Antiplatelet response to clopidogrel is associated with a haplotype in CYP2C19 gene in Pakistani patients.

Clopidogrel, an antiplatelet drug, is frequently prescribed to patients diagnosed with ischemic diseases such as those suffering from acute coronary syndromes or ischemic stroke. Despite the drug being effective in majority of the patients, some still experience ischemic events early in the treatment which might be due to poor platelet inhibition. This study aims to investigate the association of cytochrome P450 2C19 (CYP2C19) loss-of-function polymorphisms, haplotypes as well as a wide range of clinical and demographic variables with platelet aggregation phenotypes to clopidogrel in a Pakistani cohort. The study comprised of a total of 120 patients diagnosed with cardiovascular diseases and were treated with clopidogrel. Antiplatelet response to clopidogrel was monitored by Helena AggRAM (HL-2-1785P) and patients with maximal platelet aggregation more than 50% were categorized as low responders and those with less than 50% as high responders. Our results show that 56.6% of patients were homozygous for the CYP2C19 wild-type allele, 38.3% of patients possessed one copy of the CYP2C19*2 allele and 5% of patients possessed both CYP2C19*2 alleles. No CYP2C19*3 allele was found in our patient cohort. There was no statistically significant difference between the high and low responder groups to clopidogrel in terms of extensive, intermediate and poor metabolizer genotypes. However, haplotype (H1), leukocyte count, random blood glucose, and history of diabetes mellitus was associated with the antiplatelet response to clopidogrel. The prevalence of clopidogrel resistance in our population was in line with that reported for other regional and global populations.

Vaccine Development against COVID-19: Study from Pre-Clinical Phases to Clinical Trials and Global Use.

As per the World Health Organization (WHO), more than 288 vaccines against COVID-19 are being developed, with an estimated 184 being presently investigated in the pre-clinical phases, while 104 of these vaccine candidates are at various stages of clinical trials. Twelve of these are in the advanced stages of clinical investigation, and promising results in the phase 3 trials have already paved the way for their regulatory approval and subsequent dissemination for global use. Preliminary and interim results of some of these candidate vaccines are being analyzed for public dissemination. Some of these vaccines have already been rolled out to immunize not only the highest risk individuals but also the general population in several countries. Once their safety and efficacy are established, the next limiting step would be their mass manufacturing by the pharmaceutical companies to fulfill the global demand. The challenge of manufacturing billions of doses of high-quality vaccines is under-appreciated at the moment. A massive vaccination drive would be needed to protect people of all ages. The timely and coordinated execution of the vaccination effort would require unprecedented coordination at the national and international levels for generating funds to purchase the required doses of vaccines, fair distribution of doses and managing the mechanics of delivering vaccines throughout the world.