China is taking action to more closely monitor a swine flu virus that shows the potential to become the next pandemic after COVID-19 based on a study by a team of Chinese researchers.

On Monday, a study by these Chinese researchers published in the peer-reviewed journal, Proceedings of the National Academy of Sciences (PNAS), revealed a high level of concern this swine flu variant called "G4 EA H1N1" might ignite the next global pandemic.

It strongly warned G4 has "all the essential hallmarks of a candidate pandemic virus." G4 is a new virus and is a recombination of the 2009 H1N1 variant and a once prevalent strain found in pigs.

The study emphasized the G4 virus "has shown a sharp increase since 2016, and is the predominant genotype in circulation in pigs detected across at least 10 provinces."

It documented two cases of G4 infections in humans. The virus, however, can't be transmitted from person-to-person at this time, however.

At the core of this problem are pigs. The study called pigs the main "mixing vessels" for G4 EA H1N1 and the next generation of pandemic influenza viruses.

The study urges the Chinese government to conduct "systematic surveillance" of the problem. It also asked the government to monitor pig farms and workers as further transmission might cause the G4 virus to "adapt and become a pandemic."

It warned all the evidence confirms the G4 EA H1N1 virus "is a growing problem in pig farms, and the widespread circulation of G4 viruses in pigs inevitably increases their exposure to humans."

The Chinese research team analyzed almost 30,00 swabs collected from pigs at slaughterhouses in 10 Chinese provinces. The swabs were collected from 2011 to 2018. Researchers found 179 swine influenza viruses. The majority of these were G4.

The study also revealed pig farm workers are showing higher levels of the virus in their blood. As a consequence, close monitoring in human populations, especially among workers in the swine industry, should be urgently implemented.

Zhao Lijian, spokesman for China's Ministry of Foreign Affairs, said China is closely following developments related to the G4 issue. He said China "will take all necessary measures to prevent the spread and outbreak of any virus."

The World Health Organization (WHO) said it will carefully analyze the Chinese study. Spokesman Christian Lindmeier also said it's important to collaborate on findings and keep track of pigs and other animal populations.

He said the Chinese study highlights we cannot let our guard down on influenza. He also said there is a need to remain vigilant and continue surveillance even during the COVID-19 pandemic.