That doesn't mean we'll be able to provide safe vaccines for sufficiently novel pathogens, behind Moderna's candidate was a decade and a half of research into making safe vaccines for SARS type coronaviruses, with researchers at the NIH finding one solution in 2017 for the antibody-dependent enhancement issue that had been plaguing such attempts starting with SARS and inactivated whole virus vaccines.
A fast pandemic can also get a long distance before you can ramp up production and vaccinate 8 billion people, with vaccines that so far need freezing for shipping, and medical grade refrigeration afterwords until used. Plus you need to make at least 8 billion syringes and needles and so on.