COVID-19 vaccine myths and facts


Keep your guard up against vaccine pseudoscience

Social media has been a double-edged sword during this pandemic. On one hand, it helps with getting up-to-the-minute information, engaging the community in finding solutions to urgent problems, and bringing people together from all over the world in fruitful discourse. On the other, it enables the spread of disinformation, the use of potentially dangerous unproven treatments, and the dissemination of anti-vaxxer propaganda.  

One such harmful post going around asserts that getting vaccinated lowers your immunity to COVID-19 temporarily. This is categorically untrue. However, the post mixes in some real concerns about vaccine breakthrough to draw people in and push its baseless assumptions. This mix of real science and pseudoscience has fooled many smart and educated people. One red flag for any post like this is that it is not attributed to anyone. In this article, we dissect the mostly false facts from the notorious viral post, while affirming which practices can help protect people.

Myth 1: The vaccine starts to form antibodies immediately after entering the body.

This is FALSE. It takes the body about three weeks to form antibodies. When a COVID-19 vaccine is injected, the antigens (substances that elicit an immune response against the virus) are produced in different ways. For mRNA vaccines, the vaccine uses the body’s machinery to produce many copies of the spike protein. This is then recognized by the body as foreign. For inactivated vaccines, the dead pieces of the virus are picked up by scavenger cells called macrophages, which then alert the immune system to produce antibodies and other immune cells. Other vaccines work in similar ways, but the bottom line is that it takes time for the body to recognize antigens, respond, and produce antibodies. From the time of the first dose, it takes approximately three weeks to start producing enough antibodies to begin to have clinically significant protection.

Myth 2: When antibodies are forming in our body, our immunity decreases a lot.

This is FALSE. Every day, we are exposed to different antigens and we are constantly producing antibodies against all sorts of pathogens. Our bodies constantly multitask, and the production of antibodies is a regular task of our immune system. There is no vaccine that decreases someone’s immunity. In fact, after three weeks from the first dose, we already start to see clinically significant protection from disease.  

Myth 3: When we take the second dose of the vaccine after the 21/28 days, our immunity decreases even more.

Completely UNTRUE. Protection from COVID-19 from the first vaccine dose continues and increases with the second dose. Full protection as seen in the clinical trials is attained by the second week after the second dose. Not all vaccines use the 21-day or 28-day time frame, so the post is clearly not considering the different and dynamic scheduling regimens of the different brands.

Myth 4: 14 days after the second dose, when the antibodies are completely formed in our body, our immunity starts to grow rapidly.

This is NOT ACCURATE. It isn’t as if the body, in the second week following the second dose, has a clock that rings and says, “Aha, I’m protected.” It is a spectrum of protection that begins three weeks from the first dose and continues rising past the second dose. The 14-day descriptor is based on clinical trial definitions when they started counting cases for comparison among the vaccinated versus the unvaccinated. In general, we assume complete protection in the second week after the second dose, but this does not mean the vaccine can’t give full protection earlier.

The J&J vaccine is a one dose vaccine and so if the post was accurate that you only get protection two weeks from a second dose, no one would have gotten protection from it. J&J is approved in the US and now has an emergency use listing (EUL) from the World Health Organization (WHO). All the COVID-19 vaccines prevent disease and none of them increase risk of COVID-19. None of the vaccines can give you COVID-19.

Myth 5: During this one and a half month, due to low immunity, the chances of the corona virus entering our body are very high. It is due to an exposure to the virus at this vulnerable time that a person gets infected which makes it very risky to get out of the house during this month and a half.

Absolutely FALSE. Protection from severe COVID-19 already begins after about three weeks from the first dose. Full protection happens two weeks after the second dose but even with one dose, you already have some protection. There is no physiologic basis for increased risk for COVID-19 with any kind of vaccination. Precautions do need to be always taken, however, because there are occasional breakthrough infections, especially before the second dose is given. But the risk of getting COVID-19 is not increased during any time after the vaccination, and the risk progressively goes lower three weeks after the first shot.

FACT (with context): Even after taking two doses of the vaccine, you can become a victim of COVID.

These are called breakthrough infections. These don’t happen often and are usually asymptomatic or mild. Most breakthrough infections occur before the second dose due to partial protection, but even after both doses are given, some people can get COVID-19. The risk of death from a breakthrough infection in a vaccinated person is miniscule compared to natural infection in an unvaccinated patient.

Myth 6: After one and a half months, the immunity in the body rises by 100 to 200 times, after which you are safe.

It isn’t clear what the author means by 100 to 200 times. Perhaps antibody titers? But we still do not know what antibody titers correlate with protection. Aside from antibodies, another arm of the immune system, called cell-mediated immunity, is intimately involved in killing viruses that are inside cells. In general, protection is complete after two weeks from the second dose. For the single dose J&J vaccine this is four weeks from the first dose.

We do need to continue taking precautions even after being fully vaccinated, because our vaccines are not 100% transmission-blocking. Breakthrough infections (usually mild or asymptomatic) can still be passed on to unvaccinated people, but your own risk of dying from COVID-19 is quite small. Once everyone is vaccinated, we can think about getting rid of the masks. Until then, keep your guard up against COVID-19, and against harmful pseudoscience posts.