Filipinos' optimism on the arrival of the vaccines against coronavirus disease could have contributed in the surge of infections in the country, the World Health Organization said on Monday.

In the "Laging Handa" public briefing, Rabindra Abeyasinghe, WHO representative to the Philippines, said this was also the case in other countries which rolled out COVID-19 vaccines.

"It's not vaccine confidence but vaccine optimism (that is) responsible to some extent, not only in the Philippines," he said when asked of the possible reason for the sudden rise in COVID-19 infections in the Philippines.

He said with the arrival of the vaccines, people seemed to start relaxing and to go out more frequently because of the long quarantine period.

"These little changes believed to have caused for the virus to transmit more freely," Abeyasinghe said.

The government started to rollout its COVID-19 vaccination program on March 1 with the arrival of China's Sinovac vaccine. The Department of Health is also using AstraZeneca vaccine, which was donated through the World Health Organization-led COVAX facility.

Abeyasinghe said the increase in COVID-19 cases "could also be to some extent link to circulation of new variants."

"This mix of factors has been causing high level of transmission in the Philippines also," he said.

As of March 21, the Philippines logged 7,757 new COVID-19 cases, bringing the total cases to 663,794, including 577,754 recoveries and 12,968 deaths. Celerina Monte/DMS