President Duterte urged the public to pray that the existing coronavirus disease (COVID-19) variants will not get worse in fear that even a vaccine may not work on them anymore.

Duterte made the statement days after the Philippines received 15,000 doses of the Russian-made Sputnik V COVID-19 vaccine on Saturday.

In his pre-recorded public address on Monday evening, President Duterte expressed confidence that the Philippines will not have a problem when it comes to getting vaccines.

"Wala tayong problema sa tingin ko sa acquisition of bakuna (We have no problem with the acquisition of vaccines) because we have guarantees from countries who honor the contract," he said.

The President, however, feared that vaccines may become useless if the existing COVID-19 variants will get worse.

"Let us just pray na itong mga variants, itong mga mutants (that these variants, these mutants), will not go haywire," he said.

"'Yan ang bantayin natin baka 'di na ma-control ng isang bakuna lang and we do not have insight yet kung anong pinag-aralan ng scientists (That is what we should watch out for because a single vaccine may not be enough to control it. We do not have insight yet about the variants that scientists are studying)," he added.

Meanwhile, President Duterte vowed to provide Filipino scientists the things they need as they do their work.

"This will be a challenge to our native scientists to work harder. Kaya naman nila kung talagang trabahuin nila (They can do it if they will just really work hard on it)," he said.

"We will provide them all that is necessary to make a conclusive finding-- if they have one," he added.

The country started its vaccination program against COVID-19 on March 1. President Duterte got vaccinated on May 3 with the Chinese-made Sinopharm vaccine which is yet to get an emergency use authorization (EUA) from the Food and Drug Administration (FDA).