LONDON - British scientists on Sunday warned of "pretty miserable winter" ahead for the country due to likely emergence of new respiratory viruses, with further lockdowns a possibility.

Professor Calum Semple, member of the Scientific Advisory Group for Emergencies (SAGE), a British government advisory body, said that children and elderly people will be especially vulnerable to endemic viruses at the end of the year.

Describing it as the "fourth wave winter", he told Times Radio "there's a sting in the tail after every pandemic" because social distancing will have reduced people's exposure to usual endemic respiratory viruses such as pneumonia and bronchiolitis.

"I suspect we'll have a pretty miserable winter because the other respiratory viruses are going to come back and bite us quite hard," he said. "But after that, I think we'll be seeing business as normal next year."

Meanwhile, Susan Hopkins, Public Health England's director for COVID-19, warned "we may have to do further lockdowns this winter" depending on whether hospitals start to become overwhelmed.

"I think we will have alternative ways to manage this, through vaccination, through anti-virals, through drugs, through testing that we didn't have last winter," she told the BBC.

Scientists have warned that a third wave of coronavirus infections is "definitely under way" in England due to the fast spread of the Delta variant first identified in India, even though hospital admissions will hopefully not be on the same scale as in January.

The recent data published by Public Health England showed the AstraZeneca vaccine is 92 percent effective against hospitalization from the Delta variant after two doses, and the Pfizer vaccine is 96 percent effective against hospitalization after two doses.

More than 42.6 million people have been given the first jab of the coronavirus vaccine while more than 31 million people have been fully vaccinated with a second dose, according to the latest official figures.

Experts have warned that coronavirus may continue to evolve for years to come, and eventually it is likely current vaccines will fail to protect against transmission, infection, or even against disease caused by newer variants.

To bring life back to normal, countries such as Britain, China, Russia, the United States as well as the European Union have been racing against time to roll out coronavirus vaccines.