Oct 27 (Reuters) - Moderna Inc"s (MRNA.O) COVID-19 vaccine could start to be used in children and teens in the United States within weeks, its chief executive said in an interview ahead of the Reuters Total Health conference, which will run virtually from Nov. 15-18. Moderna CEO Staphane Bancel said based on dialogue with the U.S. Food and Drug Administration, he believes his company"s COVID-19 vaccine will be authorized for 12- to 17-year-olds in the next few weeks. Moderna plans to apply for separate U.S. regulatory clearance in children ages 6 through 11 "very soon," Bancel said, adding that he is hopeful that age group could start receiving Moderna"s shots by the end of this year. "It"s entirely possible that this side of Christmas, 6 to 11 years of age would have access to Moderna"s vaccine," Bancel told Reuters. [See link to all Reuters Total Health interviews here: https://reutersevents.com/events/healthcare/]Moderna expects to publish data from its vaccine study of children as young as 6 months to 6 years by the end of this year or early in 2022, Bancel said. Moderna applied for U.S. authorization of its shot for those aged 12 to 17 in June. It published positive data from a clinical trial in children ages 6 to 11 this week, but has not yet submitted an application to regulators for that age group. While children becoming seriously ill or dying from COVID-19 is relatively rare compared with adults, some develop complications, and infections in unvaccinated kids have risen due to the easily transmitted Delta variant of the coronavirus. On Tuesday, a panel of advisers to the FDA backed the use of Pfizer"s shot in children ages 5 to 11. That still needs authorization from the FDA and U.S. Centers for Disease Control and Prevention. ANNUAL BOOSTER SHOTS? The Delta variant has contributed to a global spike in coronavirus cases in recent months, and several countries have begun administering vaccine booster shots to some people to help combat the surge. U.S. regulators last week authorized a half strength booster shot of Moderna"s vaccine for people aged 65 and older and those who are at risk of severe disease due to health problems or high risk of virus exposure through their jobs. read more Pfizer Inc (PFE.N) and partner BioNTech SE received authorization for boosters for the same groups in September. Bancel said he expects people over age 50 will need annual COVID-19 booster shots starting in 2023 because protection against the virus wanes over time. Some experts say it is unclear if boosters are broadly needed. "I could see a world where from 2023 everyone ages 50 and above is boosting every year," Bancel said. "It"s a population that drives hospitalizations and way too many deaths." Bancel also said Moderna was engaged in a "good ongoing dialogue" about long-term licensing of its COVID-19 vaccine to a South African vaccine manufacturing hub backed by the World Health Organization (WHO). The WHO is working to get more COVID-19 vaccine to Africa to help improve developing countries" access after rich nations bought up most of this year"s supply, leaving many nations with very low vaccination rates. A WHO official in September told Reuters that a lack of progress in talks with Moderna meant the project will take time. "We have been very clear that we will not be litigating (patent rights) during the pandemic," Bancel said. "The question is do they want a license for long term and, as you know, discussing licensing has a lot of implications."