Many countries that have avoided big surges so far don't have access to the vaccines they need to protect their populations. Many of these countries will likely see explosive spread of Covid over the coming weeks and months.
But in places with high rates of vaccination, including much of the United States, the worst is over. Though we'll likely also see big increases in US cases, future waves won't be as deadly. That's because 80% of the most vulnerable Americans -- people over age 65 -- are fully vaccinated.
Vaccines have saved hundreds of thousands of lives already and will save hundreds of thousands more, but they're not 100% effective. No vaccine is. They provide great protection -- not perfect protection.
More cases will lead to more breakthrough infections, which is expected, but vaccines drastically reduce risk of hospitalization and death from Covid. People who are vaccinated are also less likely to spread the virus, so people around them are safer, although they aren't protected completely.