COVID-19 outbreaks in pockets around British Columbia have prompted health officials to shorten the recommended delay between vaccinations by three weeks.

Provincial health officer Dr. Bonnie Henry says the change from 49 days to 28 will help bring up the level of community protection in areas of the province that are experiencing outbreaks.

Notices will be sent out to about 170,000 people in the coming days, asking them to book their second dose appointment.

Dr. Henry says the optimal time to wait for the second shot is six to 10 weeks, but that needs to be balanced with the risk of getting COVID-19 during the interval and those who aren't in risky jobs or in a current hot spot may want to wait longer than 28 days.

Dr. Henry says most of the COVID-19 infections now are in the unvaccinated, but when the more infectious Delta variant gets into high-risk settings, such as care homes, it spreads to those who are immunized.

Over 70 per cent of those 12 years and up in the province are fully vaccinated, leaving more than 830,000 who have not had their shots.