Evaluating real-world COVID-19 vaccine effectiveness using a test-negative case-control design

COVID-19 vaccine hesitancy: assessing the prevalence, predictors, and effectiveness of a community pharmacy based counseling intervention

BACKGROUND

Coronavirus disease (COVID-19) vaccine hesitancy is a global challenge. In low- and middle-income countries (LMICs), the problem has persisted despite vaccine availability and decreasing infections. In Uganda, there is still limited information on the extent and predictors of vaccine hesitancy. This study sought to assess the prevalence and predictors of COVID-19 vaccine hesitancy, and the effectiveness of an intervention that involved community pharmacy counseling in combating COVID-19 vaccine hesitancy.

METHODS

A total of 394 participants were enrolled in a 4-week prospective cohort interventional study. The study was conducted across eight community pharmacies in Mbarara City, between 9:00 AM and 5:00 PM daily. The study personnel ascertained the vaccination status of all clients seeking community pharmacy services. All unvaccinated clients were consecutively assessed for eligibility, and eligible clients were systematically enrolled after receiving the community pharmacy services for which they requested. The study intervention involved structured participant counseling (within the pharmacy premise), follow-up short message service (weekly), and telephone calls (bi-weekly). Only participants who did not accept to receive the COVID-19 vaccine despite counseling were followed up for four weeks, or until they accepted to receive a COVID-19 vaccine. The effectiveness of the community pharmacy counseling intervention was determined as an increase in COVID-19 vaccine acceptance, and desirable attitudinal change towards COVID-19 disease, vaccination exercise, and vaccines. Descriptive analysis was used to summarize data, and multivariate analysis was used to determine the predictors of COVID-19 vaccine hesitancy. A p-value < 0.05 was considered statistically significant.

RESULTS

Out of 394 participants, 221 (56%) were hesitant to receive a COVID-19 vaccine. Participants expressed several reasons (mean 2±1) for COVID-19 vaccine hesitancy, mostly concerning vaccine safety (N=160, 47.3%). The overall COVID-19 vaccine acceptance rate increased by 25.4 percent points (43.9 - 69.3 percent points) after the study intervention. Age, religion, level of education, distance from the nearest public health facility, having a friend/family diagnosed with COVID-19, and personal suspicion of contracting COVID-19 were significant predictors of COVID-19 vaccine hesitancy.

CONCLUSION

COVID-19 vaccine hesitancy is a big challenge in Uganda. A mix of sociodemographic and COVID-19 vaccine perceptions are the key predictors of COVID-19 vaccine hesitancy. Although COVID-19 vaccines were not available at the time of the study, this study found that structured counseling interventions can improve COVID-19 vaccine acceptance rates. Larger prospective studies should evaluate the effectiveness of similar interventions in community pharmacies and other healthcare settings.

Daily COVID-19 symptom assessment over 28 days - findings from a daily direct-to-patient registry of COVID-19 positive patients

In January 2021, 999 COVID-19 positive adults in the US enrolled in an online, direct-to-patient registry to describe daily symptom severity and progression over 28 days. The most commonly reported and persistent symptoms were fatigue, headache, decreased sense of taste, decreased sense of smell, and cough. Fast resolving symptoms included gastrointestinal symptoms (nausea, vomiting, diarrhea) and those related to fever and chills. While more than half (56%) of patients reported overall symptom improvement during the 28-day study period, 60% of patients were still reporting at least 1 COVID-19 symptom at the end of 28 days. Risk factors for experiencing symptoms for longer duration included at least one of the following: older age (> 60 years), higher BMI, lung disease, and receiving medication for hypertension. The study demonstrates the value of patient-reported data to provide important and timely insights to COVID-19 disease and symptom progression and the potential of using real-world data to inform clinical trial design and endpoints.

M, Armas R, de Mora D, Pinos J, Olmedo A, Salas R, Jimbo-Sotomayor R, Chiluisa C, Acosta P, Sánchez X, Whittembury A. Effectiveness of COVID-19 vaccines in Ecuador: A test-negative design

Background

The COVID-19 pandemic poses a significant global health threat, characterized by high morbidity, severity, and the emergence of concerning variants. Latin America has been greatly affected, with high infection and mortality rates. Vaccination plays a crucial role in mitigating severe disease and controlling the pandemic. This study aims to assess the effectiveness of COVID-19 vaccines in preventing SARS-CoV-2 severe acute respiratory infections (SARI) in hospitalized vaccination target groups in Ecuador.

Methods

This is a test-negative design study. We used data reported through sentinel surveillance of SARI between May 2021 and March 2022 in Ecuador. Patients with case criteria of SARI and hospitalized for a minimum of 24 hours were included in the study. Cases were defined as patients with SARI with a positive RT-qPCR test for SARS-CoV-2 and controls were those with a negative result. Information on vaccination status was obtained from the national vaccination registry, a valid dose of vaccination was considered when it was administered at least 14 days prior to symptom onset. Vaccine effectiveness (VE) (1-OR/OR) was calculated using a logistic regression.

Results

A total of 1,277 patients were included in the analysis of VE. The adjusted vaccine effectiveness (aVE) in preventing hospitalization, adjusted for sex, age group, presence of one or more comorbidities, and period of the predominance of the omicron variant, was 44.5% for the partial primary schedule, 74.7% for the complete primary schedule, and 79.9% for the complete primary schedule plus booster doses. The aVE in avoiding ICU admissions was close to 80% with both the complete primary schedule and the booster doses, and in avoiding deaths, the aVE was 89% and 98%, respectively.

Conclusions

In Ecuador, COVID-19 vaccination prevents hospitalizations, ICU admissions, and deaths. The effectiveness of the vaccines improves with more doses, offering increased protection across all age groups.

Tactical Considerations for Designing Real-World Studies: Fit-for-Purpose Designs That Bridge Research and Practice

Real-world evidence (RWE) is being used to provide information on diverse groups of patients who may be highly impacted by disease but are not typically studied in traditional randomized clinical trials (RCT) and to obtain insights from everyday care settings and real-world adherence to inform clinical practice. RWE is derived from so-called real-world data (RWD), ie, information generated by clinicians in the course of everyday patient care, and is sometimes coupled with systematic input from patients in the form of patient-reported outcomes or from wearable biosensors. Studies using RWD are conducted to evaluate how well medical interventions, services, and diagnostics perform under conditions of real-world use, and may include long-term follow-up. Here, we describe the main types of studies used to generate RWE and offer pointers for clinicians interested in study design and execution. Our tactical guidance addresses (1) opportunistic study designs, (2) considerations about representativeness of study participants, (3) expectations for transparency about data provenance, handling and quality assessments, and (4) considerations for strengthening studies using record linkage and/or randomization in pragmatic clinical trials. We also discuss likely sources of bias and suggest mitigation strategies. We see a future where clinical records - patient-generated data and other RWD - are brought together and harnessed by robust study design with efficient data capture and strong data curation. Traditional RCT will remain the mainstay of drug development, but RWE will play a growing role in clinical, regulatory, and payer decision-making. The most meaningful RWE will come from collaboration with astute clinicians with deep practice experience and questioning minds working closely with patients and researchers experienced in the development of RWE.

Measuring the Effectiveness of COVID-19 Vaccines Used during a Surge of the Delta Variant of SARS-CoV-2 in Bangladesh: A Test-Negative Design Evaluation

BACKGROUND

From May to December 2021, Bangladesh experienced a major surge in the Delta variant of SARS-CoV-2. The earlier rollout of several vaccines offered the opportunity to evaluate vaccine effectiveness against this variant.

METHODS

A prospective, test-negative case-control study was conducted in five large hospitals in Dhaka between September and December 2021. The subjects were patients of at least 18 years of age who presented themselves for care, suffering COVID-like symptoms of less than 10 days' duration. The cases had PCR-confirmed infections with SARS-CoV-2, and up to 4 PCR test-negative controls were matched to each case, according to hospital, date of presentation, and age. Vaccine protection was assessed as being the association between the receipt of a complete course of vaccine and the occurrence of SARS-CoV-2 disease, with symptoms beginning at least 14 days after the final vaccine dose.

RESULTS

In total, 313 cases were matched to 1196 controls. The genotyping of case isolates revealed 99.6% to be the Delta variant. Receipt of any vaccine was associated with 12% (95% CI: -21 to 37, p = 0.423) protection against all episodes of SARS-CoV-2. Among the three vaccines for which protection was evaluable (Moderna (mRNA-1273); Sinopharm (Vero Cell-Inactivated); Serum Institute of India (ChAdOx1 nCoV-19)), only the Moderna vaccine was associated with significant protection (64%; 95% CI: 10 to 86, p = 0.029). Protection by the receipt of any vaccine against severe disease was 85% (95% CI: 27 to 97, p = 0.019), with protection estimates of 75% to 100% for the three vaccines.

CONCLUSIONS

Vaccine protection against COVID-19 disease of any severity caused by the Delta variant was modest in magnitude and significant for only one of the three evaluable vaccines. In contrast, protection against severe disease was high in magnitude and consistent for all three vaccines. Because our findings are not in complete accord with evaluations of the same vaccines in more affluent settings, our study underscores the need for country-level COVID-19 vaccine evaluations in developing countries.