Efficacy of COVID-19 vaccines by race and ethnicity

OBJECTIVES

Vaccine uptake amongst ethnic minority populations has been persistently lower, which may be because of socio-economic factors such as health literacy and health insurance status. This review aimed to assess to what extent COVID-19 clinical trials have considered the impact of race and ethnicity on COVID-19 vaccine safety and efficacy.

STUDY DESIGN

This was a systematic review.

METHODS

Data regarding ethnicity in COVID-19 vaccine clinical trials were systematically reviewed according to Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines in this systematic review, which ran from inception until June 2021. Three international databases, PubMed, Scopus and Web of Science, were used to conduct systematic article searches. Only two studies reported vaccine efficacy among ethnic minority groups.

RESULTS

The efficacy of the mRNA-1273 vaccine was confirmed to be 95% in Caucasians and 97.5% in 'people of colour' in a study by Baden et al. In another study by Polack et al., BNT162b2 mRNA vaccine efficacy was reported to be 95.2% in Caucasians, 100% in Afro-Caribbean or African Americans, 94.2% in Hispanic or Latinx and 95.4% in non-Hispanic, non-Latinx people.

CONCLUSIONS

Given the highly differing effect of COVID-19 on the Afro-Caribbean, Hispanic and South Asian populations, it is imperative for COVID-19 vaccine clinical trials to thoroughly assess the safety and efficacy of vaccines in different ethnicities and, if necessary, develop ethnicity-specific protocols, which can minimise the disproportionate effect of COVID-19 on ethnic minority populations.

P5308Mediterranean-style diet for the primary and secondary prevention of cardiovascular disease: Cochrane systematic review and meta-analysis of randomised clinical trials

Background

Observational studies have confirmed the benefits of adherence to a Mediterranean dietary pattern on cardiovascular disease (CVD) but the randomised controlled trial (RCT) evidence is limited.

Objective

To determine the effectiveness of a Mediterranean-style diet for the primary and secondary prevention of CVD.

Methods

We searched the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, Web of Science, DARE, HTA, NHS EED and trial registers (September 2018). We selected RCTs in healthy adults and adults at high risk of CVD (primary prevention) and those with established CVD (secondary prevention). Both of the following key components were required for our definition of a Mediterranean-style diet: high monounsaturated/saturated fat ratio and a high intake of plant based foods, including fruits, vegetables, and legumes. The intervention could be dietary advice, provision of relevant foods or both. The comparison group received either no intervention, minimal intervention, usual care or another dietary intervention. Outcomes included clinical events and CVD risk factors. We included only studies with follow-up periods of 3 months or more.

Results

Overall, 30 RCTs (12,461 participants randomised) and 7 ongoing trials met our inclusion criteria, whereas 22 primary prevention trials and 6 secondary prevention trials were analysed. Low quality evidence shows little or no effect of the PREDIMED (7747 randomised) intervention (advice to follow a Mediterranean diet plus supplemental extra virgin olive oil or tree nuts) compared to a low fat diet on CVD mortality (HR 0.81 (95% CI 0.5, 1.32)) or total mortality (HR 1.0 (95% CI 0.81, 1.24)) over 4.8 years. There was however a reduction in the number of strokes with the PREDIMED intervention (HR 0.6 (95% CI 0.45, 0.8), moderate quality evidence). For secondary prevention, in the Lyon Diet Heart Study (605 CVD patients), there was moderate quality evidence of a reduction in CVD mortality (HR 0.35 (95% CI 0.15, 0.82)) and total mortality (HR 0.44 (95% CI 0.21, 0.92)) with the intervention, over 46 months. For CVD risk factors, in primary prevention trials, there was low quality evidence for a possible small reduction in total cholesterol (−0.16 mmol/L (95% CI −0.32, 0.00), and moderate quality evidence for a reduction in SBP (−2.99 mmHg (95% CI −3.45, −2.53)) and DBP (−2.0 mmHg (95% CI −2.29, −1.71)). In secondary prevention trials, there was moderate quality evidence of no effect of a Mediterranean-style diet on lipid levels and low or very low quality evidence for blood pressure.

Conclusions

Despite the relatively large number of studies included in this review, there is still some uncertainty regarding the effects of a Mediterranean-style diet on clinical endpoints and CVD risk factors for both primary and secondary prevention. The ongoing studies may provide more certainty in the future.