Thread by @PSampathkumarMD

Vaccine Efficacy updated FAQ:

1) Do vaccines prevent infection? Including delta.

Yes. Unvaccinated 5 times more likely to be infected in LA county study. cdc.gov/mmwr/volumes/7…

2) Do vaccines work as well against delta variant as we hoped?

No. Based on UK studies efficacy is lower against symptomatic infection (see table) but still extremely high against severe disease (>90%).

3) Do vaccines prevent hospitalization and death, including against delta variant.

Yes. Unvaccinated 29 times more likely to be hospitalized due to COVID than vaccinated in LA county study.

4) Why are countries which have high vaccination rates having spike in cases?

Because there are still a number of unvaccinated people even in well vaccinated countries. delta is also vaccine evasive. But deaths this time around are much lower. @FT

5) Do we need to be concerned that vaccine efficacy may be too low in some groups?

Yes. In elderly nursing home residents and immunocompromised. cdc.gov/mmwr/volumes/7… Boosters are recommended.

6) FDA just approved Pfizer. Were the vaccines rushed?

No. Research on the technology used was developed over years. Double blind randomized placebo controlled trials were done and showed high efficacy. We had a huge pandemic so trials enrolled patients very quickly.