Dovish Federal Reserve minutes released on Wednesday, which reiterated that the U.S. central bank was in no rush to raise interest rates, also weighed on Treasury yields.
Brent futures rose 20 cents, or 0.3pc, to $63.36 a barrel by 11:43 a.m. EDT (1543 GMT), while U.S. West Texas Intermediate (WTI) crude rose 2 cents to $59.79.
Cases of the virus have been increasing for several weeks in Spain, which has fully vaccinated some 3.02 million people and administered a total of 9.8 million shots.
Over the past 24 hours, the country officially recorded 22,586 new cases of infection, reaching a new high, health ministry spokeswoman Sima Sadat Lari said.
India's vast vaccination programme is reportedly experiencing problems having administered 87 million shots so far in a population of 1.3 billion people.
Hancock emphasised the serious side effects were "extremely rare", adding that all three of the vaccines so far approved for use in Britain were "safe for all ages".
"The current rate of infection in Pakistan is also reportedly lower than the UK," the letter said.
We would be grateful if the full data and evidence can be provided to show why these specific countries have been added to the red list and provide an urgent clarification of the decision-making process, the MPs asked.