People living with HIV are at higher risk of severe illness due to common respiratory pathogens. We estimated uptake of influenza, pneumococcal, and COVID-19 vaccines among people engaged in HIV care in Ontario, Canada, and identified factors associated with vaccine uptake. We conducted a cross-sectional analysis of interviewer-administered, annual questionnaires (2021–2023) linked to medical charts and laboratory data. We used modified Poisson regression to calculate adjusted prevalence ratios and 95

BACKGROUND:We compared the prevalence of vaccine-preventable anal human papillomavirus (HPV) types among gay, bisexual, and other men who have sex with men (GBM) living in large cities in Canada from 2019 to 2021 by age and HIV status. METHODS:Sexually-active GBM ≥16 years were recruited in Montreal, Toronto, and Vancouver using respondent-driven sampling (RDS). Participants self-reported HPV vaccination and self-collected anal HPV specimens. We estimated the prevalence of vaccine-preventable types for participants during the 2019 to 2021 period. We report RDS-II-weighted prevalence and confounder-adjusted prevalence ratios (aPRs) comparing vaccinated (≥1 dose) and unvaccinated GBM using multivariable Poisson regression. RESULTS:Among 1,159 participants aged 18-83 (median 35 years), 17.6% were living with HIV, and 62.2%, 40.2% and 15.0% were vaccinated in the 16-26, 27-45, and ≥46-year groups, respectively. Among GBM 16-26 years, HPV6/11/16/18 prevalence was lower among those vaccinated ≤23 years (aPR= 0.40, 95% CI: 0.20-0.77), ≥3 years since first dose (aPR=0.39; 95% CI: 0.18-0.85), and those with ≤5 years of sexual activity before vaccination (aPR=0.47; 95%CI: 0.25-0.89). HPV6/11/16/18/31/33/45/52/58 prevalence was lower among those vaccinated ≤26 years in GBM aged 27-45 years (aPR= 0.81, 95% CI, 0.61-1.08), though this did not reach statistical significance. CONCLUSIONS:Five years after implementation of Canadian HPV vaccination programs for younger GBM, anal HPV prevalence was lower among those vaccinated at younger ages and near sexual debut.

INTRODUCTION:COVID-19 vaccination significantly reduces COVID-19-related hospitalization and mortality and is important for those who may be at increased risk of SARS-CoV-2 infection, including people living with HIV. Using a population-based approach, we examined COVID-19 vaccine uptake among people living with and without HIV in Ontario, Canada. METHODS:A retrospective population-based matched cohort study was conducted using provincial clinical and health administrative data from December 14, 2020 to August 31, 2022. Community-dwelling adults living with HIV aged ≥19 years were matched one-to-one with a person without a diagnosis of HIV based on age, sex, geography, and immigration status. To identify predictors of vaccine uptake, modified Poisson regression with robust standard errors accounting for geographical clustering was used. To estimate vaccine uptake comparing the HIV and non-HIV cohorts, conditional Poisson regression with robust error variance was used to estimate crude and adjusted risk ratios with 95 % confidence intervals (CI). RESULTS:Among 20,903 people living with HIV, most (85.4%) had received ≥2 COVID-19 vaccine doses, with 64.7% receiving a third dose and 24.3% receiving a fourth dose. Disparities in uptake of ≥3 doses by sex were observed (males vs females: 68.5% vs 50.9%). Predictors of receiving ≥3 doses among people living with HIV included older age, male sex, and receipt of a recent influenza vaccine. Men living with HIV were more likely to receive ≥3 doses compared with men living without HIV, whereas women living with HIV were less likely than women living without HIV to receive ≥3 doses. CONCLUSIONS:Uptake of the first two doses of COVID-19 vaccine was high among people living with HIV in Ontario, Canada, however, disparities in uptake of ≥3 doses remain, especially by sex. Continued monitoring of COVID-19 vaccine uptake is crucial to informing immunization programs, policies and guidelines for people living with HIV in Canada.

We found that risk of SARS-CoV-2 breakthrough infection did not meaningfully differ between a population-based cohort of vaccinated people with HIV and a matched cohort of people without HIV after accounting for sociodemographic factors, previous SARS-CoV-2 infection, SARS-CoV-2 testing patterns and COVID-19 vaccine doses (14 December 2020 to 5 May 2024). However, rates of breakthrough infection were higher among men with HIV compared to without HIV during the pre-Omicron era.

BackgroundForeign-born children may face greater barriers to accessing routine immunizations in Canada or their country of birth, but provincial surveillance data on immigration status are lacking. Using our provincial immunization repository linked to administrative data, we assessed immunization coverage among immigrant and refugee children in Ontario, Canada, compared with Ontario-born children and identified factors associated with being up-to-date (UTD).MethodsWe conducted a retrospective cohort study of children entering school during the 2012/13-2014/15 school years. We calculated UTD coverage for measles (2 doses), diphtheria (4 doses), and polio (3 doses) vaccines at school entry and two years after school attendance. We compared UTD coverage between immigrant/refugee children and Ontario-born children using standardized differences (SD).ResultsIn a cohort of 363,662 children, 15,114 (4.2%) were immigrants/refugees (82.1% immigrants, 17.9% refugees). UTD coverage for all antigens combined was 59.2% among immigrant/refugee children compared with 87.9% among Ontario-born children at school entry (SD = 0.69), increasing to 84.9% and 94.3%, respectively, two years after school entry (SD = 0.31). Coverage was lower with greater disparities between immigrant/refugee and Ontario-born children for measles (87.9% vs. 94.8%, SD = 0.25) and diphtheria (94.6% vs. 97.4%, SD = 0.15) after two years than polio (97.1% vs. 98.4%, SD = 0.09). Among immigrant/refugee children, coverage was lowest in refugees (vs. immigrants), recent immigrants, and those born in certain regions.ConclusionsImmunization coverage among foreign-born children lagged behind their Ontario-born peers, even after two years of school attendance. Findings varied by vaccine, immigration category, time spent in Ontario, and country of birth.

We found that rates of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) testing and reverse transcriptase (RT)-PCR-confirmed infection were approximately 50% higher in a population-based cohort of people with HIV compared with a matched cohort of people without HIV during the Omicron era (2 January 2022 to 31 March 2023) in Ontario, Canada, after controlling for age, sex, residential census tract, and country of birth. Rates of coronavirus disease 2019 (COVID-19)-related hospitalization and/or death were more than double. Differences persisted independent of vaccination, healthcare access, and COVID-19 diagnosis.

COVID-19 breakthrough infection (BTI) can occur despite vaccination. Using a multi-centre, prospective, observational Canadian cohort of people with HIV (PWH) receiving ≥2 COVID-19 vaccines, we compared the SARS-CoV-2 spike (S) and receptor-binding domain (RBD)-specific IgG levels 3 and 6 months post second dose, as well as 1 month post third dose, in PWH with and without BTI. BTI was defined as positivity based on self-report measures (data up to last study visit) or IgG data (up to 1 month post dose 3). The self-report measures were based on their symptoms and either a positive PCR or rapid antigen test. The analysis was restricted to persons without previous COVID-19 infection. Persons without BTI remained COVID-19-naïve until ≥3 months following the third dose. Of 289 participants, 92 developed BTI (31.5 infections per 100 person-years). The median days between last vaccination and BTI was 128 (IQR 67, 176), with the most cases occurring between the third and fourth dose (n = 59), corresponding to the Omicron wave. In analyses adjusted for age, sex, race, multimorbidity, hypertension, chronic kidney disease, diabetes and obesity, a lower IgG S/RBD (log10 BAU/mL) at 1 month post dose 3 was significantly associated with BTI, suggesting that a lower IgG level at this time point may predict BTI in this cohort of PWH.

Background Oral human papillomavirus (HPV) infections are a leading cause of oropharyngeal cancers. In 2015 and 2016, HPV vaccines became publicly funded for gay, bisexual, and other men who have sex with men (GBM) under 27 years of age in most Canadian provinces.Methods Between 2017 and 2019, sexually active GBM in Montreal, Toronto, and Vancouver were recruited through respondent-driven sampling. Participants aged 16-30 years were invited to self-collect oral rinse specimens for HPV testing. We estimated HPV prevalence in the oral tract overall and compared these by vaccination status.Results Among the 838 GBM with a valid oral specimen, 36.9% reported receiving >= 1 dose of HPV vaccine. Overall, oral HPV prevalence was 2.6% (95% confidence interval [CI], 1.5%-3.7%) for at least 1 HPV type and 1.2% (95% CI, .5%-1.9%) for any high-risk type. We detected quadrivalent (HPV 6/11/16/18) vaccine-preventable types in 0.3% (95% CI, .0%-1.0%) of vaccinated individuals and 1.1% (95% CI, .1%-2.0%) of unvaccinated individuals.Conclusions Oral HPV prevalence was low in a population of young urban GBM in Canada, of whom 37% were vaccinated. Findings serve as a benchmark for monitoring of vaccination impacts on oral HPV infection within this priority population. In a cohort of young Canadian gay, bisexual, and other men who have sex with men (approximately 37% vaccinated), prevalence of oral human papillomavirus infection was relatively low overall with estimates higher for those unvaccinated compared to those vaccinated.

Background: Understanding the roots of vaccine confidence in vulnerable populations, such as persons living with HIV (PLWH), is important to facilitate vaccine uptake, thus mitigating infection and spread of vaccinepreventable infectious diseases. In an online survey of PLWH conducted in Canada during winter 2022 (AIDS and Behav 2023), we reported that the overall COVID-19 vaccination uptake rate in PLWH was similar by sex. Here, we examined attitudes and beliefs towards vaccination against COVID-19 based on sex. Methods: Between February and May 2022, PLWH across Canada were recruited via social media and community-based organizations to complete an online survey consisting of a modified Vaccine Hesitancy Scale (VHS) questionnaire with items from the National Advisory Committee on Immunization Acceptability Matrix. Descriptive statistics were used to summarize participant characteristics and responses to the VHS questionnaire by sex. The effect of biological sex on total VHS score, two subscales ("lack of confidence" and "perceived risk") was assessed separately by linear regression adjusting for other key baseline variables. Results: Of 259 PLWH, 69 (27 %) were females and 189 (73 %) were males. Sixty-six (26 %) of participants self- identified as a woman, 163(63 %) as a man and 28(11 %) as trans/two-spirited/queer/non-binary/agender/ other. The mean age (SD) was 47 +/- 14 years. Females were less likely to believe that COVID-19 vaccination was: important for his/her own health (71 % vs. 86 %); a good way to protect themselves from infection (68 % vs. 86%); that getting the COVID-19 vaccine was important for the health of others in his/her community (78 % vs. 91 %); believed recommendations by their doctor/health care provider about COVID-19 vaccines (78 % vs. 88 %); that information about COVID-19 vaccines from public health officials was reliable and trustworthy (56% vs. 75 % vs); COVID-19 vaccines are effective in preventing COVID-19 infections (61 % vs. 82 %) and that all COVID-19 vaccines offered by government programs in their communities were important for good health (70 % vs. 87 %). Although more males than females felt that new vaccines generally carry more risks than older vaccines (19 % vs 16 %,), fewer males than females endorsed concern about serious side effects of COVID-19 vaccines (33 % vs 45 %). The linear regression model showed females had a significantly higher VHS total score than males (adjusted mean difference 0.38; 95% confidence interval (CI) 0.13-0.64; p = 0.004), indicating greater COVID-19 vaccine hesitancy among females. It was observed that females had a greater "lack of confidence in vaccines" score than males (adjusted mean difference 0.43; 95 % CI 0.14-0.73; p = 0.004). We did not observe a significant difference in "perceived risk in vaccines" between males and females (adjusted mean difference 0.20; 95 % CI- 0.07-0.46; p = 0.1). The inadequate number of participants self-identifying as different from biological sex at birth pre- vented us from analyzing the VHS score based on gender identity. Conclusions: Among PLWH, females showed greater COVID-19 vaccine hesitancy than males. Specifically, compared with males, females had a higher level of lack of confidence in vaccines. Fewer females than males believed that COVID-19 vaccines had health benefits at both the personal and societal levels and that recom- mendations made by their doctor/health care provider and public health officials are reliable and trustworthy. Further investigation into reasons for this difference in opinion still needs to be elucidated. Educational in- terventions targeted toward females living with HIV are especially needed to increase confidence in vaccination.

Objectives: We estimated the effectiveness of COVID-19 vaccines against laboratory-confirmed SARS-CoV-2 infection among people living with HIV (PLWH) and compared the estimates with a matched HIV -negative cohort.Methods: We used the British Columbia COVID-19 Cohort, a population-based data platform, which inte-grates COVID-19 data on SARS-CoV-2 tests, laboratory-confirmed cases, and immunizations with provin-cial health services data. The vaccine effectiveness (VE) was estimated with a test-negative design using the multivariable logistic regression.Results: The adjusted VE against SARS-CoV-2 infection was 71.1% (39.7, 86.1%) 7-59 days after two doses, rising to 89.3% (72.2, 95.9%) between 60 and 89 days. VE was preserved 4-6 months after the receipt of two doses, after which noticeable waning was observed (51.3% [4.8, 75.0%]). In the matched HIV-negative cohort (n = 375,043), VE peaked at 91.4% (90.9, 91.8%) 7-59 days after two doses and was sustained for up to 4 months, after which evidence of waning was observed, dropping to 84.2% (83.4, 85.0%) between 4 and 6 months.Conclusion: The receipt of two COVID-19 vaccine doses was effective against SARS-CoV-2 infection among PLWH pre-Omicron. VE estimates appeared to peak later in PLWH than in the matched HIV-negative co-hort and the degree of waning was relatively quicker in PLWH; however, peak estimates were comparable in both populations. (c) 2022 The Authors. Published by Elsevier Ltd on behalf of International Society for Infectious Diseases. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ )

Objective: To examine the risk of hospitalization within 14 days of COVID-19 diagnosis among people living with HIV (PLWH) and HIV-negative individuals who had laboratory-confirmed SARS-CoV-2 infection. Methods: We used Cox proportional hazard models to compare the relative risk of hospitalization in PLWH and HIV-negative individuals. Then, we used propensity score weighting to examine the influence of sociodemographic factors and comorbid conditions on risk of hospitalization. These models were further stratified by vaccination status and pandemic period (pre-Omicron: December 15, 2020, to November 21, 2021; Omicron: November 22, 2021, to October 31, 2022). Results: The crude hazard ratio (HR) for risk of hospitalization in PLWH was 2.44 (95% confidence interval [CI]: 2.04-2.94). In propensity score-weighted models that included all covariates, the relative risk of hospitalization was substantially attenuated in the overall analyses (adjusted HR [aHR]: 1.03; 95% CI: 0.85-1.25), in vaccinated (aHR 1.00; 95% CI: 0.69-1.45), inadequately vaccinated (aHR: 1.04; 95% CI: 0.76-1.41) and unvaccinated individuals (aHR: 1.15; 95% CI: 0.84-1.56). Conclusion: PLWH had about two times the risk of COVID-19 hospitalization than HIV-negative individuals in crude analyses which attenuated in propensity score-weighted models. This suggests that the risk differential can be explained by sociodemographic factors and history of comorbidity, underscoring the need to address social and comorbid vulnerabilities (e.g., injecting drugs) that were more prominent among PLWH.

Understanding the roots of Covid-19 vaccine hesitancy in at-risk groups, such as persons living with HIV (PLWH), is of utmost importance. We developed a modified Vaccine Hesitancy Scale (VHS) questionnaire using items from the National Advisory Committee on Immunization Acceptability Matrix. To examine factors associated with receiving COVID-19 vaccine and the link between vaccine attitudes and beliefs with vaccine behavior, PLWH were recruited via social media and community-based organizations (February-May 2022). Descriptive statistics were used to summarize results. Total VHS score was generated by adding Likert scale scores and linear regression models used to compare results between participants who received or did not receive COVID-19 vaccines. Logistic regression models were used to identify factors associated with vaccine uptake. A total of 246 PLWH indicated whether they received a COVID-19 vaccine. 89% received ≥ 1 dose. Mean total VHS(SD) for persons having received ≥ 1 COVID-19 vaccine was 17.8(6.2) vs. 35.4(9.4) for participants not having received any COVID-19 vaccine. Persons who received ≥ 1 dose were significantly older than those who had not received any (48.4 ± 13.8 vs. 34.0 ± 7.7 years, p < 0.0001). The majority of participants considered COVID-19 vaccination important for their health(81.3%) and the health of others(84.4%). Multivariate logistic regression revealed the odds of taking ≥ 1dose were increased 2.4-fold [95% CI 1.6, 3.5] with each increase in age of 10 years (p < 0.0001). Sex and ethnicity were not different between groups. In conclusion, PLWH accept COVID-19 vaccines for both altruistic and individual reasons. With evolving recommendations and increasing numbers of booster vaccines, we must re-examine the needs of PLWH regularly.

Background: Self-report of human papillomavirus (HPV) vaccination has ~80–90% sensitivity and ~75–85% specificity. We measured the effect of nondifferential exposure misclassification associated with self-reported vaccination on vaccine effectiveness (VE) estimates. Methods: Between 2017–2019, we recruited sexually active gay, bisexual, and other men who have sex with men aged 16–30 years in Canada. VE was derived as 1−prevalence ratio × 100% for prevalent anal HPV infection comparing vaccinated (≥1 dose) to unvaccinated men using a multivariable modified Poisson regression. We conducted a multidimensional and probabilistic quantitative bias analysis to correct VE estimates. Results: Bias-corrected VE estimates were relatively stable across sensitivity values but differed from the uncorrected estimate at lower values of specificity. The median adjusted VE was 27% (2.5–97.5th simulation interval = −5–49%) in the uncorrected analysis, increasing to 39% (2.5–97.5th simulation interval = 2–65%) in the bias-corrected analysis. Conclusion: A large proportion of participants erroneously reporting HPV vaccination would be required to meaningfully change VE estimates.

Objectives: Many vaccines require higher/additional doses or adjuvants to provide adequate protection for people with HIV (PWH). Here, we compare coronavirus disease 2019 (COVID-19) vaccine-induced antibody neutralization capacity in PWH vs. HIV-negative individuals following two vaccine doses. Design: In Canadian prospective observational cohorts, including a multicentre study of PWH receiving at least two COVID-19 vaccinations (mRNA or ChAdOx1-S), and a parallel study of HIV-negative controls (Stop the Spread Ottawa Cohort), we measured vaccine-induced neutralization capacity 3 months post dose 2 (±1 month). Methods: COVID-19 neutralization efficiency was measured by calculating the half maximal inhibitory dilution (ID50) using a high-throughput protein-based neutralization assay for Ancestral (Wuhan), Delta and Omicron (BA.1) spike variants. Univariable and multivariable quantile regression were used to compare COVID-19-specific antibody neutralization capacity by HIV status. Results: Neutralization assays were performed on 256 PWH and 256 controls based on specimen availability at the timepoint of interest, having received two vaccines and known date of vaccination. There was a significant interaction between HIV status and previous COVID-19 infection status in median ID50. There were no differences in median ID50 for HIV+ vs. HIV-negative persons without past COVID-19 infection. For participants with past COVID-19 infection, median ICD50 was significantly higher in controls than in PWH for ancestral SARS-CoV-2 and Omicron variants, with a trend for the Delta variant in the same direction. Conclusion: Vaccine-induced SARS-CoV-2 neutralization capacity was similar between PWH vs. HIV-negative persons without past COVID-19 infection, demonstrating favourable humoral-mediated immunogenicity. Both HIV+ and HIV-negative persons demonstrated hybrid immunity. Trial registration: clinicaltrials.gov NCT04894448.

Abstract Introduction People living with HIV (PLWH) and/or who inject drugs may experience lower vaccine effectiveness (VE) against SARS‐CoV‐2 infection. Methods A validated algorithm was applied to population‐based, linked administrative datasets in the British Columbia COVID‐19 Cohort (BCC19C) to ascertain HIV status and create a population of PLWH and matched HIV‐negative individuals. The study population was limited to individuals who received an RT‐PCR laboratory test for SARS‐CoV‐2 between 15 December 2020 and 21 November 2021 in BC, Canada. Any history of injection drug use (IDU) was ascertained using a validated administrative algorithm. We used a test‐negative study design (modified case−control analysis) and multivariable logistic regression to estimate adjusted VE by HIV status and history of IDU. Results Our analysis included 2700 PLWH and a matched population of 375,043 HIV‐negative individuals, among whom there were 351 and 103,049 SARS‐CoV‐2 cases, respectively. The proportion of people with IDU history was much higher among PLWH compared to HIV‐negative individuals (40.7% vs. 4.3%). Overall VE during the first 6 months after second dose was lower among PLWH with IDU history (65.8%, 95% CI = 43.5–79.3) than PLWH with no IDU history (80.3%, 95% CI = 62.7–89.6), and VE was particularly low at 4–6 months (42.4%, 95% CI = −17.8 to 71.8 with IDU history vs. 64.0%; 95% CI = 15.7–84.7 without), although confidence intervals were wide. In contrast, overall VE was 88.6% (95% CI = 88.2–89.0) in the matched HIV‐negative population with no history of IDU and remained relatively high at 4–6 months after second dose (84.6%, 95% CI = 83.8–85.4). Despite different patterns of vaccine protection by HIV status and IDU history, peak estimates were similar (≥88%) across all populations. Conclusions PLWH with a history of IDU may experience lower VE against COVID‐19 infection, although findings were limited by a small sample size. The lower VE at 4–6 months may have implications for booster dose prioritization for PLWH and people who inject drugs. The immunocompromising effect of HIV, substance use and/or co‐occurring comorbidities may partly explain these findings.

BACKGROUND:Real-world evidence of human papillomavirus (HPV) vaccine effectiveness (VE) against longitudinal outcomes is lacking among gay, bisexual, and other men who have sex with men (GBM). We compared 12-month incidence and persistence of anal HPV infection between vaccinated and unvaccinated GBM.METHODS:We recruited GBM aged 16-30 years in Montreal, Toronto, and Vancouver, Canada, from 2017 to 2019. Participants were followed over a median of 12 months (interquartile range, 12-13 months). Participants self-reported HPV vaccination and self-collected anal specimens for HPV DNA testing. We calculated prevalence ratios (PR) for 12-month cumulative incidence and persistence with ≥1 quadrivalent vaccine type (HPV 6/11/16/18) between vaccinated (≥1 dose at baseline) and unvaccinated participants using a propensity score-weighted, modified Poisson regression.RESULTS:Among 248 participants, 109 (44.0%) were vaccinated at baseline, of whom 62.6% received 3 doses. PRs for HPV 6/11/16/18 were 0.56 (95% confidence interval [CI], .24-1.31) for cumulative incidence and 0.53 (95% CI, .25-1.14) for persistence. PRs were 0.23 (95% CI, .05-1.03) and 0.08 (95% CI, .01-.59) for incidence and persistence, respectively, among participants who received their first dose at age ≤23 years and 0.15 (95% CI, .03-.68) and 0.12 (95% CI, .03-.54) among participants who were sexually active for ≤5 years before vaccination.CONCLUSIONS:Findings support national recommendations for HPV vaccination at younger ages or soon after sexual debut.

Background: Starting in 2015/16, most Canadian provinces introduced publicly-funded human papillomavirus (HPV) vaccination programs for gay, bisexual, and other men who have sex with men (GBM) aged ≤ 26 years. We estimated 12-month changes in HPV vaccine coverage among community-recruited GBM from 2017 to 2021 and identified baseline factors associated with vaccine initiation (≥1 dose) or series completion (3 doses) among participants who were unvaccinated or partially vaccinated at baseline. Methods: We recruited sexually-active GBM aged ≥ 16 years in Montreal, Toronto, and Vancouver, Canada, from 02/2017 to 08/2019 and followed them over a median of 12 months (interquartile range = 12–13 months). We calculated the proportion who initiated vaccination (≥1 dose) or completed the series (3 doses) by 12-month follow-up. Analyses were stratified by city and age-eligibility for the publicly-funded programs at baseline (≤26 years or > 26 years). We used multivariable logistic regression to identify baseline factors associated with self-reported incident vaccine initiation or series completion. Results: Among 165 unvaccinated participants aged ≤ 26 years at baseline, incident vaccine initiation (≥1 dose) during follow-up was 24.1% in Montreal, 33.3% in Toronto, and 38.9% in Vancouver. Among 1,059 unvaccinated participants aged > 26 years, incident vaccine initiation was 3.4%, 8.9%, and 10.9%, respectively. Higher education and trying to access pre-exposure prophylaxis for HIV were associated with incident vaccination among those aged ≤ 26 years, while younger age, residing in Vancouver (vs. Montreal), being diagnosed with anogenital warts, having both government and private extended medical insurance, and being vaccinated against influenza were associated with incident vaccination among those aged > 26 years. Conclusions: We observed substantial gains in HPV vaccine coverage among young GBM within 5 + years of targeted program implementation, but gaps remain, particularly among older men who are ineligible for publicly-funded programs. Findings suggest the need for expanded public funding or insurance coverage for HPV vaccines.

OBJECTIVES:Many vaccines require higher/additional doses or adjuvants to provide adequate protection for people with HIV (PWH). Our objective was to compare COVID-19 vaccine immunogenicity in PWH to HIV-negative individuals. DESIGN:In a Canadian multi-center prospective, observational cohort of PWH receiving at least two COVID-19 vaccinations, we measured vaccine-induced immunity at 3 and 6 months post 2nd and 1-month post 3rd doses. METHODS:The primary outcome was the percentage of PWH mounting vaccine-induced immunity [co-positivity for anti-IgG against SARS-CoV2 Spike(S) and receptor-binding domain proteins] 6 months post 2nd dose. Univariable and multivariable logistic regressions were used to compare COVID-19-specific immune responses between groups and within subgroups. RESULTS:Data from 294 PWH and 267 controls were analyzed. Immunogenicity was achieved in over 90% at each time point in both groups. The proportions of participants achieving comparable anti-receptor-binding domain levels were similar between the group at each time point. Anti-S IgG levels were similar by group at month 3 post 2nd dose and 1-month post 3rd dose. A lower proportion of PWH vs. controls maintained vaccine-induced anti-S IgG immunity 6 months post 2nd dose [92% vs. 99%; odds ratio: 0.14 (95% confidence interval: 0.03, 0.80; P = 0.027)]. In multivariable analyses, neither age, immune non-response, multimorbidity, sex, vaccine type, or timing between doses were associated with reduced IgG response. CONCLUSION:Vaccine-induced IgG was elicited in the vast majority of PWH and was overall similar between groups. A slightly lower proportion of PWH vs. controls maintained vaccine-induced anti-S IgG immunity 6 months post 2nd dose demonstrating the importance of timely boosting in this population.

During 2016-2017 and 2017-2018 influenza A(H3N2) epidemics, updated clade 3C.2a vaccine bore egg-adaptation mutations and circulating 3C.2a viruses showed substantial genetic diversity. Vaccine effectiveness by phylogenetic subcluster and prior vaccination history reveal informative heterogeneity underpinning subtype-specific findings. Background The influenza A(H3N2) vaccine was updated from clade 3C.3a in 2015-2016 to 3C.2a for 2016-2017 and 2017-2018. Circulating 3C.2a viruses showed considerable hemagglutinin glycoprotein diversification and the egg-adapted vaccine also bore mutations. Methods Vaccine effectiveness (VE) in 2016-2017 and 2017-2018 was assessed by test-negative design, explored by A(H3N2) phylogenetic subcluster and prior season's vaccination history. Results In 2016-2017, A(H3N2) VE was 36% (95% confidence interval [CI], 18%-50%), comparable with (43%; 95% CI, 24%-58%) or without (33%; 95% CI, -21% to 62%) prior season's vaccination. In 2017-2018, VE was 14% (95% CI, -8% to 31%), lower with (9%; 95% CI, -18% to 30%) versus without (45%; 95% CI, -7% to 71%) prior season's vaccination. In 2016-2017, VE against predominant clade 3C.2a1 viruses was 33% (95% CI, 11%-50%): 18% (95% CI, -40% to 52%) for 3C.2a1a defined by a pivotal T135K loss of glycosylation; 60% (95% CI, 19%-81%) for 3C.2a1b (without T135K); and 31% (95% CI, 2%-51%) for other 3C.2a1 variants (with/without T135K). VE against 3C.2a2 viruses was 45% (95% CI, 2%-70%) in 2016-2017 but 15% (95% CI, -7% to 33%) in 2017-2018 when 3C.2a2 predominated. VE against 3C.2a1b in 2017-2018 was 37% (95% CI, -57% to 75%), lower at 12% (95% CI, -129% to 67%) for a new 3C.2a1b subcluster (n = 28) also bearing T135K. Conclusions Exploring VE by phylogenetic subcluster and prior vaccination history reveals informative heterogeneity. Pivotal mutations affecting glycosylation sites, and repeat vaccination using unchanged antigen, may reduce VE.