Covid Vaccine FAQ Part 3: Vaccine Safety

Updated: May 27



This is Part 3 of a multi-part series. Part 1 covers foundational information about how the vaccines work and common questions / myths related to vaccine technology. Part 2 covers questions regarding ingredients and potential toxicity. The information in this current post may be easier to understand after reading Parts 1 and 2 (links below).


In this section I will cover questions related to vaccine safety.


If you would like to navigate directly to the other posts you can click below.

How the Vaccine Works Vaccine Ingredients Vaccine Efficacy Vaccine Necessity


Vaccine Safety


My goal for this section is to help people put the facts into real world perspective. All of the Covid vaccines are extremely safe. At this point they appear to be the cleanest, safest and most effective vaccines ever made. Getting a Covid vaccine is much safer than not getting one. Understanding how safe these vaccines are just requires a bit of perspective as you make your own assessment.


Q: Dr. Becky, did you choose to get the Covid vaccine?

A: You bet your tamales! I was offered the opportunity to get one of the early vaccine appointments in December, 2020 when the first shipments of Moderna and Pfizer vaccines rolled out. I jumped at the opportunity and have been fully vaccinated since mid January. I even considered signing up to be a test subject in March 2020 when they were recruiting test subjects for the Pfizer and Moderna vaccines. In the end, the time commitment they needed was too high, so I was unable to be a test subject, but I trust this technology enough that I certainly would have volunteered without hesitation had my schedule permitted.



Risk of harm from Vaccine vs Risk from Covid


infographic showing risk of getting covid vs risk of vaccine

Based on data available May 2021. (References 1-6). Please note that these numbers, in particular the percent of the population that has gotten Covid, died from Covid or has Post Covid syndrome, will continue to go up as the virus continues to spread.



Q: Are the Covid vaccines safe?

A: Short answer: YES. These vaccines are very, very safe, no matter what scale you use to measure safety. The list of possible adverse events is very short, and the number of each of these adverse events is less than 10 in 1 million. Compared to the risks associated with getting Covid (brain damage, kidney damage, lung damage, or suffocating to death), the risk of death or long term harm from the vaccine are essentially zero (less than 1 in 260 million). When you also factor in the risk of passing the virus on to others and causing this harm to them, or the damage done to our economy and society from the pandemic continuing for another several years, the risk of getting the vaccine is nearly non-existent.


Adverse Events: Allergic reactions

There have been a small handful of allergic reactions (most people had allergic reactions to previous vaccines) among the millions of people who have received the vaccine. This is not unique to the Covid vaccine. Most of the allergic reaction are with the mRNA vaccines. It is speculated that PEG used in the lipid nanoparticle is a likely trigger for those who have been previously sensitized. Right now about 10 people per million will have some level of allergic reaction to these vaccines, about 2 people per million will have an anaphylactic allergic reaction (usually within the first 15 minutes after the vaccine is given). There have been no deaths related to allergic reactions to these vaccines.


Adverse Events: Blood Clots

See Blood Clot question below.


Adverse Events: Flu like symptoms

Some people experience a large immune response to these vaccines. This immune response often manifests as a fever, body aches and headache. The most common pattern is for this to begin about 12 hours after receiving the vaccine, lasting for 24 more hours. In a small percent of people, the immune response to the vaccine (fever, headache, body aches) lasts more than 24 hours. Not everyone has this response.


I would argue that this response is not an adverse event, but an ideal sign that your immune system is doing what it is supposed to do, and that it is doing it robustly. I generally do not recommend that people try to prevent or suppress these symptoms.


While the small number of adverse events are real, Covid is devastating and far more common. Even in people with mild disease, or no symptoms at all, there is a significant risk of developing Post Covid syndrome. Post Covid syndrome is a multi-system inflammatory illness that can damage lungs, kidneys, heart, blood vessels, brain, and more. We do not currently have reliable treatments for this. I have seen several cases of this in my practice, all in young people who had Covid but were virtually asymptomatic during the illness. I can tell you from first hand experience, it is heartbreaking to watch.



Q: Will the vaccine give me blood clots?

A: Probably not, the chances are very, very small. There have not been any clotting events associated with the Pfizer or Moderna mRNA vaccines. The Johnson & Johnson vaccine does carry a very small risk (about 1in 1 million chance) of blood clots in women under 50. The likely variable is estrogen levels and birth control pills (this is not confirmed). It is important to remember that blood clots are not uncommon. Around 100,000 people die from blood clots each year in the US. Covid-19 also dramatically increases blood clot risk, and many deaths of people who were ill with Covid were due to the blood clots that were caused by viral inflammation. So again, getting Covid is much more likely to cause a blood clot than the vaccine.


I do not want to dismiss the gravity of blood clot risk. Blood clots are often devastating. One of these women died, another is in critical condition, several have needed emergency surgery, or other inensive care. This is a scary adverse event. Additionally, these blood clots also occurred in the context of a drop in platelet numbers, so things like baby aspirin will not work for prevention.


Even if all of the blood clots that developed after getting the J&J vaccine were found to be directly caused by the vaccine, there would still only be 28 cases (as of today). Compared to almost 600,000 people dead from Covid. As you can see in the infographic below, you are roughly 500 times more likely to be struck by lightning than you are to get a blood clot from the Covid vaccine (considering all vaccines combined).


My recommendation is to talk to your doctor about your personal risk for blood clots. If you are on birth control pills, hormone replacement (especially estrogen or testosterone), if you have a personal or family history of blood clots or strokes, then that puts you in a higher risk category for developing a blood clot with both Covid infections and the J&J vaccine. If you are in one of these categories, you may want to opt for one of the mRNA vaccines.



Q: What about the adverse events and deaths reported in the VERS database?

A: This is the database that a few conservative politicians and Tucker Carlson have made reference to. The VERS database is open to the public, and is a system of collecting potential concerns about vaccine responses. Anyone can make a report about any symptom or event. This is the data set that is used to start investigating the possible connection between a vaccine and a later adverse health event. Many of the reported events are found not to be connected to vaccines.


To be fair to people who are concerned about reports of vaccine adverse events being suppressed, I think there is wiggle room in this process for that to happen. I do not think it happens all the time, but it seems possible that some real adverse events could be missed during this process. EVEN if all of these cases were wrongly dismissed, and every single one of the adverse events were actually due to the Covid vaccines, we would still be looking at numbers that are VASTLY smaller than the number of people who have gotten Post Covid Syndrome or died from Covid. The vaccines would still be statistically much safer than getting Covid.


To be fair to the CDC and other institutions doing this follow up. They are taking these adverse event reports VERY seriously. This is why they paused the J&J vaccine until they could follow up and confirm the details of each case. They did this knowing that pausing the J&J would increase some people's fear of the vaccine. They paused it anyway because they did not want to miss an issue that might be bigger than they realized. They did due dilligence, and they are continuing to watch the situation closely. The same is true for the AstraZenica vaccine in Europe.



Risk of Death from Covid vaccine vs. other common causes

Info graphic showing risk of death from guns, cars, lightning and covid vaccine

Based on data from 2019. (References 8-11). Please note: it may turn out that deaths from the Covid vaccine have been under reported. Changing that 1 to 30 (representing all known clotting events) would still not change the calculus on this safety number.



Q: These vaccines have been rushed out, I don't want to be experimented on!

A: Getting the vaccine at this point in time does not make you a research subject (any more than you are a research subject when taking any pharmaceutical agent). While these vaccines have been given "emergency clearance" and not full FDA approval, this is actually just a technicality. The vaccines have been proven both safe and effective in very large trials with volunteer subjects. Additionally, while these are the first mRNA vaccines given to the public, mRNA medical technology has been in use for over 30 years and is very well understood. The only thing that had not been done before was inserting this particular mRNA strand into the mix. Likewise viral vector vaccine technology has been in development since the 1990's.

  • The Pfizer study

  • tested its vaccine on 43,998 people, and

  • the initial phase of the study ran from July 2020 to November 2020

  • The Moderna study

  • tested its vaccine on 30,351 people, and

  • the initial phase of the study ran from July 2020 to October 2020

  • The Johnson & Johnson study

  • tested its vaccine on 44,325 people, and

  • the initial phase of the study ran from Sept 2020 to Jan 2021

So, these vaccines were tested on almost 120,000 people before gaining approval.

During these studies they monitored side effects, adverse events, antibody levels and break through infection rates. These studies are now in phase 3 where they are continuing to track the issues above as well as how long antibody levels stay high and rates of break through infection.


Here are some other things to consider:

  1. Our understanding of how the immune system works is more sophisticated than it has ever been.

  2. Vaccine technology is not new. We have over 200 years of accumulated knowledge about how various types of vaccine approaches work.

  3. We had all of the technologies to develop these new vaccines already in place with 20+ years of research and understanding behind them.

  4. We now have the ability to map and understand the genome of almost any organism very rapidly.

  5. We have the ability to share scientific data across the world in an instant and collaborate in ways we have never been able to before.

  6. We now have the ability (with the proper funding, which we now have) to gather and collate huge amounts of data quickly (using systems that have been in use for years).

  7. We have LOTS of data on what has happened with these vaccines so far.

All of this comes together to mean these vaccines were not developed out of the blue, they are not a shot in the dark. We knew exactly what we needed to do and had everything lined up to do it quickly. The vaccines were tested on more than 100K people in the US alone and were found consistently safer and more effective than any vaccine in history.



Q: How can we really know the long-term risks and side effects of these vaccines?

A: This is, I think, is the most important question for many people, and it is a good question. The true anser is that we will not know for sure until years have passed, probably about 10. That said, we can be pretty sure that there are not any mysterious long term risks or side effects from these vaccines now. How can we know that?


Here is my take, and I know that this opinion is shared by most of the top doctors and medical researchers. We have 200 years of experience with vaccines. In those 200 years, we have not seen adverse events from vaccines that occured more than a few weeks after vaccine administration. When adverse events from vaccines happen (they are rare, but they do happen), they happen fairly quickly. There are certainly adverse events that have long term effects, but again, the problems surface soon after the vaccine is given.


With these vaccines, we have 10 months of data based on the 120,000 volunteers who got the vaccines in July 2020. In addition to that we have now given 265 million doses of the vaccine, many of these more than 2 months ago. Now that we have given doses in the millions, we can say with a fair amount of confidence, that we know what the possible adverse events will be. So far they are allergic reactions and blood clots. These are now known entities and can be worked around.

Remember from part 1, that these vaccines all work by tricking our bodies into making the spike protein. Remember also that this only happens for a day or so. Neither the vaccines, nor the spike proteins are present in our bodies for very long. Compare this to infection with Covid, where the virus and the spike protein are in our body for weeks to months. We know infection with Covid can cause long term problems, and those can show up a month or more after the infection. We are not seeing this same pattern with the vaccines.



Q: Is it safe to get the vaccine if I have an autoimmune disease?

A: Yes, for most with autoimmune it is extremely important to get the vaccine. If you are so acutely ill that you are on strong immune suppressants, then please discuss with your doctor the benefits and risks. The main issue with immune suppressant drugs is that you may not get the full benefit of the vaccine.


It is also worth noting that there is a risk of developing new autoimmune disease after being infected with Covid-19. The why is super complicated, but it has to do with the specific parts of the immune system (which cell lines) get activated by the virus. The vaccines protect against this risk. They impart immunity without activating those same cell lines. (See Reference 16 for paper)



Q: Is it safe to get the vaccine if I have chronic inflammation, chronic illness, hypertension or high blood sugar?

A: Definitely, the vaccine is far safer than getting Covid. Risk of severe Covid, and death in these groups is significant. The vaccine lowers or eliminates the risk of severe Covid.

If you are extremely immune compromised (active cancer / chemotherapy, severe autoimmune with immune suppressing drugs, active HIV virus), then discuss the vaccine risks / vs benefits with your specialist.