For two-dose vaccines, the interval between doses depends on which vaccine you get and the guidelines from the government in your country.

For the Oxford-AstraZeneca vaccines, longer intervals between doses between eight to twelve weeks give greater protection. For the Pfizer-BionTech, Moderna and Sinopharm vaccines, you should ideally get your second dose between three to four weeks after your first dose.

Even a single dose of a two-dose vaccine should provide some protection from the virus, so if you get the chance please get the vaccine.