10 Common Questions about AstraZeneca COVID-19 Vaccine

1. What is the Astra-Zeneca vaccine?

It is a vaccine that prevents COVID by using a common cold virus, called an adenovirus, that caries the genetic code for a spike protein on the COVID virus into the cell. The body makes antibodies against this spike protein.

2. How is the vaccine given?

Injection into the muscle, 2 doses 12 weeks apart.

3. What if I get the second dose late?

It will still be effective but should be given as soon as possible after 12 weeks since the first dose does not last that long.

4. Can the vaccine be given at the same time as another vaccine?

The COVID vaccine should be given at least 7 days apart from other vaccines since we do not know enough about the interaction between vaccines.

5. How effective is the Astra-Zeneca vaccine?

There are many studies showing different efficacies but when given 12 weeks apart it is about 60-80% effective against most variants of the COVID vaccine in preventing infection, more than 90% effective in preventing serious infection, and 60-70% effective in preventing spread of the virus to other people.

6. Can I stop wearing a mask after I get the injection?

No, since it is not 100% effective against all strains of the virus.

7. What are the common side effects of the vaccine?

Fever, body aches, headache and nausea are common with the vaccine and may last 2-3 days.

8. If I get the vaccine, will I die from the vaccine?

There is a very rare complication that can occur with the Astra-Zeneca vaccine called thrombosis with thrombocytopenia syndrome (TTS). When this first happened, it was not clear how to treat it and there were deaths. There were 30 cases reported in Australia with 1 or 2 deaths after millions of doses of Astra-Zeneca vaccine being given. Initially, it was not clear how best to treat it but now we know how to identify it and treat it, so it should not be life threatening. The deaths due to this have gone down a lot since it was first recognized. Most of the cases of TTS have been in young women aged less than 50 years. TTS is very rare with just a few cases out of millions. In one study it was 32 cases out of 5 million vaccines. In another it was 18 cases out of one million vaccines. The chance of dying from COVID is much higher than the chance of getting TTS.

9. Do I need to get the vaccine if I have already had COVID?

The answer to that is not so clear but because there are different variants, you may have protection against the variant that made you sick for up to 6 months but not long term. The current answer to this is that you should get the vaccine even though you have had the infection.

10. Who should not get the Astra-Zeneca COVID vaccine?

Those who have a severe allergic reaction to the first dose of the vaccine should not get the second dose of the same kind of vaccine. Those who are on immunosuppressive medicines or are undergoing chemotherapy should check with their doctor before having the COVID vaccine.