Oct 12 (Reuters) - CureVac NV (5CV.DE) said on Tuesday it will give up on its first-generation COVID-19 vaccine candidate and instead focus on collaborating with GSK (GSK.L) to develop improved mRNA vaccine technology. The German biotechnology company"s shares were off about 8% after earlier plunging as much as 13%, hitting their lowest since going public in August last year. CureVac said it would abandon its application for approval from the European Medicines Agency for its first COVID-19 vaccine candidate, CVnCoV, after late-stage trials delivered disappointing results in June with 47% efficacy. Abandoning the vaccine will avoid a potential overlap with approval timelines for its most advanced second-generation candidates, it said. The move also allows the company to focus on the race for new variant-specific vaccines, and for combination shots that prevent two or more infectious diseases. That will also see it try a technology employed by more successful rival BioNTech SE , which modified the nucleosides - the molecules that determine the mRNA’s genetic code - to shield the vaccine against immune system attacks. CureVac had previously banked on non-modified mRNA. The earliest potential approval of CVnCoV would have come in the second quarter of 2022, when candidates from the second-generation vaccine programme were expected to progress to late-stage clinical development, CureVac said. "In the ongoing transition from acute pandemic to endemic, our decision ... reflects expected changes in public health needs that our second generation can potentially address,” said Chief Executive Franz-Werner Haas. The agreement CureVac signed to sell shots to the European Union will end, with no obligation to repay the 450 million euros ($519 million) received from the bloc, the company said. The EU commission did not immediately reply to a request for comment on refunding clauses in the contract. Financial commitments to contract manufacturers would be made public over the next few weeks, but any such burdens were minor, Haas said on call with reporters. CureVac cancelled deals last month with two prospective contractors to make CVnCoV. It said it would seek to repurpose the remaining infrastructure for future products. read more Human trials for its second-generation shot could start in coming months, with any regulatory approval seen in 2022. Animal trials so far showed them to be superior to CureVac"s original COVID-19 vaccine. read more The shot is the latest casualty in the drug industry"s race to develop a vaccine against the coronavirus, which has killed more than 5 million people and infected more than 238 million. French drugmaker Sanofi SA (SASY.PA) also dropped plans for its own mRNA-based COVID-19 vaccine last month because of the dominance achieved by BioNTech with U.S. partner Pfizer Inc (PFE.N) and Moderna Inc (MRNA.O) with shots using the technology. read more Instead, it will pursue the technology, acquired as part of its takeover of Translate Bio , in potential vaccines against influenza and other diseases. ($1 = 0.8670 euros) Reporting by Zuzanna Szymanska, Josephine Mason, Ludwig Burger and Francesco Guarascio; Editing by Louise Heavens, Edmund Blair and Bill Berkrot Our Standards: The Thomson Reuters Trust Principles.