Primary Vaccination Research Articles

THE RELATIONSHIP OF FAMILY SUPPORT WITH COMPLIANCE WITH THE BOOSTER VACCINATION IN THE ELDERLY AT RW 009 KAYU TINGGI, CAKUNG TIMUR, JAKARTA TIMUR

Booster vaccination is an effort to restore immunity and clinical protection that has decreased in the population found based on the survey results. Booster vaccinations are needed to maintain immunity and prolong the period of protection from primary vaccination. Family support is the key in accelerating the implementation of vaccination. Families who are aware of the importance of vaccines will influence their family members to follow the vaccine. The purpose of this study was to determine the relationship between family support and booster vaccination compliance in the elderly at RW 009 Kayu Tinggi, East Cakung, East Jakarta. Methods This research uses quantitative methods with cross sectional research. The population in this study were the elderly in RW 009 Kayu Tinggi, East Cakung, East Jakarta and the sample amounted to 110 respondents. Data collection technique using purposive sampling technique Research Results Statistical test using the chi square test with the results of respondents who have good family support as many as 57 (51.8%) and respondents with high adherence to booster vaccination as many as 56 (50.9%) obtained p value (0.000) < value (0.05) Based on the results of the study, there is a relationship between family support and adherence to booster vaccination in the elderly in RW 009 Kayu Tinggi, East Cakung, East Jakarta.

Comparison of measles plaque reduction neutralization test (PRNT) and measles virus-specific IgG ELISA for assessment of immunogenicity of measles-mumps-rubella vaccination at 5–7 months of age and maternal measles antibodies

BackgroundAssessing the risk of measles outbreaks and identifying the susceptible parts of the population is essential to timely intervention. Infants between 6–12 months are increasingly susceptible to measles but evaluating the performance of high throughput enzyme immunoassays (ELISAs) in infants < 9 months of age is lacking. MethodsA commercially available ELISA kit (Creative Diagnostics, DEIA359) for estimating measles seroprotection was evaluated in infants 5–7 months of age. In an immunogenicity substudy in the Danish MMR trial conducted between 2019–2021, infants (and mothers at baseline) were sampled before and one month after measles-mumps-rubella vaccination (MMR) or placebo as well as one month after routine MMR at 15 months. Measles IgG ELISA was compared to the gold standard but labor-intensive measles plaque reduction neutralization test (PRNT) by Pearson and Spearman correlations and by estimating sensitivity, specificity, and positive and negative predictive values (PPV and NPV). FindingsMeasles IgG levels compared to PRNT antibodies had a Pearson’s correlation coefficient between 0.10–0.24. Seroprotection rates measured by ELISA in young infants were 10–14% lower than measured by PRNT. The sensitivity of the ELISA to detect serological protection compared to PRNT in the infant population differed markedly across sampling time points and was 14%, 40%, and 92% at baseline, post-intervention, and post-routine MMR, whereas the specificity was 99%, 93%, and 43%, respectively. The PPV and NPV were 68% and 87% in infants at baseline. InterpretationThe correlation between measles IgG and PRNT antibodies was low. Seroprotection was underestimated using ELISA. High-accuracy tests are needed to avoid misclassifications and practices that lead to primary or secondary vaccine failure or retention of vaccination in outbreak settings. Baseline PPV and NPV suggested some applicability of ELISA in predicting serological protection in this age group. However, PRNT may be the only accurate estimator of serological protection in young infants.

State COVID-19 Vaccine Mandates and Uptake Among Health Care Workers in the US

Seventeen states introduced COVID-19 vaccine mandates for health care workers (HCWs) in mid-2021. Prior research on the effect of these mandates was centered on the nursing home sector, and more evidence is needed for their effect on the entire HCW population. To examine the association between state COVID-19 vaccine mandates for HCWs and vaccine uptake in this population. This repeated cross-sectional study included biweekly, individual-level data for adults aged 25 to 64 years who were working or volunteering in health care settings obtained from the Household Pulse Survey between May 26 and October 11, 2021. Analyses were conducted between November 2022 and October 2023. Announcement of a state COVID-19 vaccine mandate for HCWs. An indicator for whether a sampled HCW ever received a COVID-19 vaccine and an indicator for whether an HCW completed or intended to complete the primary COVID-19 vaccination series. Event study analyses using staggered difference-in-differences methods compared vaccine uptake among HCWs in mandate and nonmandate states before and after each mandate announcement. The sample was further stratified by the availability of regular COVID-19 testing in place of a vaccination (ie, a test-out option) and by the ages of HCWs (25-49 or 50-64 years) to examine heterogeneous associations. The study sample included 31 142 HCWs (mean [SD] age, 45.5 [10.6] years; 72.1% female) from 45 states, 16 of which introduced COVID-19 vaccine mandates for HCWs. Results indicated a mandate-associated 3.46-percentage point (pp) (95% CI, 0.29-6.63 pp; P = .03) increase in the proportion of HCWs ever vaccinated against COVID-19 and a 3.64-pp (95% CI, 0.72-6.57 pp; P = .02) increase in the proportion that completed or intended to complete the primary vaccination series 2 weeks after mandate announcement from baseline proportions of 87.98% and 86.12%, respectively. In the stratified analyses, positive associations were only detected in mandate states with no test-out option and among HCWs aged 25 to 49 years, which suggested vaccination increases of 3.32% to 7.09% compared with baseline proportions. This repeated cross-sectional study found that state COVID-19 vaccine mandates for HCWs were associated with increased vaccine uptake among HCWs, especially among younger HCWs and those in states with no test-out option. These findings suggest the potential for vaccine mandates to further promote vaccinations in an already highly vaccinated HCW population, especially when no test-out option is in place.

Immunogenicity and Protective Efficacy of an Acellular Pertussis Vaccine Candidate in a Mice Model.

Acellular pertussis vaccines (aPVs) have been developed as an alternative to whole-cell pertussis vaccines (wPVs) due to their similar efficacy but reduced reactogenicity. The aPV contains three or more immunogenic components of BP. We aimed to evaluate the immunogenicity and protective potency of an aPV vaccine produced in our laboratory consisting of pertussis toxin (PT), filamentous hemagglutinin (FHA), and pertactin (PRN) in mice. The aPV components were produced and purified from the supernatant and pellet of the bacterial culture. Two doses of formulated vaccine in parallel with two commercial vaccines, were administered intraperitoneally (IP) in mice at 3-week intervals. Antibody titers against aPV antigens were measured by ELISA after primary and booster vaccinations. To assess the protective efficacy, an intranasal challenge with a live pathogenic BP strain was conducted two weeks after the booster vaccination, and bacterial count (colony-forming unit, CFU) in the lungs was conducted two hours and ten days after the challenge. The results demonstrated a significant increase in antibody titers against all pertussis antigens in the serum of vaccinated groups compared to the negative control group, following both the primary and booster doses. No significant differences were observed between our formulation and the commercial vaccines. Furthermore, the CFU results showed complete eradication of infection 10 days after the challenge in all immunized groups, in contrast to the control group. Our aPV formulation, the first aPV candidate developed in Iran, exhibits immunogenicity and protective efficacy comparable to commercial vaccines. Further investigation in human subjects is warranted.

Formation of adaptive immunity against salmonellosis in cows using effector memory cells

The study aimed to investigate how the number of effector memory cells changes under the influence of a Salmonella vaccine antigen in cows. A homogeneous group of 100 Holstein-Friesian cows, kept under the same conditions, had blood samples taken. The blood was collected at four time points: before the first vaccination, and 7, 45, and 56 days after. The cows also received a booster vaccination on days 8-10. They were immunised with a polyvalent vaccine against livestock salmonellosis in Kazakhstan. Blood was separated into plasma and cellular fractions by centrifugation at 1,500 rpm for 10 minutes. The cellular fraction was then analysed by flow cytometry to determine the number of CD4+, CD8+, and γδ T-cell subpopulations at the four time points: before vaccination, and at 7-, 45-, and 56-days post-vaccination. Analysis of over 10,000 cells from each sample was conducted using FlowJo software. The data showed that the population of CD4+ and CD8+ T-lymphocytes and γδ T-cells increased 1.5 times by day 7 after the initial vaccination. The cows then received a booster dose on days 8-10, and by day 45 after the first vaccination, the CD4+ and CD8+ T-lymphocyte and γδ T-cell populations had increased threefold. CD45RA+ T-lymphocytes and γδ T-cells demonstrated a steady increase by day 45, followed by a decline in the numbers of T-cells across all phylogenetic groups. Thus, it can be concluded that the primary vaccination stimulates the development of long-term immune memory, while the booster dose triples the number of CD4+, CD8+, and γδ T-cell subpopulations. The findings provide insights into the mechanism of adaptive immunity formation in cows against salmonellosis through the use of effector memory cells and may be applied in developing vaccination strategies for cattle

Acceptability of HPV vaccination for cervical cancer prevention amongst emerging adult women in rural Mysore, India: a mixed-methods study

BackgroundIndia has the highest number of estimated deaths from cervical cancer globally, with most cases attributed to Human papillomavirus (HPV). The World Health Organization recommends primary HPV vaccination for girls ages 9–14, with catch-up vaccination for young women ≥ 15 if feasible. India authorized a new, inexpensive HPV vaccine in 2022; given anticipated vaccine expansion, we conducted a mixed-methods study exploring acceptability of HPV catch-up vaccination for young emerging adult women in rural Mysore, India.MethodsBetween September 2022-April 2023, participants were recruited with assistance from community health workers. In the qualitative phase, gender-stratified, audio-recorded focus group discussions (FGDs) were conducted in Kannada with emerging adults ages 18–26. FGDs were transcribed, translated, and analyzed using rapid approach to identify key HPV vaccination attributes. In the quantitative phase, a conjoint analysis was conducted to assess the impact of seven vaccination attributes on likelihood to vaccinate (LTV). Women ages 18–26 ranked LTV in eight hypothetical vaccination scenarios, and the relative impact of each attribute on LTV was calculated. All participants received education about cervical cancer, HPV, and HPV vaccination.ResultsFifty-two young adults (female = 31, male = 21) participated in seven FGDs, and 101 women participated in the conjoint analysis. Average age of the 153 participants was 22.5 years, 66.7% had married, and all had completed high school. Only 17.9% had heard of cervical cancer, and 2.7% knew of the HPV vaccine. FGDs identified seven HPV vaccination attributes: cost, vaccination location, family support, peer influence, dose number, side effects, and risk of acquiring HPV. In the conjoint analysis, all attributes except dose number significantly impacted LTV. Family support (impact score = 19.37, p < 0.0001) and peer influence (impact score = 18.01, p < 0.0001) had the greatest influence, followed by cost (impact score = 16.64, p < 0.0001) and HPV risk (impact score = 12.31, p < 0.0001). Vaccination location (government centers preferred) and side effects were also significant.ConclusionParticipants had poor knowledge of cervical cancer and HPV. Social attributes (family support, peer influence) had greatest impacts on LTV, and future studies should explore family-based interventions and peer education. Providing free vaccines at government centers through India’s national immunization program would maximize catch-up HPV vaccination for rural young women.

Multiple vaccine comparison in the same adults reveals vaccine-specific and age-related humoral response patterns: an open phase IV trial

Vaccine responsiveness is often reduced in older adults. Yet, our lack of understanding of low vaccine responsiveness hampers the development of effective vaccination strategies to reduce the impact of infectious diseases in the ageing population. Young-adult (25–49 y), middle-aged (50-64 y) and older-adult ( ≥ 65 y) participants of the VITAL clinical trials (n = 315, age-range: 28-98 y), were vaccinated with an annual (2019–2020) quadrivalent influenza (QIV) booster vaccine, followed by a primary 13-valent pneumococcal-conjugate (PCV13) vaccine (summer/autumn 2020) and a primary series of two SARS-CoV-2 mRNA-1273 vaccines (spring 2021). This unique setup allowed investigation of humoral responsiveness towards multiple vaccines within the same individuals over the adult age-range. Booster QIV vaccination induced comparable H3N2 hemagglutination inhibition (HI) titers in all age groups, whereas primary PCV13 and mRNA-1273 vaccination induced lower antibody concentrations in older as compared to younger adults (primary endpoint). The persistence of humoral responses, towards the 6 months timepoint, was shorter in older adults for all vaccines (secondary endpoint). Interestingly, highly variable vaccine responder profiles overarching multiple vaccines were observed. Yet, approximately 10% of participants, mainly comprising of older male adults, were classified as low responders to multiple vaccines. This study aids the identification of risk groups for low vaccine responsiveness and hence supports targeted vaccination strategies. Trial number: NL69701.041.19, EudraCT: 2019-000836-24.

Immunogenicity of Abdala COVID-19 vaccine in Vietnamese people after primary and booster vaccinations: A prospective observational study in Vietnam

ObjectivesWe studied the immunogenicity after primary and booster vaccinations of the Abdala COVID-19 vaccine, a receptor-binding domain protein subunit vaccine, in Vietnamese people by determining the level of neutralization and cross-neutralization activities against the ancestral SARS-CoV-2 and its variants and SARS-CoV-1. MethodsWe performed a prospective observational study, enrolling adults aged 19-59 years in Dong Thap province, southern Vietnam, and collected blood samples from baseline until 4 weeks after the booster dose. We measured anti-nucleocapsid, anti-spike, and neutralizing antibodies against SARS-CoV-2 and assessed the cross-neutralization against 14 SARS-CoV-2 variants and SARS-CoV-1. Complementary antibody data came from Vietnamese health care workers fully vaccinated with ChAdOx1-S. ResultsAfter primary vaccination, anti-spike antibody and neutralizing antibodies were detectable in 98.4% and 87% of 251 study participants, respectively, with neutralizing antibody titers similar to that induced by ChAdOx1-S vaccine. Antibody responses after a homologous (Abdala COVID-19) or heterologous (messenger RNA BNT162b2) booster could neutralize 14 SARS-CoV-2 variants (including Omicron) and SARS-CoV-1. ConclusionsAbdala COVID-19 vaccine is immunogenic in Vietnamese people. Enhanced antibody response after a booster dose could cross-neutralize 14 SARS-CoV-2 variants and SARS-CoV-1. Our results have added to the growing body of knowledge about the contribution of protein subunit vaccine platforms to pandemic control.

Factors affecting the outcome of primary rabies vaccination in young cats

Limited data exist on the factors affecting feline rabies vaccination outcomes during primary immunization. This study aimed to assess if specific factors (signalment, vaccination count, vaccine brand, and time since last vaccination) correlated with meeting global antibody titer standards and absolute titers in young cats given monovalent inactivated rabies vaccines. Analyzing a dataset from cats tested before their first annual booster using the FAVN test, logistic and linear regression models were applied. Among 379 cats, 94.2 % achieved titers meeting or exceeding the standard threshold (≥0.5 IU/ml). Time since last vaccination proved to be the primary predictor of vaccination success. Cats receiving two vaccinations tended toward higher titers. Age, sex, breed, and vaccine type showed no impact on outcomes. The present study indicates that vaccination failure in young cats is uncommon, and that the time interval from the latest vaccination is the single most important predictor of successful rabies vaccination.

Boost and Increased Antibody Breadth Following a Second Dose of PARVAX for SARS-CoV-2 in Mice and Nonhuman Primates.

PARVAX is a genetic vaccine platform based on an adeno-associated vector that has demonstrated to elicit potent, durable, and protective immunity in nonhuman primates (NHPs) after a single dose. Here, we assessed vaccine immunogenicity following a PARVAX prime-boost regimen against SARS-CoV-2. In mice, a low-dose prime followed by a higher-dose boost elicited potent neutralizing antibody responses and distinct cross-reactivity profiles, depending on the antigen used in the booster vaccine. However, the potent neutralizing anti-vector antibody responses developed in mice limited the dose that could be administered as a prime. We further explored the re-administration efficacy in NHPs primed with a SARS-CoV-2 Delta vaccine and boosted with an Omicron BA.1 vaccine at week 15, after the primary response peak antibody levels were reached. The boost elicited an increase in antibodies against several Omicron variants, but no increase was detected in the antibody titers for other variants. The anti-vector responses were low and showed some increased subsequent boosts but generally declined over time. The potent prime vaccination limited the detection of the boosting effect, and therefore, the effect of anti-vector immunity was not fully elucidated. These data show that PARVAX can be effectively re-administered and induce a novel antigenic response.

Anti-SARS-CoV-2 antibody dynamics after primary vaccination with two-dose inactivated whole-virus vaccine, heterologous mRNA-1273 vaccine booster, and Omicron breakthrough infection in Indonesian health care workers

BackgroundData on the dynamics and persistence of humoral immunity against SARS-CoV-2 after primary vaccination with two-dose inactivated vaccine (CoronaVac) are limited. This study evaluated the sequential effects of prior infection, heterologous boosting with mRNA-1273 (Moderna), and the occurrence of Omicron vaccine-breakthrough infection (VBI) thereafter.MethodsWe evaluated anti-spike IgG (Abbott) and neutralising (cPASS/GenScript) antibody (nAb) titers up to one year after mRNA-1273 boost in two-dose-CoronaVac-primed Indonesian healthcare workers (August 2021-August 2022). We used linear mixed modeling to estimate the rate of change in antibody levels, and logistic regression to examine associations between antibody levels and VBI.ResultsOf 138 participants, 52 (37.7%) had a prior infection and 78 (56.5%) received an mRNA-1273 booster. After two-dose CoronaVac, antibody titers had significantly declined within 180 days, irrespective of prior infection. After mRNA-1273 booster, anti-spike IgG (1.47% decline/day) and Omicron B.1.1.529/BA.2 nAbs declined between day 28–90, and IgG titers plateaued between day 90–360. During the BA.1/BA.2 wave (February–March 2022), 34.6% (27/78) of individuals experienced a VBI (median 181 days after mRNA-1273), although none developed severe illness. VBI was associated with low pre-VBI anti-spike IgG and B.1.1.529/BA.2 nAbs, which were restored post-VBI.ConclusionsmRNA-1273 booster after two-dose CoronaVac did not prevent BA.1/BA.2 VBI. Periodic vaccine boosters may be warranted against emerging SARS-CoV-2 variants.

Antibody response after feline panleukopenia virus vaccination in kittens with and without intestinal parasites.

Vaccinations should only be given to healthy cats, and deworming before vaccination is generally recommended; however, so far, no study has investigated the influence of intestinal parasitic infection on the immune response in kittens. The aim of this prospective study was to compare the antibody response to feline panleukopenia virus (FPV) vaccination in kittens with and without intestinal parasites. Overall, 74 healthy kittens were included. Of these, 17 had intestinal parasites (12/17 Toxocara cati, 6/17 Cystoisospora felis, 1/17 Capillaria species). Both kittens with and without (n = 57) parasites received two primary kitten vaccinations with modified live FPV vaccines in a 4-week interval starting at the age of 8-12 weeks. Anti-FPV antibodies were determined at the beginning of the study (week 0) and at week 8 (4 weeks after the second vaccination) by haemagglutination inhibition. A ⩾four-fold titre increase (week 8 vs week 0) was defined as a response to vaccination. Comparison of the immune response in the kittens with and without intestinal parasites was performed using Pearson's χ2 test. Pre-vaccination antibodies were present in 4/17 (23.5%) kittens with intestinal parasites and in 24/57 (42.1%) without parasites. A ⩾four-fold titre increase was seen in 13/17 (76.5%) kittens with parasites compared with 32/57 (56.1%) kittens without parasites. There was neither a significant difference in pre-vaccination antibodies (P = 0.17), nor in vaccination response (P = 0.13) between kittens with and without parasites. The results indicate that asymptomatic intestinal infections with endoparasites do not interfere with the immune response to kitten vaccination series. Parasitic infection (at least with T cati, C felis and Capillaria species) is therefore not a reason to postpone important vaccinations.

Safety and 6-month immune persistence of inactivated poliovirus vaccine (Sabin strains) simultaneously administrated with other vaccines for primary and booster immunization in Jiangxi Province, China

ObjectivesThis study aims to evaluate the safety of a new inactivated poliomyelitis vaccine (Sabin strains) (sIPV) for large-scale use in primary and booster immunizations, whether simultaneously administered with other vaccines or not and to explore the persistence of all vaccines at approximately six months after vaccination. MethodA total of 3200 infants were recruited into this study, including 2000 infants aged 2–3 months randomly assigned (1:1) into the “sIPV basic” or the “sIPV+DTaP” group for primary immunization of sIPV. Another 1200 children aged 18 months old and above were randomly assigned (2:2:1:1) into the “sIPV booster,” “sIPV+HepA-I,” “sIPV+MMR”, or “sIPV+HepA-L" group for booster immunization of sIPV. Adverse events within 30 days of each vaccination dose in all participants were self-reported by guardians using a WeChat mini-program. Approximately 200 blood samples were collected at 5–7 months after the final vaccination to test for antibodies against poliovirus and other viruses. Results3198 participants in total were included in the safety study, including 1999 infants aged 2–3 months old and 1199 children aged 18–26 months old.For primary immunization, the incidence of adverse reactions in the “sIPV basic” and the “sIPV+DTaP” group were 3.19 and 6.21% (P = 0.001), respectively. For booster immunization, the incidences of adverse reaction for the “sIPV booster” group were 2.25%, while the incidence for the “sIPV +others” group in total was 2.50% (P = 0.788). Most adverse reactions were mild. Fever was the most common symptom in all groups. No vaccine-related serious adverse events (SAEs) were observed in this study.The seropositivity rates of antibodies in the “sIPV basic” and the “sIPV+DTaP” group were 92.31 and 100% against type 1 poliovirus (P = 0.031); 96.15% and 98.57% against type 2 poliovirus (P = 0.575); 98.08% and 91.43% against type 3 poliovirus (P = 0.237), respectively. Regarding booster vaccination with sIPV, whether co-administered with other vaccines or not, the seropositivity rates of antibodies against the three types of polioviruses were all 100%. Seropositivity rates of antibodies against hepatitis A, measles, mumps, and rubella were all no <77%, except for pertussis, which was <30%. ConclusionsIPV demonstrated good safety and immune persistence for primary and booster vaccinations, whether administered singly or simultaneously. Antibodies against hepatitis A, measles, mumps and rubella were not disrupted by the co-vaccination. However, the seropositivity rates and geometric mean concentrations (GMCs) of antibodies against pertussis indicate the necessity for a booster dose.

Analyzing Google COVID-19 Vaccine Intent Search Trends and Vaccine Readiness in the United States: Panel Data Study.

Factors such as anxiety, worry, and perceptions of insufficient knowledge about a topic motivate individuals to seek web-based health information to guide their health-related decision-making. These factors converged during the COVID-19 pandemic and were linked to COVID-19 vaccination decision-making. While research shows that web-based search relevant to COVID-19 was associated with subsequent vaccine uptake, less is known about COVID-19 vaccine intent search (which assesses vaccine availability, accessibility, and eligibility) as a signal of vaccine readiness. To increase knowledge about vaccine intent search as a signal of vaccine readiness, we investigated the relationship between COVID-19 vaccine readiness and COVID-19 vaccine intent relative search volume on Google. We compiled panel data from several data sources in all US counties between January 2021 and April 2023, a time during which those with primary COVID-19 vaccinations increased from <57,000 to >230 million adults. We estimated a random effects generalized least squares regression model with time-fixed effects to assess the relationship between county-level COVID-19 vaccine readiness and COVID-19 vaccine intent relative search volume. We controlled for health care capacity, per capita COVID-19 cases and vaccination doses administered, and sociodemographic indicators. The county-level proportions of unvaccinated adults who reported that they would wait and see before getting a COVID-19 vaccine were positively associated with COVID-19 vaccine intent relative search volume (β=9.123; Z=3.59; P<.001). The county-level proportions of vaccine-enthusiast adults, adults who indicated they were either already vaccinated with a primary COVID-19 vaccine series or planned to complete the vaccine series soon, were negatively associated with COVID-19 vaccine intent relative search volume (β=-10.232; Z=-7.94; P<.001). However, vaccine intent search was higher in counties with high proportions of people who decided to wait and see and lower in counties with high proportions of vaccine enthusiasts. During this period of steep increase in COVID-19 vaccination, web-based search may have signaled differences in county-level COVID-19 vaccine readiness. More vaccine intent searches occurred in high wait-and-see counties, whereas fewer vaccine intent searches occurred in high vaccine-enthusiast counties. Considering previous research that identified a relationship between vaccine intent search and subsequent vaccine uptake, these findings suggest that vaccine intent search aligned with people's transition from the wait-and-see stage to the vaccine-enthusiast stage. The findings also suggest that web-based search trends may signal localized changes in information seeking and decision-making antecedent to vaccine uptake. Changes in web-based search trends illuminate opportunities for governments and other organizations to strategically allocate resources to increase vaccine uptake. Resource use is part of the larger public policy decisions that influence vaccine uptake, such as efforts to educate the public during evolving public health crises, including future pandemics.

Evaluation of cross-neutralizing immunity following COVID-19 primary series vaccination during the Omicron surge in Tanzania.

COVID-19 vaccine became available in Tanzania during the first wave of the Omicron variant. During that time community seroprevalence of SARS-CoV-2 was already at 50%-80%. To date, it remains largely unknown whether ongoing vaccination with the primary series vaccines has any meaningful immune-boosting effects against newer Omicron subvariants. Therefore, we tested cross-neutralizing capacity of antibodies elicited by infection, vaccination, or both against SARS-CoV-2 Omicron subvariants BA.1, and the newer subvariants BQ.1.1 and XBB.1.5. that were unexperienced by this population. Participants who were either SARS-CoV-2 infected-only (n = 28), infected vaccinated (n = 22), or vaccinated-only (n = 73) were recruited from Dar-es-Salaam, Tanzania, between April and December 2022. Plasma 50% neutralization titers (NT50) against SARS-CoV-2 wild-type strain and Omicron subvariants were quantified by a lentiviral-based pseudo-virus assay. Percentage of participants with neutralizing activity against WT and BA.1 was high (>85%) but was reduced against BQ.1.1 (64%-77%) and XBB.1.5 (35%-68%) subvariants. The low median cross-neutralization titer was slightly higher in the infected vaccinated group compared to vaccine-only group against BQ.1.1 (NT50 148 vs. 85, p = 0.032) and XBB.1.5 (NT50 85 vs. 37 p = 0.022) subvariants. In contrast, vaccine-boost among the infected vaccinated did not result to increased cross-neutralization compared to infected-only participants (BQ.1.1 [NT50 of 148 vs. 100, p = 0.501] and XBB.1.5 [NT50 86 vs. 45, p = 0.474]). We report severely attenuated neutralization titers against BQ.1.1 and XBB.1.5 subvariants among vaccinated participants, which marginally improved in the infected vaccinated participants. Our findings call for further studies to evaluate effectiveness of the primary series vaccines in preventing severe infection and mortality against the newer variants.

Comparison of Post-Vaccination Response (Humoral and Cellular) to BNT162b2 in Clinical Cases, Kidney and Pancreas Transplant Recipient with Immunocompetent Subjects over Almost Two Years of Parallel Monitoring.

Vaccination is one of the most effective medical interventions to prevent infectious diseases. The introduction of vaccines against coronavirus acute respiratory syndrome 2 (SARS-CoV-2) was aimed at preventing severe illness and death due to coronavirus disease 2019 (COVID-19). Solid organ transplant recipients (SOTRs) are at high risk of infection with SARS-CoV-2 and serious effects associated with COVID-19, mainly due to the use of immunosuppressive therapies, which further cause suboptimal response to COVID-19 vaccination. We aimed to compare post-vaccination response to BNT162b2 in kidney-pancreas transplant recipient, specifically in immunocompetent individuals, over two years of simultaneous monitoring. To determine the humoral response, the levels of the IgG and IgA anti-S1 antibodies were measured. To assess the cellular response to SARS-CoV-2, the released IFN-γ-S1 was determinate. After primary vaccination, compared to immunocompetent subjects, SOTR showed lower seroconversion for both antibody classes. Only the additional dose produced antibodies at the level reached by the control group after the baseline vaccination. During the monitored period, SOTR did not achieve a positive cellular response in contrast to immunocompetent individuals, so in order to obtain longer protection, including immune memory, the adoption of booster doses of the vaccine should be considered.

Exploring influential factors in childhood vaccine delays in Riyadh, Saudi Arabia.

Infectious diseases present a substantial worldwide health challenge, yet vaccines have played a crucial role in significantly decreasing illness rates. Despite their effectiveness, global vaccination coverage stands at 85%, leaving a considerable number of infants without routine immunization. Our study seeks to examine the occurrence of delayed primary vaccination and the factors influencing it in Riyadh, Saudi Arabia addressing a critical void in current research. A cross-sectional investigation was carried out in the primary care facilities of the first health cluster in Riyadh, Saudi Arabia. Information was gathered utilizing a well-structured questionnaire, modified from a prior study. The study encompassed children aged two years and younger, accompanied by their parents who brought their vaccination cards for the visit. Non-probability convenience sampling was employed for data collection. Subsequently, the data underwent thorough cleaning in Excel (Microsoft Excel) and was subjected to analysis using IBM SPSS 29 (IBM SPSS Statistics 29). The study involved 402 participants, primarily over 12 months old, with a balanced gender distribution. Noteworthy findings indicate a 20.9% prevalence of childhood vaccine delays, with reasons such as high-grade fever (33.3%) and travel (26.2%). Significant associations were found in children aged 6-12 months (25.8%, P = 0.039), families with over four children (31%, P = 0.010), perceptions of vaccine harm (50.0%, P = 0.013), and acknowledgment of neglect (96.4%, P = 0.001). The research illuminates the complex factors influencing childhood vaccine delays in Saudi Arabia. Stressing the significance of personalized interventions, it underscores the necessity to tackle challenges specific to age, parental perspectives, and access issues for improved vaccination outcomes.

Statistical considerations for the platform trial in COVID-19 vaccine priming and boosting

The Platform trial In COVID-19 priming and BOOsting (PICOBOO) is a multi-site, adaptive platform trial designed to generate evidence of the immunogenicity, reactogenicity, and cross-protection of different booster vaccination strategies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its variants, specific for the Australian context. The PICOBOO trial randomises participants to receive one of three COVID-19 booster vaccine brands (Pfizer, Moderna, Novavax) available for use in Australia, where the vaccine brand subtypes vary over time according to the national vaccine roll out strategy, and employs a Bayesian hierarchical modelling approach to efficiently borrow information across consecutive booster doses, age groups and vaccine brand subtypes. Here, we briefly describe the PICOBOO trial structure and report the statistical considerations for the estimands, statistical models and decision making for trial adaptations. This paper should be read in conjunction with the PICOBOO Core Protocol and PICOBOO Sub-Study Protocol 1: Booster Vaccination. PICOBOO was registered on 10 February 2022 with the Australian and New Zealand Clinical Trials Registry ACTRN12622000238774.

Latinx youth's and parents' covid-19 beliefs, vaccine hesitancy and vaccination rates: Longitudinal associations in a community sample.

The Latinx population has the second highest COVID-19 death rate among racial/ethnic groups in the United States and less than half of Latinx youth aged 5-17 years old completed their COVID-19 primary vaccination series as of September 2022. COVID-19 vaccine misinformation detrimentally impacts vaccination rates. In this study, we examined factors that predicted Latinx youth COVID-19 vaccine hesitancy and vaccination status. A community-based sample of 290 Latinx parent and adolescent dyads from a Southwestern metropolitan area of the United States who were recruited to complete an online survey at baseline at T1 (August 2020 -March 2021) and one year later. We tested a longitudinal mediation model in which we examined individual and family factors that would predict youth COVID-19 vaccine hesitancy and vaccination status over time. Youth's pandemic disbelief (i.e., the belief that the COVID-19 pandemic is a conspiracy or not real) predicted greater youth's COVID-19 vaccine hesitancy, and in turn, a lower likelihood of youth's COVID-19 vaccination. Youth's pandemic disbelief also predicted greater parent's vaccination hesitancy which, in turn, predicted greater youth's vaccination hesitancy and a lower likelihood of COVID-19 vaccination. Parents' pandemic disbelief predicted their own COVID-19 hesitancy, but not youth hesitancy. Our study findings provide initial evidence that general pandemic disbelief was a significant driver of vaccine hesitancy and vaccination among Latinx families. The study contributes to the limited research investigating COVID-19 vaccination in the Latinx community and among Latinx youth, further aiding how COVID-19 vaccine disparities can be mitigated among racial/ethnic populations.

Evaluating the delivery of care by telemedicine for incarcerated people living with HIV: a cohort study

BackgroundThe use of telemedicine has grown significantly since the COVID-19 pandemic and has the potential to improve access to specialized care for otherwise underserved populations. Incarcerated people living with HIV (PLWH) could potentially benefit from expanded access to HIV care through telemedicine.MethodsAll PLWH who were incarcerated within the Tennessee Department of Corrections and received care through the HIV telemedicine clinic at Regional One Hospital between 5/1/2019 through 2/28/2022 were identified from the electronic health records (EHR). Demographics, laboratory data, vaccine history, and treatment outcomes were abstracted from the EHR. Retention in care and viral suppression were defined using Centers for Disease Control and Prevention definitions.ResultsOf the 283 incarcerated PLWH receiving care from this telemedicine clinic, 78% remained retained in care and 94% achieved or maintaining viral suppression at 12 months. Many preventative care measures remained unperformed or undocumented, including vaccinations and testing for concurrent sexually transmitted infections. There were 56 patients (20%) found to have chronic hepatitis C in this population, with 71% either cured or still on treatment in this study period.ConclusionsRetention in care and viral suppression rates were excellent among incarcerated PLWH receiving telemedicine care for their HIV. HIV related primary health care screenings and vaccinations, however, were less consistently documented and represent areas for improvement.