Standing on the shore of Manila Bay, Melvin Chua, 25, folded a letter of thanks carefully into a bottle and let it flow into the sea.

"Dear Chinese vaccine, I would like to thank you for providing supplies to my country, the Philippines, to save the Philippine people and their families," Chua's letter reads.

China was the first-ever country to donate and supply the Philippines with COVID-19 vaccines.

Chua knows every narrow street of an urban district called Pembo in the Philippines' capital city Manila like the back of his hand.

Rain or shine, Chua sold dish sponges to support his family and fund his education. Hawking dish sponges for 13 years earned him the nickname "sponge boy."

Chua was among the Filipinos who earned a scholarship to pursue a master's degree in international business administration at Renmin University of China in Beijing in 2019. However, it was not long after he arrived in Beijing that the COVID-19 pandemic broke out.

"At the time, I was terrified. Unfortunately, I did not have enough money to return home. But looking back now, I'm really proud of my decision to stay in China during the difficult time," Chua said.

Chua noted that he had been fully vaccinated in his university in May this year, whereas the Philippines was still short of COVID-19 vaccines, and his family and friends could not get their jabs.

"I was really happy and grateful to be able to get vaccinated in Beijing, because it just gave me so much confidence to explore (the city and my university). I was even able to celebrate festivals and birthdays with my friends and visit some beautiful places in Beijing," he said.

Moreover, with the continuous and timely delivery of life-saving vaccines from China, nearly 38 million Philippine people have been fully vaccinated, including Chua's mother and siblings.

China has sustained its COVID-19 vaccine supply to the Philippines since the first delivery on Feb. 28, allowing the country to kick off its vaccination drive on March 1. To date, the Philippines has received more than 158.5 million doses of COVID-19 vaccines from different vaccine makers, with China being its biggest vaccine supplier.

"We could not feel more safe and protected. I trust that you will continue to supply the world to save lives and bring the world to its normal state again," Chua's letter reads.

According to Chua, after having experienced so many "first times" of seeing snow, tasting Chinese hotpot, meeting Chinese and foreign friends from all over the world, he would like to use "life-changing" and "magical" as keywords to describe his adventure in Beijing.

Chua just went back to his home country in December after finishing his education in Beijing. He is looking forward to working in a technology or internet company soon, fully utilizing his social network established during his stay in China to help the Philippine communities become better.

"I've experienced a lot of incredible things in Beijing, especially the vibrant community. I plan to bring that community to the Philippines and encourage many young people to talk about big things such as entrepreneurship, technology, and AI. I want them to feel or receive the same environment that I had in Beijing."