Results from clinical trials of the Pfizer-BioNTech and the Moderna COVID-19 vaccines showed about 95 percent effectiveness in preventing COVID-19 infections, and they were given Emergency Use Authorizations (EUA) by the U.S. Food and Drug Administration (FDA) on December 13 and December 20, 2020. The U.S. Centers for Disease Control and Prevention (CDC) says that the clinical trial data “demonstrate that the known and potential benefits of these vaccines outweigh the known and potential harms of becoming infected with the coronavirus disease 2019 (COVID-19). However, we cannot say that the vaccines are safe until we have vaccinated millions and have had longer follow up periods.”

Reported Vaccine Side Effects
So far, minor side effects from the vaccine are common but they last for just a day: fatigue, headaches, chills, fever, muscle or joint pain, and swelling, redness, heat or hardness at the injection site. Now that the vaccine is being widely distributed, data on side effects and complications are being collected and analyzed through CDC’s Vaccine Adverse Event Reporting System (VAERS).

These vaccines contain no virus or parts of the virus. Both contain messenger RNA (mRNA) that was manufactured in the laboratory. The mRNA that is injected into you in the vaccine enters some your cells where the cells’ machinery uses that RNA to make copies of the spike protein of the virus that causes COVID-19. The mRNA itself is destroyed within a few hours after it enters your body. The spike protein of the coronavirus that you made is a foreign protein, so your immune system recognizes that it is different from you. From then on, if the coronavirus enters your body, your immune system does not attack the coronavirus; instead, it attacks and destroys the spike protein of the coronavirus. The spike protein is the key that lets the virus get into your cells. If your immune system destroys the spike protein, the virus cannot get into your cells and disintegrates very quickly.

Everything that you have gotten from the vaccine, including the spike protein copies that your body makes, is gone except the memory of the spike protein for which you are now immune. It looks like this vaccine is safer than all previous vaccines. There is no dead virus. There is no live virus. There is no weakened virus. There is only your immunity against the spike protein.

False Rumors of Side Effects
• There is no evidence to show that mRNA in a vaccine can cause cancer. The mRNA is destroyed soon after it enters your body.
• mRNA does not change your genes. All it does is teach your immune system to recognize and attack the spike protein of the coronavirus if it ever enters your body.
• No fetal tissue is used in the vaccine.
• The vaccines do not cause infertility.
• mRNA cannot cause COVID-19. The vaccine does not contain the virus that causes COVID-19, or any part of the virus.

Who Should Receive a Vaccine?
• People who have diabetes, heart disease, lung disease and similar conditions need to get the vaccine as they are most vulnerable to serious complications from COVID-19.
• People with suppressed immune systems from cancer chemotherapy or immune diseases should be vaccinated.
• At this time, the CDC recommends that those who have had COVID-19 should still get the vaccine.
• After you have been vaccinated, you still should wear a mask and practice all precautions against developing COVID-19 for at least eight weeks. Watch for further guidance from the CDC on this.

CDC Guidance for COVID-19 Vaccination in People with Various Medical Conditions
The CDC has said that “mRNA COVID-19 vaccines (Pfizer and Moderna) may be administered to people with underlying medical conditions provided they have not had a severe allergic reaction to any of the ingredients in the vaccine.”
• We do not have good data on people with immune defects, an overactive immunity, or certain diseases or conditions.
• We have no data yet on the safety of the vaccines for people with HIV, weakened immune systems, or autoimmune conditions such as Guillain-Barre syndrome. People with HIV and weakened immune systems “may receive a COVID-19 vaccine, but they should be aware of the limited safety data . . . People with HIV were included in clinical trials, but safety data specific to this group are not yet available at this time.”
• Bell’s palsy, a temporary facial paralysis, was reported in one person receiving the Pfizer and Moderna vaccines in clinical trials. There is no evidence that the vaccine caused the temporary paralysis of the facial nerve, and at this time the CDC says that, “People who have previously had Bell’s palsy may receive an mRNA COVID-19 vaccine.”

How Rare Side Effects Get Detected
No one in the Pfizer or Moderna trials developed Guillain-Barre syndrome (GBS), a rare disorder in which your own body’s immune system attacks your own nerves. Statistically, one person in 100,000 can be expected to develop Guillain-Barre syndrome, so if a million people are vaccinated, you would expect to see perhaps 10 cases. However, if you have 30 people out of a million who develop Guillain-Barre after vaccination, you may suspect a link to the vaccine. This is why rare side effects may not be identified until after huge numbers of people have received a vaccine. In this example, Guillain-Barre syndrome usually starts as weakness and tingling in your arms or legs and can spread, in extreme cases, to paralyze the whole body. If this happens, the person must be hospitalized immediately, but the vast majority will recover completely.

Severe Allergic Reactions (Anaphylaxis)
Britain has reported several cases of anaphylaxis among people who have received the Pfizer vaccine. In the U.S., 11 cases have been reported since the vaccine rollout began earlier this month, according to the CDC. Most followed receipt of the Pfizer vaccine, but a Boston doctor with a shellfish allergy developed a severe allergic reaction after receiving the Moderna vaccine. If and when other COVID-19 vaccines are authorized for use, health authorities will be watching closely to see whether anaphylaxis may be linked to all COVID-19 vaccines, or only to those such as the Pfizer and Moderna vaccines that are made using mRNA.

A three-year review of adverse reports logged into a U.S. national vaccine database found that anaphylaxis after any type of vaccination is rare, occurring at a rate of about 1.31 per million doses of vaccine administered. Of those cases, 85 percent were in people with a history of allergies. None of the 33 cases — out of 25 million vaccinations in this database — died. Some were given epinephrine, the drug in EpiPens, while others recovered after treatment with antihistamines.

Note: Update from CDC on severe allergic reactions to COVID-19 vaccines (1/12/21):  The CDC now recommends that anyone with a history of immediate allergic reaction of any severity to a previous dose of, or any component of, an mRNA COVID-19 vaccine or to polysorbate should not be vaccinated (MMWR Weekly, January 6, 2021). That means that a person who has developed a severe allergic reactions after a first dose of mRNA COVID-19 vaccine should not receive a second dose. Polysorbate is not an ingredient in the vaccine, but people who are allergic to it can possibly also react to polyethylene glycol in the vaccine. The CDC vaccine fact sheets and many other online sources provide lists of ingredients for each vaccine; check with your doctor if allergies may be a concern for you.

The CDC defined an immediate allergic reaction as: hives, swelling away from the site of the injection, respiratory distress such as wheezing or shortness of breath, or passing out within four hours after the injection. Most allergic reactions occur within 10 to 30 minutes. Non-allergic side effects can include fever, chills or fatigue, and usually occur 1-3 days after vaccination.

A history of allergic reactions not related to vaccines, injectable therapies or components of mRNA vaccines is not a reason to avoid the COVID-19 vaccination. Everyone should be checked for reactions for 30 minutes after the vaccination.

My Recommendations
The COVID-19 vaccines from Pfizer and Moderna contain no virus particles whatever. They contain mRNA that so far appear to be even safer than previous vaccines that contained live, dead or weakened viruses. However, we can make absolute claims of safety only after millions of people have been vaccinated and we have years of follow up. Realize that this pandemic will not end until about 85 percent of the population is immunized, mostly through vaccinations. Getting a vaccine is always a personal decision, but I believe that the risks of having the disease are far greater than the risks of having the vaccine.