People who had side effects and reactions to the first dose of the COVID-19 vaccine may have had some level of the new coronavirus in their system before receiving the injection, Yahoo! Life reports.
What’s going on?
Health experts acknowledged that people who get their second shot of the COVID-19 vaccine tend to experience some side effects for a day or two. But there is also a group that has symptoms after the first dose.
Dr. Erin Morcomb, a physician with the Wisconsin Mayo Clinic Health System, told Yahoo! The life that people who received their first dose experienced symptoms because they already had COVID-19 in their system.
- “What we’ve seen in studies is that the second dose tends to have a little more potential to cause side effects than the first dose, but for people who have had a COVID-19 infection before and then recovered, they are at higher risk levels of having those same side effects after the first dose, “he told Yahoo! Lifetime.
People who previously contracted COVID-19 have an immune system ready to fight it. So the first shot acts as a second shot for someone who did not contract COVID-19.
- “Having had their active COVID-19 infection, they themselves have produced some antibodies in their body against the national infection,” Morcomb says. “Then when they get their first dose, their body is already recognizing that they have some antibodies and they can generate a really robust immune response to that first dose of vaccine.”
Why the first dose is effective
This also adds to the body of evidence that one dose might be sufficient for those who had COVID-19, at least initially. As I wrote for Deseret News, there is research saying that the first dose of the Pfizer COVID-19 vaccine, which has two injections, can create high efficacy in the fight against the novel coronavirus. In fact, the first dose of the Pfizer COVID-19 vaccine has been found to be 85% effective against COVID-19 symptoms after 15 to 28 days, The Wall Street Journal reports.
That same study found that it is also 75% effective in stopping asymptomatic COVID-19 cases, according to The Hill.
That said, experts still recommend that people receive both doses of the COVID-19 vaccine (or a Johnson & Johnson injection) for complete protection against the coronavirus.