timothy albertson says the same side effects are showing up again. >> sore arms and low grade fevers. the power of the two dose vaccine declines slightly every two months. so how long will it remain in the immune system. >> extremely lucky. not vaccinated for fear that they will be >> officials tell nbc news they will start to give booster shots of a pfizer vaccine to people over 60. dr. albertson believe that's -- believes that could be in our future. we're probably getting a yearly vaccination the cdc says it doesn't recommend a covid booster shot at this time. nbc bay area knew. >> san francisco is eyeing a possible mask mandate. >> we see the delta variant really taking flight right now. at least 77% of san francisco residents are fully vaccinated. that's incredible and we school masks will be vital in protecting children particularly those under the age of 12 that are not yet eligible. they will outline a policy some time next week. >> let's go to tokyo and show you the olympic flame. early friday morning now in tokyo as we continue our olympic coverage. now all eyes remain in gy