COVID-19 Vaccine Frequently Asked Questions
Jestin N Carlson MD, Roya Caloia DO, FACEP, FAAEM, John Bedolla MD, Coburn Allen MD, Sameer Ismailjee MD
USACS is committed to the safety of our patients and providers. One of the most effective public health initiatives to help protect one another and ourselves is through vaccinations. There are several COVID-19 vaccines that are being developed and this page has been created to help summarize some important aspects of each.
How do vaccines work?
Vaccines work by causing your body to develop an immune response. Each time your body is exposed to either a vaccine (or virus) it creates antibodies to help fight off the infection and develops immune ‘memory’ to help fight off future infections. This immune response gets stronger each time the body comes in contact with the virus or vaccine, which is why many vaccines require at least two doses.
What types of vaccines are there for COVID-19?
The goal of the COVID-19 vaccines is to introduce some of the viral material into your body so that your body can develop antibodies to help fight the virus in the future and this can be done in several different ways. Most of the COVID-19 vaccines types are just like the ones you received during childhood. This involves injecting either an inactivated or ‘killed’ version of the virus or some of the proteins from COVID-19 inside another virus that our body can defend against referred to as a ‘viral vector’. There are also newer types of vaccines that are being tried for COVID-19 using only parts of the virus such as mRNA or DNA to create an immune response. In these cases, it is not the whole COVID-19 virus, just a small part.
What are the main vaccines that are being considered?
Pfizer (mRNA), Moderna (mRNA) and AstraZenica (viral vector) have all reported results that are promising. Over 50 other vaccines are currently being studied.
What is different about these vaccines and are they safe?
The Pfizer and Moderna vaccines use just a small part of the COVID-19 virus, the mRNA. This technique has been around for decades and has been shown to be safe.
How effective are they?
Vaccines have different efficacy in different groups of people so we cannot say how effective all vaccines are for specific groups, but the early results are encouraging:
- Pfizer ~ 95% effective (tested in a trial of >43,000 participants)
- Moderna ~ 95% effective (tested in a trial of 30,000 participants)
- AstraZenica ~ 70% effective (tested in a trial of >11,000 participants)
For comparison, the annual flu shot is usually 40-50% effective.
What are the downsides of these vaccines?
Minor side effects such as pain at the injection site, headache, fatigue muscle aches and 1-2 days of a fever are common. Serious side effects are very rare (<0.1%).
What if I already had COVID-19? Do I still need to receive the vaccine?
The CDC still recommends that individuals get the vaccine, even if they have previously had COVID-19. While not yet proven, it is believed that the vaccine may help to reduce the chances that you may contract the virus a second time and can potentially reduce the risk of spreading the virus to others.
Are the vaccines safe in specific groups of people (children, pregnant women, people with a weak immune system)?
While there are no trials yet examining the vaccines in these groups, we have information from a number of other vaccines over the past 50 years showing that vaccines are safe in children and during pregnancy. Previous vaccines that only include part of the virus (mRNA and DNA) have been safely given to people with weak immune systems such as those receiving chemotherapy.
Who will get the vaccine and when?
The vaccine is first being administered to front-line healthcare workers such as doctors and nurses. It will then be distributed to individuals such as the elderly and those with pre-existing medical conditions such as diabetes before being available to the general public.
Who should get the vaccine?
Right now, the vaccines are approved for adults (16 years and older for Pfizer; 18 years and older for both Moderna and AstraZeneca). The CDC recommends that almost everyone should get the vaccine including pregnant patients and those with impaired immune systems. Talk to your health care provider about the vaccine if you have more questions.
Can companies track you after you have received the vaccine?
No, they do not have the ability to track you. The FDA asks companies to perform post-market surveillance to ensure the vaccine continue to be safe. This is done with other things that the FDA approves such as when a new medication is approved.