People receive the Sinovac COVID-19 vaccine as the Thai resort island of Phuket rushes to vaccinate its population amid the coronavirus disease (COVID-19) outbreak, and ahead of a July 1 ending of strict quarantine for overseas visitors, to bring back tourism revenue in Phuket, Thailand, April 1, 2021. In Thailand, it's the all-important tourism sector that has jumped to the head of the COVID-19 vaccination line. REUTERS/Jorge Silva

People receive the Sinovac COVID-19 vaccine as the Thai resort island of Phuket rushes to vaccinate its population amid the coronavirus disease (COVID-19) outbreak, and ahead of a July 1 ending of strict quarantine for overseas visitors, to bring back tourism revenue in Phuket, Thailand, April 1, 2021. The island of Phuket aims to deliver shots to at least 460,000 people - most of its population - as it gears up for July 1, when vaccinated overseas visitors will no longer be required to quarantine. REUTERS/Jorge Silva

People receive the Sinovac COVID-19 vaccine as the Thai resort island of Phuket rushes to vaccinate its population amid the coronavirus disease (COVID-19) outbreak, and ahead of a July 1 ending of strict quarantine for overseas visitors, to bring back tourism revenue in Phuket, Thailand, April 1, 2021. Phuket also has its own international airport and tourists would be able to roam the island freely without posing any coronavirus risk to the rest of Thailand's population. REUTERS/Jorge Silva

People receive the Sinovac COVID-19 vaccine as the Thai resort island of Phuket rushes to vaccinate its population amid the coronavirus disease (COVID-19) outbreak, and ahead of a July 1 ending of strict quarantine for overseas visitors, to bring back tourism revenue in Phuket, Thailand, April 1, 2021. REUTERS/Jorge Silva

A woman reacts after receiving the Sinovac COVID-19 vaccine as the Thai resort island of Phuket rushes to vaccinate its population amid the coronavirus disease (COVID-19) outbreak, and ahead of a July 1 ending of strict quarantine for overseas visitors, to bring back tourism revenue in Phuket, Thailand, April 1, 2021. REUTERS/Jorge Silva

People receive the Sinovac COVID-19 vaccine as the Thai resort island of Phuket rushes to vaccinate its population amid the coronavirus disease (COVID-19) outbreak, and ahead of a July 1 ending of strict quarantine for overseas visitors, to bring back tourism revenue in Phuket, Thailand, April 1, 2021. REUTERS/Jorge Silva