StockMarketWire.com - UK stocks opened lower on Friday after Donald Trump tested positive for Covid-19, adding an extra element of political uncertainty in the US just a month before the presidential election.

At 0828, the benchmark FTSE 100 index was down 36.59 points, or 0.6%, at 5,842.86.

Trump, 74, and first lady Melania Trump both had contracted Covid-19 and put themselves in quarantine. They were tested after close aide Hope Hicks tested positive for the disease.

In corporate news, gold miner Centamin sank 19% to 162.32p as it downgraded its production guidance, having deferred mining operations at its Sukari project in Egypt after it detected movement in waste material.

Centamin said production for the fourth quarter would fall to about 70,000 ounces.

Pharmaceutical company AstraZeneca shed 0.8% to £84.15, even as its diabetes drug was granted breakthrough therapy designation in the US to treat patients with chronic kidney disease with and without type-2 diabetes.

Cancer and infectious diseases focused Scancell jumped 13% to 18.98p on announcing that it had chosen Cobra Biologics to manufacture its Covid-19 vaccine.

A collaboration agreement between the companies covered production of plasmid DNA needed to generate the DNA-based vaccine against SARS-CoV-2, for use in a phase-one clinical trial in 2021.

Fellow pharmaceutical company Ovoca Bio tumbled 25% to 10.02p after Russian regulators rejected its marketing authorisation request for a treatment for decreased sexual desire in women, administered by nasal spray.

Ovoca Bio said the Russian Ministry of Health had identified 'certain issues relating to the chemistry, manufacturing and controls and labelling sections of the marketing authorisation submission dossier'.

No safety or efficacy issues were raised, said the company, which added that it was working to address the regulator's concerns.

Marine contractor James Fisher and Sons fell 0.7% to £11.3656, despite winning a multi-million-pound five-year service contract from the UK's Royal Navy to ensure the operational readiness of its life-support diving equipment.

Logistics company Wincanton rallied 6.6% to 226p as it stuck by its recently upgraded annual profit guidance and said it had made a new pension agreement that included a reduced deficit.

In a trading update for the six months through September, Wincanton said its guidance outlined on 9 September for results in the current year to be 'materially ahead' of market expectations remained unchanged.

Media platform Future added 0.5% to £19.6172 following news that it had acquired US-based digital entertainment publisher CinemaBlend, for an undisclosed sum.

CinemaBlend provided a discussion platform for films and TV shows, both on streaming services such as Netflix and linear TV such as HBO.

Regional office and industrial property investor Regional REIT was unchanged at 65.5p after it sold the Juniper Park industrial warehouse in Basildon for £32.7 million.

The sale price reflected an uplift of 59% from the acquisition price, including subsequent capital expenditure, and 3.9% above the 30 June 2020 valuation.

Story provided by StockMarketWire.com