The Labour Party leader said that he was concerned about the shortage of monkeypox vaccine doses in Brighton.
Sir Keir Starmer said that the government should get a grip in an interview on BBC Sussex.
Brighton and Hove has the highest number of monkeypox cases outside London but vaccine stocks ran out last week.
According to the UK Health Security Agency, there have been 69 cases of monkeypox in Brighton and Hove to date.
The BBC quoted the government as saying that people in Brighton who already had an appointment could still have their jab despite the supply problems.
The latest UK Health Security Agency figures show there have been 69 cases of monkeypox in Brighton to date, the highest number of cases outside of London.
Sir Keir told the BBC radio station: “I completely understand why a number of people are very frustrated and angry by this. Some can’t get their first vaccine. Some can’t get their second.
“It’s the same old story with this government which is seeing a problem on the horizon, failing to plan, putting their head in the sand and then inflicting misery on people when they needn’t have done so.”
The Department of Health and Social Care said that a further 100,000 doses of the vaccine were due to reach Britain by October.
And the BBC said that remaining stocks of the jab would be allocated to local sexual health services “in the coming days”.
But Brighton is not expected to receive further vaccine doses until the end of next month.
According to the government: “The 50,000 or so vaccines administered by the NHS to date, to those among the highest risk of exposure, should have a significant impact on the transmission of the virus.”