers in Quebec.

Methods

We recruited participants from the McGill University Health Centre who provided serum or participant-collected dried blood samples (DBS) at 28-days, 3 months, and 6 months post-second dose and at 28-days after a third dose. IgG antibodies to SARS-CoV2 spike (S), the receptor-binding domain (RBD), nucleocapsid (N) and neutralizing antibodies to the ancestral strain were assessed by enzyme-linked immunosorbent assay (ELISA). We examined associations between long (≤89 days) versus short (<89 days) between-dose intervals and antibody response through multivariable mixed-effects models adjusted for age, sex, prior covid infection status, time since vaccine dose, and assay batch.

Findings

The cohort included 328 participants who received up to three vaccine doses (>80% Pfizer-BioNTech). Weighted averages of the serum (n=744) and DBS (n=216) cohort results from the multivariable models showed that IgG anti-S was 31% higher (95% CI: 12% to 53%) and IgG anti-RBD was 37% higher (95% CI: 14% to 65%) in the long vs. short interval participants, across all time points.

Interpretation

Our study indicates that extending the covid primary series between-dose interval beyond 89 days (approximately 3 months) provides stronger antibody responses than intervals less than 89 days. Our demonstration of a more robust antibody response with a longer between dose interval is reassuring as logistical and supply challenges are navigated in low-resource settings.

B-cell and antibody responses to SARS-CoV-2: infection, vaccination, and hybrid immunity

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in 2019 prompted scientific, medical, and biotech communities to investigate infection- and vaccine-induced immune responses in the context of this pathogen. B-cell and antibody responses are at the center of these investigations, as neutralizing antibodies (nAbs) are an important correlate of protection (COP) from infection and the primary target of SARS-CoV-2 vaccine modalities. In addition to absolute levels, nAb longevity, neutralization breadth, immunoglobulin isotype and subtype composition, and presence at mucosal sites have become important topics for scientists and health policy makers. The recent pandemic was and still is a unique setting in which to study de novo and memory B-cell (MBC) and antibody responses in the dynamic interplay of infection- and vaccine-induced immunity. It also provided an opportunity to explore new vaccine platforms, such as mRNA or adenoviral vector vaccines, in unprecedented cohort sizes. Combined with the technological advances of recent years, this situation has provided detailed mechanistic insights into the development of B-cell and antibody responses but also revealed some unexpected findings. In this review, we summarize the key findings of the last 2.5 years regarding infection- and vaccine-induced B-cell immunity, which we believe are of significant value not only in the context of SARS-CoV-2 but also for future vaccination approaches in endemic and pandemic settings.

Assessing the Impact of COVID-19 Vaccination on Preterm Birth: A Systematic Review with Meta-Analysis

During the coronavirus diseases 2019 (COVID-19) pandemic, the safety and efficacy of vaccination during pregnancy, particularly regarding the risk of preterm birth, have been a subject of concern. This systematic review aims to evaluate the impact of COVID-19 vaccination on preterm birth risk and to inform clinical practice and public health policies. Following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, a database search included PubMed, Embase, and Scopus, conducted up until October 2023. Inclusion criteria focused on studies that examined COVID-19 vaccination during pregnancy and its correlation with preterm birth, defined as a birth before 37 weeks of gestation. Six studies met these criteria, encompassing 35,612 patients. A quality assessment was performed using the Newcastle-Ottawa Scale and the Cochrane Collaboration's tool, with the risk of bias evaluated via a funnel plot analysis and an Egger's regression test. The studies demonstrated geographical diversity, mainly from Israel, Romania, and the United States, with a blend of prospective and retrospective designs. The patient cohort's mean age was 31.2 years, with common comorbidities such as gestational diabetes and obesity affecting 9.85% of the total population. The vaccination types varied across the studies, with BNT162b2 being the most used. The results indicated a low heterogeneity among the included studies, evidenced by a Cochran's Q statistic of 2.10 and an I2 statistic of 13%. The meta-analysis yielded a pooled odds ratio (OR) for a preterm birth risk post-vaccination of approximately 1.03 (95% CI: 0.82-1.30), suggesting no significant increase in preterm birth risk was associated with COVID-19 vaccination. Notable findings included a low preterm birth rate (as low as 0.6% and up to 6.1%) with minimal differences in neonatal outcomes, such as birth weight and APGAR (appearance, pulse, grimace, activity, and respiration) scores between vaccinated and unvaccinated groups. This study concludes that a COVID-19 vaccination during pregnancy does not significantly increase the risk of preterm birth. These findings are crucial for reassuring healthcare providers and pregnant women about the safety of COVID-19 vaccines and supporting their use in public health strategies during the pandemic.

The post-COVID-19 population has a high prevalence of cross-reactive antibodies to spikes from all Orthocoronavirinae genera

IMPORTANCE

As demonstrated by severe acute respiratory syndrome coronavirus 2, coronaviruses pose a significant pandemic threat. Here, we show that coronavirus disease 2019 mRNA vaccination can induce significant levels of cross-reactive antibodies against diverse coronavirus spike proteins. While these antibodies are binding antibodies that likely have little neutralization capacity and while their contribution to cross-protection is unclear, it is possible that they may play a role in protection from progression to severe disease with novel coronaviruses.

Impact on the time elapsed since SARS-CoV-2 infection, vaccination history, and number of doses, on protection against reinfection

SARS-CoV-2 reinfections have been frequent, even among those vaccinated. The aim of this study is to know if hybrid immunity (infection + vaccination) is affected by the moment of vaccination and number of doses received. We conducted a retrospective study in 746 patients with a history of COVID-19 reinfection and recovered the dates of infection and reinfection and vaccination status (date and number of doses). To assess differences in the time to reinfection(tRI) between unvaccinated, vaccinated before 6 months, and later; and comparing one, two or three doses (incomplete, complete and booster regime) we performed the log-rank test of the cumulative incidence calculated as 1 minus the Kaplan-Meier estimator. Also, an adjusted Cox-regression was performed to evaluate the risk of reinfection in all groups. The tRI was significantly higher in those vaccinated vs. non-vaccinated (p < 0.001). However, an early incomplete regime protects similar time than not receiving a vaccine. Vaccination before 6 months after infection showed a lower tRI compared to those vaccinated later with the same regime (adj-p < 0.001). Actually, early vaccination with complete and booster regimes provided lower length of protection compared to vaccinating later with incomplete and complete regime, respectively. Vaccination with complete and booster regimes significantly increases the tRI (adj-p < 0.001). Vaccination increases the time it takes for a person to become reinfected with SARS-CoV-2. Increasing the time from infection to vaccination increases the time in which a person could be reinfected and reduces the risk of reinfection, especially in complete and booster regimes. Those results emphasize the role of vaccines and boosters during the pandemic and can guide strategies on future vaccination policy.

Magnitude and Durability of the Antibody Response to mRNA-Based Vaccination Among SARS-CoV-2 Seronegative and Seropositive Health Care Personnel

Few studies have described changes in SARS-CoV-2 antibody levels in response to infection and vaccination at frequent intervals and over extended follow-up periods. The purpose of this study was to assess changes in SARS-CoV-2-specific antibody responses among a prospective cohort of health care personnel over 18 months with up to 22 samples per person. Antibody levels and live virus neutralization were measured before and after mRNA-based vaccination with results stratified by (1) SARS-CoV-2 infection status prior to initial vaccination and (2) SARS-CoV-2 infection at any point during follow-up. We found that the antibody response to the first dose was almost 2-fold higher in individuals who were seropositive prior to vaccination, although neutralization titers were more variable. The antibody response induced by vaccination appeared to wane over time but generally persisted for 8 to 9 months, and those who were infected at any point during the study had slightly higher antibody levels over time vs those who remained uninfected. These findings underscore the need to account for SARS-CoV-2 natural infection as a modifier of vaccine responses, and they highlight the importance of frequent testing of longitudinal antibody titers over time. Together, our results provide a clearer understanding of the trajectories of antibody response among vaccinated individuals with and without prior SARS-CoV-2 infection.

Immunogenicity and adverse events of the COVID-19 vaccines in healthy and individuals with autoimmune diseases in an Iranian population

Introduction: Recent studies have proposed various COVID-19 vaccines to control the disease and protect susceptible individuals. However, immunogenicity and safety of COVID-19 vaccines in various populations are not well identified yet. Therefore, this study aimed to elucidate the efficacy and safety of the BBIBP-CorV (Sinopharm) and ChAdOx1 nCoV-19 (Oxford-AstraZeneca) vaccines in healthy subjects and patients with autoimmune diseases.Methods: Study population included 121 healthy subjects and 100 patients with autoimmune diseases. Immunization was performed based on the national vaccination protocols. Of the 221 volunteers, 201 subjects received Sinopharm and 20 cases were vaccinated with Oxford-AstraZeneca. During a 1-year follow-up, the immunogenicity was measured by ELISA before primary vaccination and 1 to 3 months after secondary immunization. Side effects were studied before entering the study and 1 week after the second dose.Results: Vaccination had a positive impact on the induction of immunogenic response (p < .0001). The rates of seropositive vaccine responses were 80% and 75% in subjects vaccinated with the Sinopharm and Oxford-AstraZeneca, respectively. The neutralizing antibody values were significantly higher in subjects with autoimmune diseases than those without autoimmunity (p < .05). The rate of adverse events were 38% and 42% in subjects vaccinated with the Sinopharm and Oxford-AstraZeneca, respectively. The rates of immunogenic responses induced with the Sinopharm and Oxford-AstraZeneca were, respectively, 76% and 81.5% in seropositive subjects, while they were 63.8% and 79.1% in seronegative subjects vaccinated with the Sinopharm and Oxford-AstraZeneca, respectively. Individuals previously infected with SARS-CoV-2 showed a significant reduction in the value of SARS-CoV-2 neutralizing antibodies compared with seronegative subjects (p < .01-.05). Seropositive individuals vaccinated with the Sinopharm had significantly higher the percentages of vaccine-related adverse events than seronegative persons (p < .05). There was no significant difference between seronegative and seropositive individuals vaccinated with the Oxford-AstraZeneca.Conclusion: Our findings revealed that the Sinopharm and Oxford-AstraZeneca vaccines are effective in the production of neutralizing antibodies in healthy subjects and patients with autoimmune disorders undergoing immunosuppressive therapies without considerable reactogenicity.

What can neutralizing antibodies tell us about the quality of immunity in COVID-19 convalescents and vaccinees?

During the SARS-CoV-2 pandemic, the lack of standardized measurements of the immune response after vaccination or recovery from COVID-19 resulted in incomparable results and hindered correlation establishment. Prioritizing reliable and standardized methods to monitor pathogen-specific immunity is crucial, not only during the COVID-19 pandemic but also for future outbreaks. During our study of the humoral immune response, we used a SARS-CoV-2 wild-type neutralization assay, ensuring the measurement of the immune response directed to all SARS-CoV-2 antigens in their proper conformation. A head-to-head comparison of the neutralizing antibody (NAb) responses elicited by four vaccines used in Europe during 2021 (BNT162b2, mRNA-1273, ChAdOx nCoV-19, and Ad26.COV2.S) and their comparison to NAb responses in convalescents showed that while the amount was comparable, NAbs induced by natural infection were of higher quality. Namely, NAbs produced by disease were better activators of the complement system than NAbs induced by vaccination. Furthermore, the contribution of spike protein-specific IgGs to the SARS-CoV-2 neutralization was lower in convalescents compared to vaccinees, indicating that those who recovered from COVID-19 were armed with antibodies of additional specificities and/or classes that contributed to virus neutralization. These findings suggest that a higher stringency of public policy measures targeting individuals who have recovered from COVID-19, in comparison to those who have been vaccinated, may not have been fully justified.

Sociodemographic factors affecting not receiving COVID-19 vaccine in Japan among people who originally intended to vaccinate: a prospective cohort study

Objective

Vaccine hesitancy is a major issue for acquiring herd immunity. However, some individuals may go unvaccinated owing to inhibitory factors other than vaccine hesitancy. If there is even a small number of such people, support is needed for equitable vaccine distribution and acquiring herd immunity. We investigated sociodemographic factors that affected not undergoing COVID-19 vaccination in Japan among individuals who had strong intention to vaccinate before beginning the vaccination.

Methods

We conducted this prospective cohort study on workers aged 20-65 years from December 2020 (baseline), to December 2021 using a self-administered questionnaire survey. There were 27,036 participants at baseline and 18,560 at follow-up. We included 6,955 participants who answered yes to this question at baseline: "Would you like to receive a COVID-19 vaccine as soon as it becomes available?" We applied multilevel logistic regression analyses to examine the association between sociodemographic factors and being unvaccinated at follow-up.

Results

In all, 289 participants (4.2%) went unvaccinated. The odds ratios (ORs) for being unvaccinated were significantly higher for participants aged 30-39 and 40-49 than those aged 60-65 years. Being divorced, widowed, or single, having low income, and having COVID-19 infection experience also had higher ORs.

Discussion

We found that some participants who initially had strong intention to vaccinate may have gone unvaccinated owing to vaccine side effects and the financial impact of absenteeism due to side effects. It is necessary to provide information repeatedly about the need for vaccination as well as social support to ensure that those who intend to vaccinate are able to do so when aiming for acquiring herd immunity through vaccination against COVID-19 as well as other potential infection pandemics in the future.

SARS-CoV-2 infection-induced immunity reduces rates of reinfection and hospitalization caused by the Delta or Omicron variants

During a pandemic, effective vaccines are typically in short supply, particularly at onset intervals when the wave is accelerating. We conducted an observational, retrospective analysis of aggregated data from all patients who tested positive for SARS-CoV-2 during the waves caused by the Delta and Omicron variants, stratified based on their known previous infection and vaccination status, throughout the University of Texas Medical Branch (UTMB) network. Next, the immunity statuses within each medical parameter were compared to naïve individuals for the effective decrease of occurrence. Lastly, we conducted studies using mice and pre-pandemic human samples for IgG responses to viral nucleocapsid compared to spike protein toward showing a functional component supportive of the medical data results in relation to the immunity types. During the Delta and Omicron waves, both infection-induced and hybrid immunities were associated with a trend of equal or greater decrease of occurrence than vaccine-induced immunity in hospitalizations, intensive care unit admissions, and deaths in comparison to those without pre-existing immunity, with hybrid immunity often trending with the greatest decrease. Compared to individuals without pre-existing immunity, those vaccinated against SARS-CoV-2 had a significantly reduced incidence of COVID-19, as well as all subsequent medical parameters. Though vaccination best reduces health risks associated with initial infection toward acquiring immunity, our findings suggest infection-induced immunity is as or more effective than vaccination in reducing the severity of reinfection from the Delta or Omicron variants, which should inform public health response at pandemic onset, particularly when triaging towards the allotment of in-demand vaccinations.

The effect of the third dose of the BNT162b2 vaccine on anti-SARS-CoV-2 spike antibody levels in healthcare workers with and without COVID-19 infection

AIM

A third (booster) dose of the anti-SARS-CoV-2 vaccine became necessary due to the observed decrease in anti-SARS-CoV-2S antibody levels over time, new mutations, and low global vaccination rates. In this study, anti-SARS-CoV-2S antibody levels were measured (ECLIA assay) in 50 healthcare workers with and without a history of COVID-19 infection to determine the humoral immune response to the third dose of the BNT162b2 vaccine.

METHODS

Antibody levels were determined in the blood serum, and blood was sampled for analysis 20-40 days after the administration of the booster dose.

RESULTS

A greater increase in anti-SARS-CoV-2S antibody titers was noted in persons without a history of infection, but antibody levels continued to be higher in previously infected individuals when the results were adjusted for age, gender, BMI, type of work, and presence of comorbidities.

CONCLUSION

The results of this study can be used to improve the vaccination strategy for the general population.KEY MESSAGESThree doses of the vaccine BNT162b2 strongly stimulate the immune system to produce anti-SARS-CoV-2s antibodies, especially in people with a previous infection COVID-19.Age, gender, and BMI may be associated with different humoral immune response to the BNT162b2 vaccine.

Immune responses of lung transplant recipients against SARS-CoV-2 and common respiratory coronaviruses: Evidence for pre-existing cross-reactive immunity

Humoral and cellular immune responses to SARS-CoV-2 and other coronaviruses in lung transplant recipients are unknown. We measured antibodies and T cell responses against the SARS-CoV-2 spike S2 and nucleocapsid antigens and spike antigens from common respiratory coronaviruses (229E, NL63, OC43, and HKU1) after vaccination or infection of LTxRs. 148 LTxRs from single center were included in this study: 98 after vaccination and 50 following SARS-CoV-2 infection. Antibodies were quantified by enzyme-linked immunosorbent assay. The frequency of T cells secreting IL2, IL4, IL10, IL17, TNFα, and IFNγ were enumerated by enzyme-linked immunospot assay. Our results have shown the development of antibodies to SARS-CoV-2 spike protein in infected LTxRs (39/50) and vaccinated LTxRs (52/98). Vaccinated LTxRs had higher number of T cells producing TNFα but less cells producing IFNγ than infected LTxRs in response to the nucleocapsid antigen and other coronavirus spike antigens. We didn't find correlation between the development of antibodies and cellular immune responses against the SARS-CoV-2 spike protein after vaccination. Instead, LTxRs have pre-existing cellular immunity to common respiratory coronaviruses, leading to cross-reactive immunity against SARS-CoV-2 which likely will provide protection against SARS-Cov-2 infection.

Unraveling the association between vaccine attitude, vaccine conspiracies and self-reported side effects following COVID-19 vaccination among nurses and physicians in Jordan

Background

The negative impact of vaccine conspiracies is linked with negative health behavior. The aim of the current study was to examine the association between attitudes toward booster COVID-19, influenza, and monkeypox (mpox) vaccinations with post-COVID-19 vaccine side effects, vaccine conspiracies, and attitude towards mandatory vaccination among nurses and physicians in Jordan.

Methods

A structured closed-ended questionnaire was used to collect data on demographics, COVID-19 history, COVID-19 vaccine type and doses received, self-reported side effects post-COVID-19 vaccination, acceptance of booster COVID-19, seasonal influenza, and mpox vaccinations, attitudes towards mandatory vaccination, and beliefs in vaccine conspiracies.

Results

The study sample comprised a total of 341 participants. Acceptance of yearly booster COVID-19 vaccination was expressed by 46.6% of the sample, while 73.3% accepted seasonal influenza vaccination, and only 37.0% accepted mpox vaccination. A higher frequency of self-reported side effects following the first COVID-19 vaccine dose was associated with embrace of vaccine conspiracies and vaccine type. For the second vaccine dose, a higher frequency of self-reported side effects was associated with the embrace of vaccine conspiracies, older age, and affiliation to private sector. In multinomial logistic regression analyses, the lower embrace of vaccine conspiracies was associated with lower odds of reporting side effects post-COVID-19 vaccination. The lower embrace of vaccine conspiracies and favorable attitude towards mandatory vaccination were associated with the willingness to get COVID-19, influenza, and mpox vaccinations.

Conclusion

The study findings highlighted the negative impact of embracing vaccine conspiracies on health-seeking behavior among nurses and physicians. The findings indicated that the willingness to get vaccinated was associated with lower endorsement of vaccine conspiracies. Additionally, the lower embrace of vaccine conspiracies was associated with a lower frequency of self-reported side effects following COVID-19 vaccination. These results emphasize the importance of addressing vaccine misinformation and promoting accurate information to ensure optimal vaccine uptake and public health outcomes.

BNT162b2 Booster Dose Elicits a Robust Antibody Response in Subjects with Abdominal Obesity and Previous SARS-CoV-2 Infection

Little is known about the long-term durability of the induced immune response in subjects with obesity, particularly in those with an abdominal distribution of adipose tissue. We evaluated SARS-CoV-2-specific antibody responses after BNT162b2 vaccine booster dose, comparing individuals with and without abdominal obesity (AO), discerning between individuals previously infected or not. IgG-TrimericS were measured in 511 subjects at baseline, on the 21st day after vaccine dose 1, and at 1, 3, 6, and 9 months from dose 2, and at 1 and 3 months following the booster dose. To detect SARS-CoV-2 infection, nucleocapsid antibodies were measured at baseline and at the end of the study. Multivariable linear regression evaluated the three-month difference in the absolute variation in IgG-TrimericS levels from booster dose, showing AO and SARS-CoV-2 infection status interactions (p = 0.016). Regardless of possible confounding factors and IgG-TrimericS levels at the booster dose, AO is associated with a higher absolute change in IgG-TrimericS in prior infected individuals (p = 0.0125). In the same regression model, no interaction is highlighted using BMI (p = 0.418). The robust response in the development of antibodies after booster dose, observed in people with AO and previous infection, may support the recommendations to administer a booster dose in this population group.

Impact of sex and age on vaccine-related side effects and their progression after booster mRNA COVID-19 vaccine

In mRNA COVID-19 vaccination, side effects after the first and second dose have been well reported. However, studies about side effects after booster vaccine are sparse. 272 healthcare workers who received the third mRNA COVID-19 vaccine were recruited, and impact of sex, age, and symptoms on the side effect progression was statistically analyzed. Females and younger adults had a higher frequencies of general fatigue, headache, joint pain, chills and axillary pain compared to males and elderly adults, respectively. In longitudinal analysis, prolonged time to recovery from side effects was found among females and younger adults. Finally, between the third and second dose vaccinations, 52% of subjects had a longer duration of side effects following the third vaccine compared to the second, and joint pain was the culprit symptom related to the prolonged duration of side effects. Following the second vaccine dose, 25% of subjects had a longer duration of side effects and asthma and ear fullness, which exacerbated the underlying allergic condition, and COVID arm symptom were the culprit symptoms. These highlight the impact of sex, age, and culprit symptoms on the progress of side effects following the booster mRNA COVID-19 vaccine.

Respiratory mucosal immune memory to SARS-CoV-2 after infection and vaccination

Respiratory mucosal immunity induced by vaccination is vital for protection from coronavirus infection in animal models. In humans, the capacity of peripheral vaccination to generate sustained immunity in the lung mucosa, and how this is influenced by prior SARS-CoV-2 infection, is unknown. Here we show using bronchoalveolar lavage samples that donors with history of both infection and vaccination have more airway mucosal SARS-CoV-2 antibodies and memory B cells than those only vaccinated. Infection also induces populations of airway spike-specific memory CD4+ and CD8+ T cells that are not expanded by vaccination alone. Airway mucosal T cells induced by infection have a distinct hierarchy of antigen specificity compared to the periphery. Spike-specific T cells persist in the lung mucosa for 7 months after the last immunising event. Thus, peripheral vaccination alone does not appear to induce durable lung mucosal immunity against SARS-CoV-2, supporting an argument for the need for vaccines targeting the airways.

Multimodal single-cell datasets characterize antigen-specific CD8+ T cells across SARS-CoV-2 vaccination and infection

The immune response to SARS-CoV-2 antigen after infection or vaccination is defined by the durable production of antibodies and T cells. Population-based monitoring typically focuses on antibody titer, but there is a need for improved characterization and quantification of T cell responses. Here, we used multimodal sequencing technologies to perform a longitudinal analysis of circulating human leukocytes collected before and after immunization with the mRNA vaccine BNT162b2. Our data indicated distinct subpopulations of CD8+ T cells, which reliably appeared 28 days after prime vaccination. Using a suite of cross-modality integration tools, we defined their transcriptome, accessible chromatin landscape and immunophenotype, and we identified unique biomarkers within each modality. We further showed that this vaccine-induced population was SARS-CoV-2 antigen-specific and capable of rapid clonal expansion. Moreover, we identified these CD8+ T cell populations in scRNA-seq datasets from COVID-19 patients and found that their relative frequency and differentiation outcomes were predictive of subsequent clinical outcomes.

The Antibodies' Response to SARS-CoV-2 Vaccination: 1-Year Follow Up

The use of vaccines has allowed the containment of coronavirus disease 2019 (COVID-19) at a global level. The present work aims to add data on vaccination by evaluating the level of neutralizing antibodies in individuals who have received a three-vaccination series. For this purpose, we ran a surveillance program directed at measuring the level of IgG Abs against the Receptor Binding Domain (RBD) and surrogate virus neutralizing Ab (sVNT) anti-SARS-CoV-2 in the serum of individuals undergoing vaccination. This study was performed on employees from the University of Rome Tor Vergata and healthcare workers from the University Hospital who received the Vaxzevria vaccine (n = 56) and Comirnaty vaccine (n = 113), respectively. After the second dose, an increase in both RBD and sVNT Ab values was registered. In individuals who received the Comirnaty vaccine, the antibody titer was about one order of magnitude higher after 6 months from the first dose. All participants in this study received the Comirnaty vaccine as the third dose, which boosted the antibody response. Five months after the third dose, nearly one year from the first injection, the antibody level was >1000 BAU/mL (binding antibody units/mL). According to the values reported in the literature conferring protection against SARS-CoV-2 infection, our data indicate that individuals undergoing three vaccine doses present a low risk of infection.

Comparison between Neutralization Capacity of Antibodies Elicited by COVID-19 Natural Infection and Vaccination in Indonesia: A Prospective Cohort

BACKGROUND

To fight the COVID-19 pandemic, immunity against SARS-CoV-2 should be achieved not only through natural infection but also by vaccination. The effect of COVID-19 vaccination on previously infected persons is debatable.

METHODS

A prospective cohort was undergone to collect sera from unvaccinated survivors and vaccinated persons-with and without COVID-19 pre-infection. The sera were analyzed for the anti-receptor binding domain (RBD) titers by ELISA and for the capacity to neutralize the pseudovirus of the Wuhan-Hu-1 strain by luciferase assays.

RESULTS

Neither the antibody titers nor the neutralization capacity was significantly different between the three groups. However, the correlation between the antibody titers and the percentage of viral neutralization derived from sera of unvaccinated survivors was higher than that from vaccinated persons with pre-infection and vaccinated naïve individuals (Spearman correlation coefficient (r) = -0.8558; 95% CI, -0.9259 to -0.7288), p < 0.0001 vs. -0.7855; 95% CI, -0.8877 to -0.6096, p < 0.0001 and -0.581; 95% CI, -0.7679 to -0.3028, p = 0.0002, respectively), indicating the capacity to neutralize the virus is most superior by infection alone.

CONCLUSIONS

Vaccines induce anti-RBD titers as high as the natural infection with lower neutralization capacity, and it does not boost immunity in pre-infected persons.

COVID-19 Serological Study in Non-infected Vaccinated Subjects: Differences among Age, Sex, and Vaccine Brand

OBJECTIVE

To evaluate IgG antibody levels against SARS-CoV-2 in non-infected vaccinated subjects among vaccine brand, sex, and age.

METHODS

Abbott's AdviseDx SARS-CoV-2 IgG II immunoassay was used to measure IgG levels within 6-9 months after the second dose vaccination; level >50 AU/mL was classified as a positive test.

RESULTS

Data of 183 non-infected vaccinated subjects was analyzed according to the vaccine brand, time after second vaccination, sex, and age. Bivariate analysis showed that receiving the Moderna brand vaccine, being female, and younger were associated with higher antibody levels, p<.001. Conversely, no differences were observed between the IgG antibody levels against SARS-CoV-2 and time after second vaccination (6-7 months as compared to 8-9 months), p=.49.

CONCLUSION

After six to nine months post-vaccination, receiving the Moderna vaccine, being female, and being younger were significantly associated to higher IgG antibody levels to SARS-CoV-2 in non-infected vaccinated subjects.

Effect of COVID-19 Vaccination on the Levels of SARS-CoV-2 Neutralizing Antibodies in COVID-19 Naive, Hybrid, and Breakthrough SARS-CoV-2 Recovered Indian Individuals

Introduction  Vaccination has shown to be protective against severe coronavirus disease 2019 by various studies. However, the vaccine efficacy was demonstrated to be less against the emerging variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Both vaccine- and infection-induced immunity against SARS-CoV-2 may prevent reinfection and severity. Our study aims to assess and compare the humoral response in heterogeneous population based on infection and vaccination status along with hybrid immunity. Methods  A retrospective, observational study of 2,545 adults was conducted. The study groups comprised of group I ( n  = 309) naive with a single dose of vaccination, group II ( n  = 357) infected and unvaccinated, group III ( n  = 590) completely vaccinated with two doses of vaccine, group IV ( n  = 70) booster dose, group V ( n  = 602) with hybrid immunity (pre-vaccination infection), and group VI ( n  = 617) with breakthrough infection (post-vaccination infection). Data pertaining to demographic details, clinical presentations, reverse transcription-polymerase chain reaction, anti-SARS-CoV-2 total antibodies immunoglobulin G (IgG), neutralizing antibodies by anti SARS-CoV-2 sVNT (surrogate virus neutralization test), S1/S2IgG, S-RBD (receptor-binding domain), and ChAdOx1-nCov-19 (Covishield) vaccination were retrieved from electronic health records. Results  The mean levels of neutralizing antibodies of group V were S1/S2, RBD (10.5/14.3 times), and sVNT (84.44%) and group VI had S1/S2, RBD (11.4/11.8 times), and sVNT (78.07%) when compared to group III. We also observed a statistically significant higher immune response in group V and VI than group I and II. A higher percentage (18.2%) of group II individuals had severe disease when compared to group V and VI (6.5/10.8%). Conclusion  A single dose of ChAdOx1 vaccine gives robust antibody responses in previously infected individuals and may confer long-term hybrid immunity following booster vaccination.

Prior cycles of anti-CD20 antibodies affect antibody responses after repeated SARS-CoV-2 mRNA vaccination

BACKGROUNDWhile B cell depletion is associated with attenuated antibody responses to SARS-CoV-2 mRNA vaccination, responses vary among individuals. Thus, elucidating the factors that affect immune responses after repeated vaccination is an important clinical need.METHODSWe evaluated the quality and magnitude of the T cell, B cell, antibody, and cytokine responses to a third dose of BNT162b2 or mRNA-1273 mRNA vaccine in patients with B cell depletion.RESULTSIn contrast with control individuals (n = 10), most patients on anti-CD20 therapy (n = 48) did not demonstrate an increase in spike-specific B cells or antibodies after a third dose of vaccine. A third vaccine elicited significantly increased frequencies of spike-specific non-naive T cells. A small subset of B cell-depleted individuals effectively produced spike-specific antibodies, and logistic regression models identified time since last anti-CD20 treatment and lower cumulative exposure to anti-CD20 mAbs as predictors of those having a serologic response. B cell-depleted patients who mounted an antibody response to 3 vaccine doses had persistent humoral immunity 6 months later.CONCLUSIONThese results demonstrate that serial vaccination strategies can be effective for a subset of B cell-depleted patients.FUNDINGThe NIH (R25 NS079193, P01 AI073748, U24 AI11867, R01 AI22220, UM 1HG009390, P01 AI039671, P50 CA121974, R01 CA227473, U01CA260507, 75N93019C00065, K24 AG042489), NIH HIPC Consortium (U19 AI089992), the National Multiple Sclerosis Society (CA 1061-A-18, RG-1802-30153), the Nancy Taylor Foundation for Chronic Diseases, Erase MS, and the Claude D. Pepper Older Americans Independence Center at Yale (P30 AG21342).

Breakthrough infections with SARS-CoV-2 omicron efficiently boost antibodies from previous BNT162b2 vaccinations

Objective

To investigate whether SARS-CoV-2 omicron breakthrough infection in individuals after three doses of wildtype-based BNT162b2 increases antibody levels measured by a commercially available wildtype-based immunoassay.

Methods

16 of 21 individuals in a BNT162b2 vaccination cohort (recruited 129 [129-135] days after dose 3) experienced a breakthrough infection (BTI) between March and September 2022. Antibodies to the receptor binding domain (RBP) of the spike protein (Anti-S) were quantified using the wildtype-based Elecsys SARS-CoV-2 S assay (Roche). Antibody responses of triple vaccinated BTI cases were compared to triple vaccinated individuals without breakthrough infection and to 16 matched individuals after primary omicron infection.

Results

In the 16 individuals with primary Omicron infection, the anti-S assay returned only very low results (2.25 [0.61-5.80] U/mL). However, in individuals with BTI, Anti-S levels rose from 7,135 [5,870-17,470] U/mL to 21,705 (7,750-46,137.5) U/mL. At the same time, Anti-S concentrations decreased from 9,120 [7,480-13,480] U/mL to 3,830 (2,390-4,220) U/mL in those 5 of 21 vaccinated only.

Conclusions

Our data suggest that breakthrough infection with omicron can efficiently boost wild-type antibodies in individuals vaccinated with wild-type BNT162b2.

Adverse events following immunisation (AEFI) of COVISHIELD vaccination among healthcare workers in Ghana

OBJECTIVE

To describe the incidence of adverse events following immunisation (AEFI) and determine the factors that affect the onset and duration of AEFI after COVISHIELD vaccination among healthcare workers.

DESIGN

Prospective cohort study.

SETTING

Tertiary healthcare, Korle-Bu, Ghana.

PARTICIPANT

Three thousand and twenty-two healthcare workers at least 18 years of age were followed up for 2 months after receiving two doses of the COVISHIELD vaccine.

PRIMARY OUTCOME

The occurrence of the AEFI was identified by self-reporting to the AEFI team members.

RESULTS

A total of 3022 healthcare workers had at least one AEFI (incidence rate of 706.0 (95% CI 676.8 to 736.1) per 1000 doses) with an incidence rate of 703.0 (95% CI 673.0 to 732.0) per 1000 doses for non-serious AEFI and an incidence rate of 3.3 (95% CI 1.6 to 6.1) per 1000 doses for serious AEFI. The most commonly reported systemic adverse events were headache (48.6%), fever (28.5%), weakness (18.4%) and body pains (17.9%). The estimated median time to onset of the AEFI following the first-dose vaccination was 19 hours and the median AEFI duration was 40 hours or 2 days. Delayed-onset AEFI occurred in 0.3% after first dose and 0.1% after second dose. Age, sex, previous SARS-CoV-2 infection, history of allergies and comorbidity were not significantly associated with the onset and duration of AEFI. However, participants who used paracetamol seemed to be significantly protected (HR 0.15; 95% CI 0.14, 0.17) from having a long duration of AEFI.

CONCLUSION

The results of our study indicate a high incidence of non-serious AEFI and the rare occurrence of serious AEFI after COVISHIELD vaccination in healthcare workers. The rate of AEFI was higher after the first dose than after the second dose. Sex, age, previous SARS-CoV-2 infection, allergies and comorbidity were not significantly associated with the onset and duration of AEFI.

Persistence of Anti-S1 IgG against SARS-CoV-2 Eight Months after the Booster Dose of Vaccine in Naive and Previously Infected Healthcare Workers

Our aim was to evaluate the immune response of healthcare workers included in the RIPOVAC study, after receiving a booster dose (third dose), in terms of intensity and persistence of induced antibodies. In the second phase of the RIPOVAC study, between December 2021 and January 2022, eight months after the second dose, 389 voluntary, immunocompetent, non-pregnant healthcare workers received a booster dose of SARS-CoV-2 vaccine, and a serum sample was obtained. Two groups of patients were established: with and without previous SARS-CoV-2 infection. In order to quantify anti-S1 IgG (AU/mL) we used CMIA (Abbott). All of the health workers were anti-S IgG positive 8 months after receiving the booster dose of the vaccine, with a mean of 17,040 AU/mL. In 53 patients without previous infection, antibody levels increased by a mean of 10,762 AU/mL. This figure is seven times higher than the one produced after the second dose (1506 AU/mL). The booster dose produces a robust elevation of the antibody level, which persists at 8 months, with levels significantly higher than those reached after the second dose, which allow one to predict a persistence of more than one year. The study demonstrates the efficacy of the booster dose of anti-SARS-CoV-2 vaccines.

Comparative Assessment of the Kinetics of Cellular and Humoral Immune Responses to COVID-19 Vaccination in Cancer Patients

OBJECTIVE

The kinetics of immune responses to various SARS-CoV-2 vaccines in cancer patients were investigated.

METHODS

In total, 57 cancer patients who received BNT162b2-RNA or BBIBP-CorV vaccines were enrolled. Cellular and humoral immunity were assessed at three-time points, before the first vaccine dose and 14-21 days after the first and second doses. Chemiluminescent microparticle immunoassay was used to evaluate SARS-CoV-2 anti-spike IgG response, and QuantiFERON^® SARS-CoV-2 kit assessed T-cell response.

RESULTS

Data showed that cancer patients' CD4⁺ and CD8⁺ T cell-median IFN-γ secretion of SARS-CoV-2 antigens increased after the first and second vaccine doses (p = 0.027 and p = 0.042). BNT162b2 vaccinees had significantly higher IFN-γ levels to CD4⁺ and CD8⁺ T cell epitopes than BBIBP-CorV vaccinees (p = 0.028). There was a positive correlation between IgG antibody titer and T cell response regardless of vaccine type (p < 0.05).

CONCLUSIONS

This study is one of the first to investigate cellular and humoral immune responses to SARS-CoV-2 immunization in cancer patients on active therapy after each vaccine dose. COVID-19 immunizations helped cancer patients develop an effective immune response. Understanding the cellular and humoral immune response to COVID-19 in cancer patients undergoing active treatment is necessary to improve vaccines and avoid future SARS pandemics.

Immediate adverse reactions following COVID-19 vaccination among 16-65-year-old Danish citizens

INTRODUCTION

There is sparse knowledge of immediate adverse reactions following COVID-19 vaccination.

OBJECTIVE

This study aimed to estimate the frequency and number of immediate adverse reactions following COVID-19 vaccination in a Danish population.

METHODS

The study used data from the Danish population-based cohort study BiCoVac. The frequencies of 20 self-reported adverse reactions were estimated for each vaccine dose stratified by sex, age, and vaccine type. Also, the distributions of number of adverse reactions following each dose were estimated stratified by sex, age, vaccine type, and prior COVID-19 infection.

RESULTS

A total of 889,503 citizens were invited and 171,008 (19 %) vaccinated individuals were included in the analysis. The most frequently reported adverse reaction following the first dose of COVID-19 vaccine was redness and/or pain at the injection site (20 %) while following the second and third dose, tiredness was the most frequently reported adverse reaction (22 % and 14 %, respectively). Individuals aged 26-35 years, females, and those with a prior COVID-19 infection were more likely to report adverse reactions compared with older individuals, males, and those with no prior COVID-19 infection, respectively. Following the first dose, individuals vaccinated with ChAdOx1-2 (AstraZeneca) reported more adverse reactions compared with individuals vaccinated with other vaccine types. Individuals vaccinated with mRNA-1273 (Moderna) reported more adverse reactions following the second and third dose compared with individuals vaccinated with BNT162b2 (Pfizer-BioNTech).

CONCLUSION

The frequency of immediate adverse reactions was highest among females and younger persons, however, most of the Danish citizens did not experience immediate adverse reactions following COVID-19 vaccination.

Antibody level dynamics until after the third dose of COVID-19 vaccination

The antibody titers of volunteers, including elderly people, were investigated after the second dose of the BNT162b2 vaccine (Pfizer-BioNTech) as an mRNA vaccine against the coronavirus disease 2019 (COVID-19). Serum samples were collected from 105 volunteers (44 healthcare workers and 61 elderly people) 7-14 days after the second vaccine dose, and antibody titers were measured. The antibody titers of study participants in their 20s were significantly higher than those of other age groups. Furthermore, the antibody titers of participants aged <60 years were significantly higher than those of participants aged ≥60 years. Serum samples were repeatedly collected from 44 healthcare workers until after the third vaccine dose. Eight months after the second round of vaccination, the antibody titer levels decreased to the same level as that before the second vaccine dose. After the third booster vaccination, the antibody titer recovered to the same level as that after the second dose. Neutralizing activities were also investigated at four time points before and after the second vaccine dose. The antibody titers and neutralizing activity were positively correlated. Therefore, neutralizing activity can be predicted by measuring the antibody titer. In conclusion, the antibody titers in the elderly population were significantly lower than those in the younger population. Although the antibody titers increased following vaccination, their levels showed a decline after several months, returning to the same level as that after a single dose of mRNA vaccination. The antibody titer levels recovered after the third dose of vaccination, which had already been administered in Japan. Routine administration of vaccine should be considered in the future.

Demographic, social, and behavioral correlates of SARS-CoV-2 seropositivity in a representative, population-based study of Minnesota residents

BACKGROUND

Monitoring COVID-19 infection risk in the general population is a public health priority. Few studies have measured seropositivity using representative, probability samples. The present study measured seropositivity in a representative population of Minnesota residents prior to vaccines and assess the characteristics, behaviors, and beliefs of the population at the outset of the pandemic and their association with subsequent infection.

METHODS

Participants in the Minnesota COVID-19 Antibody Study (MCAS) were recruited from residents of Minnesota who participated in the COVID-19 Household Impact Survey (CIS), a population-based survey that collected data on physical health, mental health, and economic security information between April 20 and June 8 of 2020. This was followed by collection of antibody test results between December 29, 2020 and February 26, 2021. Demographic, behavioral, and attitudinal exposures were assessed for association with the outcome of interest, SARS-CoV-2 seroprevalence, using univariate and multivariate logistic regression.

RESULTS

Of the 907 potential participants from the CIS, 585 respondents then consented to participate in the antibody testing (64.4% consent rate). Of these, results from 537 test kits were included in the final analytic sample, and 51 participants (9.5%) were seropositive. The overall weighted seroprevalence was calculated to be 11.81% (95% CI, 7.30%-16.32%) at of the time of test collection. In adjusted multivariate logistic regression models, significant associations between seroprevalence and the following were observed; being from 23-64 and 65+ age groups were both associated with higher odds of COVID-19 seropositivity compared to the 18-22 age group (17.8 [1.2-260.1] and 24.7 [1.5-404.4] respectively). When compared to a less than $30k annual income reference group, all higher income groups had significantly lower odds of seropositivity. Reporting practicing a number of 10 (median reported value in sample) or more of 19 potential COVID-19 mitigation factors (e.g. handwashing and mask wearing) was associated with lower odds of seropositivity (0.4 [0.1-0.99]) Finally, the presence of at least one household member in the age range of 6 to 17 years old was associated with higher odds of seropositivity (8.3 [1.2-57.0]).

CONCLUSIONS

The adjusted odds ratio of SARS-CoV-2 seroprevalence was significantly positively associated with increasing age and having household member(s) in the 6-17 year age group, while increasing income levels and a mitigation score at or above the median were shown to be significantly protective factors.

Immune response of heterologous versus homologous prime-boost regimens with adenoviral vectored and mRNA COVID-19 vaccines in immunocompromised patients

Due to rare but major adverse reactions to the AstraZeneca adenoviral ChAdOx1-S-nCoV-19 vaccine (ChAd), German health authorities recommended adults under 60 who received one dose of ChAd, to receive a second dose of the BioNTech mRNA BNT162b2 vaccine (BNT) as a booster. Studies in the general population suggest an enhanced efficacy of the heterologous (ChAd-BNT) compared to the homologous (BNT-BNT) vaccination regimen. However, an analysis of the efficacy in patient populations with a high risk of severe COVID-19 due to acquired immunodeficiency is still missing. We therefore compared both vaccination regimens in healthy controls, patients with gynecological tumors after chemotherapy, patients on dialysis and patients with rheumatic diseases concerning the humoral and cellular immune response. The humoral and cellular immune response differed substantially in healthy controls compared to patients with acquired immunodeficiency. Overall, the most significant differences between the two immunization regimens were found in neutralizing antibodies. These were always higher after a heterologous immunization. Healthy controls responded well to both vaccination regimens. However, the formation of neutralizing antibodies was more pronounced after a heterologous immunization. Dialysis patients, on the other hand, only developed an adequate humoral and particularly cellular immune response after a heterologous immunization. Tumor and rheumatic patients also - to a weaker extent compared to dialysis patients - benefited from a heterologous immunization. In conclusion, the heterologous COVID-19 vaccination regimens (ChAd-BNT) seem to have an advantage over the homologous vaccination regimens, especially in immunocompromised patients such as patients with end-stage kidney disease treated with hemodialysis.

Diagnostic performance of four lateral flow immunoassays for COVID-19 antibodies in Peruvian population

Serological assays have been used in seroprevalence studies to inform the dynamics of COVID-19. Lateral flow immunoassay (LFIA) tests are a very practical technology to use for this objective; however, one of their challenges may be variable diagnostic performance. Given the numerous available LFIA tests, evaluation of their accuracy is critical before real-world implementation. We performed a retrospective diagnostic evaluation study to independently determine the diagnostic accuracy of 4 different antibody-detection LFIA tests: Now Check (Bionote), CareStart (Access bio), Covid-19 BSS (Biosynex) and OnSite (CTK Biotech). The sample panel was comprised of specimens collected and stored in biobanks; specifically, specimens that were RT-PCR positive for SARS-CoV-2 collected at various times throughout the COVID-19 disease course and those that were collected before the pandemic, during 2018 or earlier, from individuals with upper respiratory symptoms but were negative for tuberculosis. Clinical performance (sensitivity and specificity) was analyzed overall, and subset across individual antibody isotypes, and days from symptoms onset. A very high specificity (98% - 100%) was found for all four tests. Overall sensitivity was variable, ranging from 29% [95% CI: 21%-39%] to 64% [95% CI: 54%-73%]. When considering detection of IgM only, the highest sensitivity was 42% [95% CI: 32%-52%], compared to 57% [95% CI: 47%-66%] for IgG only. When the analysis was restricted to at least 15 days since symptom onset, across any isotype, the sensitivity reached 90% for all four brands. All four LFIA tests proved effective for identifying COVID-19 antibodies when two conditions were met: 1) at least 15 days have elapsed since symptom onset and 2) a sample is considered positive when either IgM or IgG is present. With these considerations, the use of this assays could help in seroprevalence studies or further exploration of its potential uses.

Phenotypic Changes in T and NK Cells Induced by Sputnik V Vaccination

A highly effective humoral immune response induced by the Sputnik V vaccine was demonstrated in independent studies, as well as in large-scale post-vaccination follow-up studies. However, the shifts in the cell-mediated immunity induced by Sputnik V vaccination are still under investigation. This study was aimed at estimating the impact of Sputnik V on activating and inhibitory receptors, activation and proliferative senescence markers in NK and T lymphocytes. The effects of Sputnik V were evaluated by the comparison of PBMC samples prior to vaccination, and then three days and three weeks following the second (boost) dose. The prime-boost format of Sputnik V vaccination induced a contraction in the T cell fraction of senescent CD57⁺ cells and a decrease in HLA-DR-expressing T cells. The proportion of NKG2A⁺ T cells was down-regulated after vaccination, whereas the PD-1 level was not affected significantly. A temporal increase in activation levels of NK cells and NKT-like cells was recorded, dependent on whether the individuals had COVID-19 prior to vaccination. A short-term elevation of the activating NKG2D and CD16 was observed in NK cells. Overall, the findings of the study are in favor of the Sputnik V vaccine not provoking a dramatic phenotypic rearrangement in T and NK cells, although it induces their slight temporal non-specific activation.

A case of APMPPE-like panuveitis presenting with extensive outer retinal layer impairment following COVID-19 vaccination

BACKGROUND

Vaccination against the worldwide pandemic coronavirus disease 2019 (COVID-19) is underway; however, some cases of new onset uveitis after vaccination have been reported. We report a case of bilateral acute posterior multifocal placoid pigment epitheliopathy-like (AMPPE-like) panuveitis after COVID-19 vaccination in which the patient's pathological condition was evaluated using multimodal imaging.

CASE PRESENTATION

A 31-year-old woman experienced bilateral hyperemia and blurred vision starting 6 days after her second inoculation of the COVID-19 vaccination. At her first visit, her visual acuity was decreased bilaterally, and severe bilateral anterior chamber inflammation and bilateral scattering of cream-white placoid lesions on the fundus were detected. Optical coherence tomography (OCT) showed serous retinal detachment (SRD) and choroidal thickening in both eyes (OU). Fluorescein angiography (FA) revealed hypofluorescence in the early phase and hyperfluorescence in the late phase corresponding to the placoid legions. Indocyanine green angiography (ICGA) showed sharply marginated hypofluorescent dots of various sizes throughout the mid-venous and late phases OU. The patient was diagnosed with APMPPE and was observed without any medications. Three days later, her SRD disappeared spontaneously. However, her anterior chamber inflammation continued, and oral prednisolone (PSL) was given to her. Seven days after the patient's first visit, the hyperfluorescent lesions on FA and hypofluorescent dots on ICGA partially improved; however, the patient's best corrected visual acuity (BCVA) recovered only to 0.7 OD and 0.6 OS, and the impairment of the outer retinal layer was broadly detected as hyperautofluorescent lesions on fundus autofluorescence (FAF) examination and as irregularity in or disappearance of the ellipsoid and interdigitation zones on OCT, which were quite atypical for the findings of APMPPE. Steroid pulse therapy was performed. Five days later, the hyperfluorescence on FAF had disappeared, and the outer retinal layer improved on OCT. Moreover, the patient's BCVA recovered to 1.0 OU. Twelve months after the end of treatment, the patient did not show any recurrences.

CONCLUSIONS

We observed a case of APMPPE-like panuveitis after COVID-19 vaccination featuring some atypical findings for APMPPE. COVID-19 vaccination may induce not only known uveitis but also atypical uveitis, and appropriate treatment is required for each case.