Vial of vaccine

After getting a COVID-19 vaccine, it’s still important to take safety precautions, such as avoiding close contact with others, to prevent the spread of the virus. Further research is needed to understand the immunity that a COVID-19 vaccine provides and how long protection lasts before experts will consider changing current safety recommendations.

The following recent information is from the Mayo Clinic, Rochester, Minn. It includes frequently asked questions and addresses myths about COVID-19 vaccines.

After I am vaccinated is it OK to visit with loved ones and friends?

After you get both doses of a COVID-19 vaccine, it takes about two weeks for your body to build up protection. But even then you could become infected with the virus that causes COVID-19. Keep in mind that the Pfizer-BioNTech COVID-19 vaccine is 95 percent effective in preventing the COVID-19 virus. The Moderna COVID-19 vaccine is 94.1 percent effective in preventing the COVID-19 virus. While your risk of getting the COVID-19 virus after being vaccinated is low, it is possible.

It’s also not clear if the COVID-19 vaccines reduce the spread of the COVID-19 virus. As a result, it’s not known if a person who is vaccinated could be a carrier of the COVID-19 virus and spread it to others, even if he or she doesn’t become sick. More research is needed to determine if you are still contagious after being vaccinated.

Because of these factors, even once you’re vaccinated you could still pose a health risk to unvaccinated family and friends by visiting with them in person. The risks of serious illness from COVID-19 are highest for people who are older. Nursing home residents are at high risk because they often have multiple underlying health problems, combined with advanced age.

Even after getting the COVID-19 vaccine, continue to follow safety precautions and consider avoiding in-person visits with friends and family until more is known about the immunity the vaccines provide. If you choose to have in-person visits, remember to keep distance between yourself and others (within about 6 feet, or 2 meters). Wear a mask. Visit outdoors, when possible, or open windows and doors to make sure the space is well-ventilated. And wash your hands often.

Can someone who is vaccinated still transmit the COVID-19 virus?

It’s not yet known whether a person who is vaccinated for COVID-19 can get an asymptomatic COVID-19 infection and spread that infection to another person. Those vaccinated for COVID-19 must practice the same safety precautions as those who are not vaccinated for COVID-19, including wearing a mask, practicing social distancing and washing their hands frequently.

What is known is that COVID-19 vaccines are 95 percent effective in preventing symptomatic COVID-19 infection.

Is it safe to use fever-reducing pain medications like acetaminophen before or after receiving the COVID-19 vaccine?

Whether you’re receiving your first or second dose of a COVID-19 vaccine, do not take fever-reducing and pain medications such as Tylenol, Feverall and ibuprofen before being vaccinated just to prevent reactions that haven’t yet happened. Doing so may dampen your immune response. If you do have a moderate headache or body ache as a reaction to being vaccinated for COVID-19, you can take such medications as needed to treat that pain.

Myth: The COVID-19 vaccine is not safe because it was rapidly developed and tested.

Fact: Many pharmaceutical companies invested significant resources into quickly developing a vaccine for COVID-19 because of the worldwide impact of the pandemic. The emergency situation warranted an emergency response but that does not mean that companies bypassed safety protocols or didn’t perform adequate testing.

Mayo Clinic will recommend the use of those vaccines that we are confident are safe. The Pfizer vaccine was created using a novel technology based on the molecular structure of the virus. The novel methodology to develop a COVID-19 vaccine allows it to be free from materials of animal origin and synthesized by an efficient, cell-free process without preservatives. This vaccine developed by Pfizer/BioNTecH has been studied in approximately 43,000 people.

To receive emergency use authorization, which the Pfizer vaccine received, the biopharmaceutical manufacturer must have followed at least half of the study participants for at least two months after completing the vaccination series, and the vaccine must be proven safe and effective in that population. In addition to the safety review by the FDA, the Advisory Committee on Immunization has convened a panel of vaccine safety experts to independently evaluate the safety data from the clinical trial. Mayo Clinic vaccine experts also will review the available data. The safety of COVID-19 vaccine will continue to be closely monitored by the Centers for Disease Control and Prevention and the FDA.

Myth: COVID-19 vaccines cause infertility or miscarriage.

Fact: COVID-19 vaccines have not been linked to infertility or miscarriage.
A sophisticated disinformation campaign has been circulating online, claiming that antibodies to the spike protein of COVID-19 produced from these vaccines will bind to placental proteins and prevent pregnancy. This disinformation is thought to originate from internet postings by a former scientist known to hold anti-vaccine views.

These postings are not scientifically plausible, as COVID-19 infection has not been linked to infertility. Also, no other viral infection or vaccination-inducing immunity by similar mechanisms has been shown to cause infertility. Antibodies to the spike protein have not been linked to infertility after COVID-19 infection. There is no scientific reason to believe this will change after vaccination for COVID-19.

While there are no formal studies, the best evidence comes from women who got sick with COVID-19 while pregnant. While data clearly indicate pregnant women are at higher risk of hospitalization due to COVID-19 infection, there is no evidence of increased miscarriage rates.

During natural infection, the immune system generates the same antibodies to the spike protein that COVID-19 vaccines would. Thus, if COVID-19 affected fertility, there already would be an increase in miscarriage rates in women infected with COVID-19. This has not happened.

Myth: I already had COVID-19 and recovered, so I don’t need to get a COVID-19 vaccine when it’s available.

Fact: There is not enough information currently available to say if or for how long after infection someone is protected from getting COVID-19 again. This is called natural immunity. Early evidence suggests natural immunity from COVID-19 may not last very long, but more studies are needed to better understand this. Mayo Clinic recommends getting the COVID-19 vaccine, even if you’ve had COVID-19 previously. However, those that had COVID-19 should delay vaccination until about 90 days from diagnosis. People should not get vaccinated if in quarantine after exposure or if they have COVID-19 symptoms.

Myth: The COVID-19 vaccine was developed as a way to control the general population either through microchip tracking or nano transducers in our brains.

Fact: There is no vaccine “microchip” and the vaccine will not track people or gather personal information into a database. This myth started after comments made by Bill Gates from The Gates Foundation about a digital certificate of vaccine records. The technology he was referencing is not a microchip, has not been implemented in any manner and is not tied to the development, testing or distribution of the COVID-19 vaccine. 

Myth: The COVID-19 vaccine will alter my DNA.

Fact: The first COVID-19 vaccines to reach the market are  messenger RNA (mRNA) vaccines. According to the CDC, mRNA vaccines work by instructing cells in the body how to make a protein that triggers an immune response. Injecting mRNA into your body will not interact or do anything to the DNA of your cells. Human cells break down and get rid of the mRNA soon after they have finished using the instructions.

Myth: More people will die as a result of a negative side effect to the COVID-19 vaccine than would actually die from the virus.

Fact: Circulating on social media is the claim that COVID-19’s mortality rate is 1 to 2 percent and that people should not be vaccinated against a virus with a high survival rate. However, a 1 percent mortality rate is 10 times more lethal than the seasonal flu. In addition, the mortality rate can vary widely and is influenced by age, sex and underlying health condition.

While some people who receive the vaccine may develop symptoms as their immune system responds, remember that this is common when receiving any vaccine and not considered serious or life-threatening. You cannot get COVID-19 infection from the COVID-19 vaccines; they are inactivated vaccines and not live viruses.

It’s important to recognize that getting the vaccine is not just about survival from COVID-19. It’s about preventing spread of the virus to others and preventing infection that can lead to long-term negative health effects. While no vaccine is 100 percent effective, they are far better than not getting a vaccine. The benefits certainly outweigh the risks in healthy people.

Myth: There are severe side effects of the COVID-19 vaccines.

Fact: There are short-term mild or moderate vaccine reactions that resolve without complication or injury. The early-phase studies of the Pfizer vaccine show that it is safe. About 15 percent of people developed short-lived symptoms at the site of the injection. Fifty percent developed systemic reactions, primarily headache, chills, fatigue or muscle pain or fever lasting for a day or two. Keep in mind that these side effects are indicators that your immune system is responding to the vaccine and are common when receiving vaccines.

Were COVID-19 vaccines developed using fetal tissue?

Neither the Pfizer/BioNTech nor Moderna vaccines for COVID-19 contain fetal cells, and fetal cells were not used in their development or production.

In two animal studies, researchers performed laboratory testing of the vaccines using historically harvested fetal cell lines. However, both animal studies were conducted after these vaccines were already in phase 3 clinical trials.