Dr. Roach: What makes the COVID vaccine so great?

Keith Roach
To Your Health

Dear Dr. Roach: I had COVID-19 in February 2021. I had no fever, no loss of taste or smell, lasted two days with no persistent symptoms at all! I was cold and tired, and that is all that I experienced.

I am a healthy 66-year-old and take no medication. I have natural God-given immunity, and I do not want to be vaccinated with a COVID-19 vaccine. I do not understand why a vaccinated person can still get COVID-19, still spread COVID-19, still has to wear a mask, still fears getting COVID-19. So, what makes this vaccine so great?

— S.

Dear S.: Neither having received the vaccine nor a history of COVID-19 infection are guarantees that a person will not get COVID-19 again. There are breakthrough infections in people from both categories. What makes the vaccine so great is that you get high-level immunity without the risk of serious illness.

Dr. Keith Roach

I am very glad for you that you did not have any serious complications of the virus. Most people have a pretty benign course, like you did. But hundreds of thousands of people have died, and millions more have long-term complications after COVID-19 infection. The risk of death or long-term complications after vaccination is infinitesimal.

Because you can still get infected and because the infection might have no symptoms at all, it's still recommended for you to wear a mask to protect the people around you. As long as there is ongoing community transmission where you live, wearing a mask gives you additional protection. People with a history of infection have gotten the disease again and died. It is not common, but it can happen.

Scientists are still not sure whether having had the vaccine or having had an infection leads to better and longer-lasting immunity. After having had the infection, getting a vaccine appears to give very, very high protection against recurrent disease, and I would urge you to reconsider getting the vaccine.

Dear Dr. Roach: I have a question I haven't seen addressed. When getting a vaccination, does it matter which arm is used? I almost always get my vaccinations in the left arm but was wondering if I should trade off with my right arm. Could the repeated use of the same muscle result in less effectiveness?

— G.S.

Dear G.S.: It does not matter which arm you use in terms of effectiveness. The arm will usually get sore after the injection. Most people choose their nondominant hand for the vaccine, but some patients prefer using their dominant hand, because the arm movement seems to make the soreness get better faster. When giving multiple vaccines the same day, I usually recommend using both arms.

Some injections seem worse than others; tetanus boosters seem particularly bad, as did the shingles vaccine, both of which were worse, at least for me, than the COVID-19 vaccine.

The purified components of a vaccine are cleared from the arm within a few days, so there is no possibility of reduced effectiveness of a vaccine over time due to the injection being on the same side repeatedly.

Readers may email questions to ToYourGoodHealth@med.cornell.edu.