Assessing the real-world effectiveness of five SARS-CoV-2 vaccines in a cohort of Mexican pensioners: a nationwide nested test-negative design study

Antibody Response Following COVID-19 Vaccination in Malaysian Cancer Patients and Healthy Individuals

INTRODUCTION

There is a lack of real-world evidence on direct comparisons between COVID-19 vaccines in multiethnic low- and middle-income settings. Cancer patients have an impaired vaccine response due to the disease itself or the effects of treatment. Hence, identifying the best vaccine to use for cancer patients is important. We aimed to compare the antibody response between cancer patients and healthy individuals following COVID-19 vaccination and assess seroconversion rates, vaccine efficacy, and the impact of sex on antibody response, as well as document adverse events in cancer patients.

MATERIALS AND METHODS

A prospective cohort study of cancer patients and healthy individuals receiving vaccines was conducted in Malaysia. All participants were aged 18 or above at recruitment and received at least two doses of vaccine. We excluded patients who had missing serum antibody data post-first dose and post-second dose. Sociodemographic and clinical data were collected at baseline, prior to vaccination. Data on self-reported breakthrough infection was collected at six months. Multivariable linear mixed-effects regression models were used to investigate the association between the type of vaccine and serum IgG titer.

RESULTS

A total of 389 patients with solid (n=276, 71.0%) or hematologic cancers (n=113, 29.0%) were included, along with 246 healthy individuals. Most cancer patients received BNT162b2 (n=358, 92.0%), followed by AZ1222 (n=19, 4.9%) and Coronavac (n=12, 3.1%). Most healthy individuals received BNT162b2 (n=151, 61.4%), followed by Coronavac (n=95, 38.6%). Vaccination, after adjustment for confounders (pre-vaccine infection, age, ethnicity, comorbidity, timepoint, income, cancer type, and booster), with Coronavac was associated with lower log IgG titer (-3.09 U/ml, 95% confidence interval=-4.37 to -1.80, p<0.01) than that of BNT162b2 in patients with cancer and also lower log IgG titer (-2.64 U/ml, 95% confidence interval=-2.97 to -2.30, p<0.01) than that of BNT162b2 in healthy individuals. No effect modification by sex was observed. Among the cancer cohort, 76 patients (19.5%) reported breakthrough infections after vaccination, while 33 (13.4%) participants in the healthy cohort reported breakthrough infections after vaccination. Coronavac was associated with greater odds of breakthrough infection among healthy individuals (odds ratio=7.34 compared to BNT162b2, confidence interval=1.40 to 33.49, p=0.02).

CONCLUSION

Vaccination with BNT162b2 yields higher IgG titer than Coronavac in all groups and fewer breakthrough infections in healthy subjects. The effect of vaccination is not modified by sex.

Receipt of prescription opioid medication is associated with increased mortality in an Israeli population

BACKGROUND

Despite Israel's increased use of prescription opioids, reported deaths resulting or associated with opioids have decreased, in fact dramatically, since 2005. This contrast is unique and difficult to explain. We sought to examine whether higher prescribed opioid dosages among adults without oncologic diagnoses were associated with higher all-cause mortality rates.

METHODS

A historical cohort study in Clalit Health Services, using a data repository including all adult patients prescribed opiates between 2010 and 2020, excluding patients with oncologic diagnoses. Patients were classified into three groups according to opioid use: below 50 Morphine milligram equivalents (MME) per day, 50 to 90 MME per day, and above 90 MME per day. Sex, Charlson comorbidity score, age and socioeconomic status were recorded. Mortality rates were compared between the dosage groups and compared to age-standardized mortality rates in the general population.

RESULTS

On multivariate analysis, patients receiving 90 or more MME per day were 2.37 (95%CI 2.1 to 2.68) more likely to have died compared to patients receiving below 50 MME per day. The respective hazard ratio among patients receiving between 50 and 90 MME per day was 2.23 (2.01 to 2.46). Among patients aged 18 to 50, standardized mortality ratios (SMRs) compared to the general population ranged between 5.4 to 8.6 among women, receiving between 50 and 90 MME per day, and between 8.07 and 10.7 among women receiving 90 or more MME per day. The respective SMRs among men were 1.2 to 3.8 and 2.7 to 5.4.

CONCLUSION

Increased opioid use is independently associated with increased all-cause mortality among non-oncological patients. This result is most notable among young adults with little or no known comorbidities. These findings are consistent with results in other countries and seem more credible than previous Israeli reports. Healthcare regulators and providers should, therefore, act to curtail the increasing opioid prescriptions and devise and enhance controls in the healthcare system, which, until 2020, had very limited mechanisms in place.