AARP Eye Center
If you've already received your first dose of a two-dose COVID-19 vaccine, congratulations — you're well on your way to being protected from the coronavirus. But to be fully immunized, it's critical to get that second shot.
Across the country, some people are running into snafus as they try to get their second dose. Winter storms have shut down clinics in some areas, while others have closed because they temporarily ran out of vaccine. There are also scattered reports of scheduling glitches.
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If you've had an appointment canceled, don't wait for someone to call you — be proactive about rescheduling your second shot, advises William Schaffner, M.D., an infectious diseases specialist at Vanderbilt University Medical Center in Nashville, Tennessee, and medical director of the National Foundation for Infectious Diseases.
"We have told everyone these vaccines are 95 percent effective,” he says of the two-dose Moderna and Pfizer-BioNTech vaccines currently in use in the U.S. “But they're only 95 percent effective if you indeed get that second dose."
Here are a few more things to know about the second dose:
1. Your side effects will likely be stronger
Many people who had little to no reaction to the first vaccine dose are reporting that the second one packs a punch — surprising even those who study vaccines for a living.
Greg Poland, M.D., an infectious disease expert at the Mayo Clinic in Rochester, Minnesota, and director of Mayo's vaccine research group, had only mild symptoms after his first dose. But the second one left him shaking — literally — with chills and a temperature of 101.
"I took one Tylenol and went to bed and woke up the next morning 90 percent improved, and by midday I was back to normal,” Poland says. “This is not an indication of something going wrong; it is an indication of a vigorous immune response.”
There is no live virus in the vaccine, so you can't get COVID-19 from being vaccinated.
Participants in clinical trials of both vaccines had experiences similar to Poland's. In Pfizer's clinical trial, for instance, 31 percent of participants ages 18 to 55 reported a fever after the second dose, compared to only 8 percent after the first one. Fatigue, chills, headache and muscle/joint pain were also more common after the second injection for both vaccines.
The good news is, older adults were less likely to experience vaccine reactions, the data shows. Among those age 55 and up in the Pfizer trial, 22 percent experienced fever after the second dose, and 3 percent had a temperature after the first dose.
Schaffner recommends not making any big plans for the day after your scheduled vaccine appointment.