When pediatrician Eric Ball opened a refrigerator full of childhood vaccines, all the expected shots were there — DTaP, polio, pneumococcal vaccine — except one. “This is where we usually store our covid vaccines, but we don’t have any right now because they all expired at the end of last year and we had to dispose of them,” said Ball, who is part of a pediatric practice in Orange County, California. “We thought demand would be way higher than it was.” Pediatricians across the country are pre-ordering the updated and reformulated covid-19 vaccine for the fall and winter respiratory virus seaso…