LONDON (Reuters Breakingviews) - RICHER PICKINGS. The UK’s drive to lure homegrown companies to the London Stock Exchange has suffered another snub. Vaccitech, which owns the technology behind AstraZeneca’s Covid-19 jab, has confidentially filed for an initial public offering in the United States, the Financial Times reported on Wednesday. The loss-making Oxford-based startup’s vaccine technology and immunotherapy treatments for cancers could entice U.S. money managers who are used to focusing on drug pipelines. Nevertheless, it’s a high-profile setback for Rishi Sunak, Britain’s finance minister, who has promised to make it easier for companies to sell less than 25% of their shares and let founders keep control when going public. The UK government last year gave Vaccitech a grant to support its research. With used-car seller Cazoo merging with a U.S.-listed blank-cheque company, and private members’ club Soho House also heading for a New York float, Sunak’s campaign to revive the City of London could do with a shot in the arm. (By Aimee Donnellan)