The season of giving stretched through most of winter -- as far as flu shots are concerned. The government says up to 17 million Americans voluntarily skipped getting vaccinated, to allow the sick, elderly and health care workers to get shots during an unexpected shortage. As a result, a Centers for Disease Control and Prevention expert says people in the groups most at risk for flu were nearly as protected as they were the year before. The vaccine supply was roughly cut in half when British regulators kept a biotech company from shipping some 48 million doses to the US because of contamination concerns. The CDC says the likely scenario for the next flu season is that about 63 million doses will be available, compared with about 61 million this year.