How effective is the COVID-19 vaccine?

There are multiple COVID vaccines at various stages of the development, approval and distribution process. The Pfizer vaccine is FDA approved and the Moderna and Johnson & Johnson vaccines are both being administered under Emergency Use Authorization. Clinical trials for the Pfizer and Moderna vaccines showed more than 90% efficacy in preventing symptomatic COVID. That means the rate of catching COVID in vaccinated participants was less than 10% of the rate seen in those who received placebo. There is still a chance of infection post-vaccination. 

The Janssen (Johnson & Johnson) vaccine—authorized for use as a single dose rather than two doses—has been shown in clinical trials including over 40,000 subjects to have a 66% efficacy rate in preventing symptomatic COVID. It has a 93% efficacy rate in preventing hospitalization >14 days after vaccination. No hospitalizations occurred in vaccinated subjects >28 days after vaccination. Seven COVID-related deaths occurred in the placebo group and none in the vaccinated group. This means that those who are vaccinated, if they do get COVID, are extremely unlikely to get a severe enough illness to require hospitalization or become fatal.

As with other vaccines, the more people who get immunized, the greater the community-wide protection against the disease.


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1. How effective is the COVID-19 vaccine?
2. Is the vaccine safe?
3. What are the side effects from the vaccine?
4. What adverse reactions were reported for the vaccine?
5. Will the vaccine give me COVID?
6. How many doses do I need?
7. How do I know if a message or email offering vaccination options is legitimate?
8. When will I get vaccinated?
9. Who should get the vaccine?
10. If I had COVID, should I still get vaccinated?
11. Do I get to choose which vaccine I get?
12. Once I get the vaccine, can I stop wearing a mask?
13. How soon can we get back to pre-pandemic activities?
14. How does the vaccine work?
15. Does the vaccine change my DNA or implant a chip?
16. What is in the vaccine?
17. Where do I find accurate info about the COVID vaccine?
18. Where can I get my COVID-19 Vaccine Record?