TAIPEI, Taiwan (AP) ? Chinese state media have stoked concerns about Pfizer?s COVID-19 vaccine, despite rigorous trials indicating it is safe. A government spokesperson has raised the unsubstantiated theory that the coronavirus could have emerged from a U.S. military lab, giving it more credence in China. As the ruling Communist Party faces growing questioning about China's vaccines and renewed criticism of its early COVID-19 response, it is hitting back by encouraging conspiracy theories that some experts say could cause harm. State media and officials are sowing doubts about Western vaccines and the origin of the coronavirus in an apparent bid to deflect the attacks. Both issues are in the spotlight because of the rollout of vaccines globally and the recent arrival of a World Health Organization team in Wuhan, China, to investigate the origins of the virus.