SARS-CoV-2 vaccination and myocarditis or myopericarditis:population based cohort study

OBJECTIVE: To investigate the association between SARS-CoV-2 vaccination and myocarditis or myopericarditis. DESIGN: Population based cohort study. SETTING: Denmark. PARTICIPANTS: 4 931 775 individuals aged 12 years or older, followed from 1 October 2020 to 5 October 2021. MAIN OUTCOME MEASURES: The primary outcome, myocarditis or myopericarditis, was defined as a combination of a hospital diagnosis of myocarditis or pericarditis, increased troponin levels, and a hospital stay lasting more than 24 hours. Follow-up time before vaccination was compared with follow-up time 0-28 days from the day of vaccination for both first and second doses, using Cox proportional hazards regression with age as an underlying timescale to estimate hazard ratios adjusted for sex, comorbidities, and other potential confounders. RESULTS: During follow-up, 269 participants developed myocarditis or myopericarditis, of whom 108 (40%) were 12-39 years old and 196 (73%) were male. Of 3 482 295 individuals vaccinated with BNT162b2 (Pfizer-BioNTech), 48 developed myocarditis or myopericarditis within 28 days from the vaccination date compared with unvaccinated individuals (adjusted hazard ratio 1.34 (95% confidence interval 0.90 to 2.00); absolute rate 1.4 per 100 000 vaccinated individuals within 28 days of vaccination (95% confidence interval 1.0 to 1.8)). Adjusted hazard ratios among female participants only and male participants only were 3.73 (1.82 to 7.65) and 0.82 (0.50 to 1.34), respectively, with corresponding absolute rates of 1.3 (0.8 to 1.9) and 1.5 (1.0 to 2.2) per 100 000 vaccinated individuals within 28 days of vaccination, respectively. The adjusted hazard ratio among 12-39 year olds was 1.48 (0.74 to 2.98) and the absolute rate was 1.6 (1.0 to 2.6) per 100 000 vaccinated individuals within 28 days of vaccination. Among 498 814 individuals vaccinated with mRNA-1273 (Moderna), 21 developed myocarditis or myopericarditis within 28 days from vaccination date (adjusted hazard ratio 3.92 (2.30 to 6.68); absolute rate 4.2 per 100 000 vaccinated individuals within 28 days of vaccination (2.6 to 6.4)). Adjusted hazard ratios among women only and men only were 6.33 (2.11 to 18.96) and 3.22 (1.75 to 5.93), respectively, with corresponding absolute rates of 2.0 (0.7 to 4.8) and 6.3 (3.6 to 10.2) per 100 000 vaccinated individuals within 28 days of vaccination, respectively. The adjusted hazard ratio among 12-39 year olds was 5.24 (2.47 to 11.12) and the absolute rate was 5.7 (3.3 to 9.3) per 100 000 vaccinated individuals within 28 days of vaccination. CONCLUSIONS: Vaccination with mRNA-1273 was associated with a significantly increased risk of myocarditis or myopericarditis in the Danish population, primarily driven by an increased risk among individuals aged 12-39 years, while BNT162b2 vaccination was only associated with a significantly increased risk among women. However, the absolute rate of myocarditis or myopericarditis after SARS-CoV-2 mRNA vaccination was low, even in younger age groups. The benefits of SARS-CoV-2 mRNA vaccination should be taken into account when interpreting these findings. Larger multinational studies are needed to further investigate the risks of myocarditis or myopericarditis after vaccination within smaller subgroups

Association between Human Papillomavirus Vaccination and Primary Ovarian Insufficiency in a Nationwide Cohort

IMPORTANCE: Anecdotal case reports have suggested an association between human papillomavirus (HPV) vaccination and primary ovarian insufficiency, but observational studies of HPV and primary ovarian insufficiency are rare, and their findings do not support an association. However, available studies have been limited by statistical power, and concerns about infertility after vaccination are associated with lower levels of uptake of the cancer-preventing vaccine in many countries. OBJECTIVE: To evaluate the risk of primary ovarian insufficiency after quadrivalent human papillomavirus (4HPV) vaccination. DESIGN, SETTING, AND PARTICIPANTS: This retrospective cohort study with follow-up from 2007 to 2016 used nationwide data for 996 300 Danish-born girls and women aged 11 to 34 years. Cox proportional hazards regression was used to estimate hazard ratios (HRs) of primary ovarian insufficiency diagnoses by 4HPV vaccination status with adjustment for age, calendar period, and a propensity score summarizing health care use. Data were analyzed from October 2020 to January 2021. EXPOSURES: Receiving 4HPV vaccination compared with receiving no vaccination. MAIN OUTCOMES AND MEASURES: The main outcome was hospital contacts for primary ovarian insufficiency, and the main outcome measures were HRs comparing rates of primary ovarian insufficiency among vaccinated and unvaccinated individuals. RESULTS: During 6 781 166 person-years of follow-up among 996 300 girls and women aged 11 to 34 years (505 829 vaccinated individuals [50.8%] and 490 471 unvaccinated individuals [49.2%]), 144 individuals were diagnosed with primary ovarian insufficiency, including 54 individuals diagnosed after 4HPV vaccination. The median (interquartile range) age of primary ovarian insufficiency diagnosis was 26.94 (12.68) years. The adjusted HR of primary ovarian insufficiency comparing 4HPV vaccination to no vaccination was 0.96 (95% CI, 0.55-1.68). CONCLUSIONS AND RELEVANCE: This study found no association between HPV vaccination and primary ovarian insufficiency. However, given the rarity of the outcome in this study, the presence of a clinically relevant increase in rate of diagnosis cannot be excluded

Comparative effectiveness of bivalent BA.4-5 and BA.1 mRNA booster vaccines among adults aged?50 years in Nordic countries : nationwide cohort study

OBJECTIVE To estimate the effectiveness of the bivalent mRNA booster vaccines containing the original SARS-CoV-2 and omicron BA.4-5 or BA.1 subvariants as the fourth dose against severe covid-19. DESIGN Nationwide cohort analyses, using target trial emulation. SETTING Denmark, Finland, Norway, and Sweden, from 1 July 2022 to 10 April 2023. PARTICIPANTS People aged a50 years who had received at least three doses of covid-19 vaccine (that is, a primary course and a first booster). MAIN OUTCOME MEASURES The Kaplan-Meier estimator was used to compare the risk of hospital admission and death related to covid-19 in people who received a bivalent Comirnaty (Pfizer-BioNTech) or Spikevax(Moderna) BA.4-5 or BA.1 mRNA booster vaccine as a fourth dose (second booster) with three dose (first booster) vaccinated people and between four dose vaccinated people. RESULTS A total of 1 634 199 people receiving bivalent BA.4-5 fourth dose booster and 1 042 124 receiving bivalent BA.1 fourth dose booster across the four Nordic countries were included. Receipt of a bivalent BA.45 booster as a fourth dose was associated with a to hospital with covid-19 of 67.8% (95% confidence interval 63.1% to 72.5%) and a risk difference of-91.9 (95% confidence interval-152.4 to-31.4) per 100 000 people at three months of follow-up compared with having received three doses of vaccine (289 v 893 events). The corresponding comparative vaccine effectiveness and risk difference for bivalent BA.1 boosters (332 v 977 events) were 65.8% (59.1% to 72.4%) and-112.9 (-179.6 to-46.2) per 100 000, respectively. Comparative vaccine effectiveness and risk difference against covid-19 related death were 69.8% (52.8% to 86.8%) and-34.1 (-40.1 to-28.2) per 100 000 for bivalent BA.4-5 booster (93 v 325 events) and 70.0% (50.3% to 89.7%) and-38.7 (-65.4 to-12.0) per 100 000 for BA.1 booster (86 v 286) as a fourth dose. Comparing bivalent BA.4-5 and BA.1 boosters as a fourth dose directly resulted in a three month comparative vaccine effectiveness and corresponding risk difference of-14.9% (-62.3% to 32.4%) and 10.0 (-14.4 to 34.4) per 100 000 people for admission to hospital with covid-19 (802 v 932 unweighted events) and-40.7% (-123.4% to 42.1%) and 8.1 (-3.3 to 19.4) per 100 000 for covid-19 related death (229 v 243 unweighted events). The comparative vaccine effectiveness did not differ across sex and age (70 years) and seemed to be sustained up to six months from the day of vaccination with modest waning. CONCLUSION Vaccination with bivalent BA.4-5 or BA.1 mRNA booster vaccines as a fourth dose was associated with reduced rates of covid-19 related hospital admission and death among adults aged a50 years. The protection afforded by the bivalent BA.4-5 and BA.1 boosters did not differ significantly when directly compared, and any potential difference would most likely be very small in absolute numbers.Peer reviewe

Analysis of Thromboembolic and Thrombocytopenic Events After the AZD1222, BNT162b2, and MRNA-1273 COVID-19 Vaccines in 3 Nordic Countries

IMPORTANCE: Vaccinations are paramount to halt the COVID-19 pandemic, and safety data are essential to determine the risk-benefit ratio of each COVID-19 vaccine. OBJECTIVE: To evaluate the association between the AZD1222, BNT162b2, and mRNA-1273 vaccines and subsequent thromboembolic and thrombocytopenic events. DESIGN, SETTING, AND PARTICIPANTS: This self-controlled case series used individual-level data from national registries in Norway, Finland, and Denmark. Participants included individuals with hospital contacts because of coronary artery disease, coagulation disorders, or cerebrovascular disease between January 1, 2020, and May 16, 2021. EXPOSURES: AZD1222, BNT162b2, or mRNA-1273 vaccine. MAIN OUTCOMES AND MEASURE: Relative rate (RR) of hospital contacts for coronary artery disease, coagulation disorders, or cerebrovascular disease in a 28-day period following vaccination compared with the control period prior to vaccination. RESULTS: We found 265 339 hospital contacts, of whom 112 984 [43%] were for female patients, 246 092 [93%] were for patients born in 1971 or earlier, 116 931 [44%] were for coronary artery disease, 55 445 [21%] were for coagulation disorders, and 92 963 [35%] were for cerebrovascular disease. In the 28-day period following vaccination, there was an increased rate of coronary artery disease following mRNA-1273 vaccination (RR, 1.13 [95% CI, 1.02-1.25]), but not following AZD1222 vaccination (RR, 0.92 [95% CI, 0.82-1.03]) or BNT162b2 vaccination (RR, 0.96 [95% CI, 0.92-0.99]). There was an observed increased rate of coagulation disorders following all 3 vaccines (AZD1222: RR, 2.01 [95% CI, 1.75-2.31]; BNT162b2: RR, 1.12 [95% CI, 1.07-1.19]; and mRNA-1273: RR, 1.26 [95% CI, 1.07-1.47]). There was also an observed increased rate of cerebrovascular disease following all 3 vaccines (AZD1222: RR, 1.32 [95% CI, 1.16-1.52]; BNT162b2: RR, 1.09 [95% CI, 1.05-1.13]; and mRNA-1273: RR, 1.21 [95% CI, 1.09-1.35]). For individual diseases within the main outcomes, 2 notably high rates were observed: 12.04 (95% CI, 5.37-26.99) for cerebral venous thrombosis and 4.29 (95% CI, 2.96-6.20) for thrombocytopenia, corresponding to 1.6 (95% CI, 0.6-2.6) and 4.9 (95% CI, 2.9-6.9) excess events per 100 000 doses, respectively, following AZD1222 vaccination. CONCLUSIONS AND RELEVANCE: In this self-controlled case series, there was an increased rate of hospital contacts because of coagulation disorders and cerebrovascular disease, especially for thrombocytopenia and cerebral venous thrombosis, following vaccination with AZD1222. Although increased rates of several thromboembolic and thrombocytopenic outcomes following BNT162b2 and mRNA-1273 vaccination were observed, these increases were less than the rates observed after AZD1222, and sensitivity analyses were not consistent. Confirmatory analysis on the 2 mRNA vaccines by other methods are warranted

Comparative effectiveness of heterologous third dose vaccine schedules against severe covid-19 during omicron predominance in Nordic countries : population based cohort analyses

OBJECTIVETo investigate the comparative vaccine effectiveness of heterologous booster schedules (ie, three vaccine doses) compared with primary schedules (two vaccine doses) and with homologous mRNA vaccine booster schedules (three vaccine doses) during a period of omicron predominance.DESIGNPopulation based cohort analyses.SETTINGDenmark, Finland, Norway, and Sweden, 27 December 2020 to 31 December 2022.PARTICIPANTSAll adults aged 218 years who had received at least a primary vaccination schedule of AZD1222 (OxfordAstraZeneca) or monovalent SARS-CoV-2 wild type (ancestral) strain based mRNA vaccines BNT162b2 (Pfizer-BioNTech) or mRNA-1273 (Moderna), in any combination.MAIN OUTCOME MEASURESThe main outcome measure was country combined risks of covid-19 related hospital admission and death with covid-19 and additional outcomes of covid-19 related admission to an intensive care unit and SARS-CoV-2 infection. During a period of omicron predominance, these outcomes were compared in those who received a heterologous booster versus primary schedule (matched analyses) and versus those who received a homologous mRNA vaccine booster (weighted analyses). Follow-up was for 75 days from day 14 after the booster dose; comparative vaccine effectiveness was calculated as 1-risk ratio.RESULTSAcross the four Nordic countries, 1 086 418 participants had received a heterologous booster schedule of AZD1222+BNT162b2 or mRNA-1273 and 2 505 093 had received a heterologous booster schedule of BNT162b2+mRNA-1273. Compared with the primary schedule only (two doses), the vaccine effectiveness of heterologous booster schedules comprising AZD1222+BNT162b2 or mRNA-1273 and BNT162b2+mRNA-1273 was 82.7% (95% confidence interval 77.1% to 88.2%) and 81.5% (78.9% to 84.2%) for covid-19 related hospital admission and 95.9% (91.6% to 100.0%) and 87.5% (82.5% to 92.6%) for death with covid-19, respectively. Homologous mRNA booster schedules were similarly associated with increased protection against covid-19 related hospital admission (276.5%) and death with covid-19 (284.1%) compared with previous primary course vaccination only. When a heterologous booster schedule was compared with the homologous booster schedule, vaccine effectiveness was 27.2% (3.7% to 50.6%) for AZD1222+BNT162b2 or mRNA-1273 and 23.3% (15.8% to 30.8%) for BNT162b2+mRNA-1273 schedules against covid-19 related hospital admission and 21.7% (-8.3% to 51.7%) and 18.4% (-15.7% to 52.5%) against death with covid-19, respectively.CONCLUSIONHeterologous booster schedules are associated with increased protection against severe, omicron related covid-19 outcomes compared with primary course schedules and homologous booster schedules.Peer reviewe