top of page

Covid Vaccine FAQ Part 4: Vaccine Efficacy

Updated: Jul 31, 2021

Picture of Covid virus

This is Part 4 of a 5 part series. Part 1 covers foundational information about how the vaccines work and common questions / myths related to vaccine technology. Part 2 covers questions related to vaccine ingredients and potential toxicity. Part 3 covers questions regarding the safety of the Covid vaccines.

In this section I will cover questions related to vaccine efficacy:

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


How the Vaccine Works Vaccine Ingredients Vaccine Safety Vaccine Necessity


Vaccine Efficacy

These new vaccines appear to be very effective at this point in time. How long will they be effective? We don't know, and will depend in part on how many new variants evolve and what they are like. Before I launch into the Q &A, I do want to take a minute to mention that the media reports on the efficacy of each of the vaccines was based on a type of statistical analysis called "relative risk". There is a different way to assess how effective something is, and that is "actual risk". When looking at "actual risk" the J&J vaccine is actually the most effective (based on the current data, which will change over time). That is not a reason to get J&J over the others, but it is good to remember that there is often more to the story than statistics reported in the media.

So, without further ado, let's jump straight into the FAQ.

Q: How long does the vaccine last? Why should I bother getting the vaccine if it only lasts three months?

A: We don't know how long immunity from the vaccine lasts. We know immunity lasts for one more month after each month has passed. That said, we know at this point that immunity from the vaccines lasts at least 10 months (the earliest date that the first volunteers got the vaccine). Antibodies induced by the vaccines show no signs of fading, so it is likely that they will last for a long time, providing solid immunity to the original virus and the first few variants. Will immunity be permanent like it is with some vaccines? It is possible. Time will tell.

Why should you bother? People are dying and becoming disabled (by the thousands) right now. Also, the more people that get infected, the more chances the virus has to mutate. The faster we can reach herd immunity, the faster we can slow down or stop mutation of the virus, thus reducing the chances that we will end up with a new variant that the vaccines do not work against.

Q: What about break-through infections? Can't you still get Covid after you have been vaccinated?

A: Break through infections are real, as are second infections after having Covid. I have not been able to find solid statistics on second Covid infections after an initial infection, so I don't know if one is more common than the other. In mid April 2021 there were 95 million people vaccinated and 9,245 of those people were hospitalized for Covid after being vaccinated. That is 0.01%. The vaccines were projected to be 90% effective- this indicates that they are closer to 99% effective. So, it is possible to become infected with Covid after getting vaccinated, but it is incredibly rare.

Picture of lady coughing

Q: Isn't having immunity from getting Covid better protection than getting the vaccine?

A: Actually, no. The opposite is true. Immunity from the vaccine is far superior to immunity from infection with Covid.

Early data is finding that the type of immune response we have to Covid infection does not create a strong, lasting antibody response. Infection with Covid seems to activate a part of the immune system that actually blocks the formation of memory cell lines, which greatly lowers long term immunity. These studies found a surprisingly rapid deterioration of immune cell lines needed for immunity following natural infection. This was not universal. Some people do seem to acquire stable immunity (at least several months of immunity) after having Covid, but these studies indicate that it is not a guarantee, and that we should expect natural immunity to fade unusually quickly. Because of the loss of antibodies generated during infection, it is unlikely that we will be able to achieve herd immunity through natural infection. (References 1-4)

Autoimmune risk

Infection with Covid, particularly if the symptoms are severe or it becomes chronic, can increase the risk of developing a new autoimmune disease. These same studies are finding more autoimmunity in people who recover from having severe Covid infections.

The vaccine (especially the mRNA vaccine) appears to produce a strong and lasting antibody response (it does not trigger the part of the immune system that blocks this), and it appears to lower the risk of developing autoimmune disease (certainly compared to infection with Covid). For all of these reasons, the immunity from vaccines is superior to immunity from natural infection. (Reference 2)

Risk of Long Term Covid Syndrome

Post Covid Syndrome is a multi system, chronic inflammatory disorder that develops in around 10% of people who are infected with Covid. Considering the astronomical number of people infected, this has left a huge number of people (36 million or more) suffering from this mysterious, debilitating illness. It can occur even in young people, even following mild or asymptomatic infections. (I have seen several college students with this, after having virtually no symptoms with the initial Covid infection). It can do permanent damage to vital organs such as the heart, lungs, kidneys, and brain. It causes weakness, severe fatigue, severe brain fog, heart arrhythmias, shortness of breath and more. Getting the vaccine gives you immunity without running this risk.

Risk of spreading Covid to others

Hoping to become immune to Covid by getting Covid is, in my opinion, horribly irresponsible. If you got Covid before you had a chance to get vaccinated, I am not blaming you- obviously, this was out of your control. If you choose not to get vaccinated because you are OK with getting Covid yourself, please reconsider. If you contract Covid, you are very likely to spread it to others. Covid has an unusually high incubation time (up to two weeks) compared to other viruses such as the flu (two days). It also stays contagious for up to two weeks after symptoms occur. Additionally, it has an unusually high