COVID-19 Vaccine Side Effects and Immunity


Day 389: Stay Safe Minnesota

Covid-19 vaccine side effects don’t tell us how well our immune system will protect us from COVID-19, according to report in The Conversation.

According to new study from the Penn Institute of Immunology and published in the Science Immunology, suggests that ‘only a single vaccine dose may be needed to produce a sufficient antibody response‘. The reserchers found that “those who did not have COVID-19—called COVID naïve—did not have a full immune response until after receiving their second vaccine dose, reinforcing the importance of completing the two recommended doses for achieving strong levels of immunity” writes Penn Medicine News. This study provided more insight on the underlying immunobiology of mRNA vaccines.

Previous COVID-19 mRNA vaccine studies on vaccinated individuals have focused on antibodies more than memory B cells. Memory B cells are a strong predictor of future antibody responses, which is why it’s vital to measure B cell responses to these vaccines. This effort to examine memory B cells is important for understanding long-term protection and the ability to respond to variants.

E. John Wherry, PhD, senior author and chair of the department of Systems Pharmacology and Translational Therapeutics and director of the Penn Institute of Immunology in the Perelman School of Medicine at the University of Pennsylvania (source: Penn Medicine News)

According to the Penn Medical News, the team also examined vaccine-induced side effects in relation to immune responses and they found that those who experienced systemic side effects after receiving a vaccine dose—such as fever, chills, headache, and fatigue—had stronger post-vaccination serum antibodies, but not memory B cells.

“Everyone has good responses to the vaccines. They work to protect people against COVID-19. But for those who may be worried about side effects, they are not necessarily a bad thing—they may actually be an indicator of an even better immune response,” Wherry said to the News.

In The Conversation magazine, Robert Finberg, Professor of Medicine at University of Massachusetts Medical School, writes that our body’s initial response to any foreign molecules is called innate immune response and last only hours or days. The second line of more long-stating defense, which takes days to weeks to develop is called adaptive immune response. It relies on your immune system’s T and B cells that learn to recognize particular invaders, such as a protein from the coronavirus.

“It varies from person to person, but how dramatic the initial response is does not necessarily relate to the long-term response. In the case of the two mRNA COVID-19 vaccines, well over 90% of people immunized developed the protective adaptive immune response while fewer than 50% developed any side effects, and most were mild.”

COVID Side Effects

Prof. Finberg writes that side effects from foreign substance injection are normal responses, which include things like fever, muscle pain and discomfort at the injection site, and are mediated by the innate immune response.

“Neutrophils or macrophages in your body notice the vaccine molecules and produce cytokines – molecular signals that cause fever, chills, fatigue and muscle pain. Doctors expect this cytokine reaction to happen any time a foreign substance is injected into the body.”

Prof. Finberg writes “The blood clots that triggered the U.S. to pause distribution of the Johnson & Johnson vaccine are a very rare event, apparently happening with one-in-a-million frequency. Whether they are definitely caused by the vaccine is still under investigation – but if scientists conclude they are, blood clots would be an extremely rare side effect.”

Vaccine Components Causing Side Effects

“The only ‘active ingredientin the Pfizer and Moderna vaccines is the mRNA instructions that tell the recipient’s cells to build a viral protein. But the shots have other components that help the mRNA travel inside your body,” writes Dr. Finberg.

“To get the vaccine’s mRNA into the vaccinated person’s cells where it can do its job, it must evade enzymes in the body that would naturally destroy it. Researchers protected the mRNA in the vaccine by wrapping it in a bubble of lipids that help it avoid destruction. Other ingredients in the shots – like polyethylene glycol, which is part of this lipid envelope – could cause allergic responses.”

Coronavirus-19 vaccination watch

According to the US Centers for Disease Control and Prevention (CDC) COVID vaccination tracker page (as of Apr 20, 9 a.m.) 272,030,795 doses have been distributed and 213,388,238 doses administered. According MDH COVID-19 Response vaccine data (as of April 18) a total of 3,748,622 doses of Covid-19 (Pfizer & Moderna) vaccines have been administered in Minnesota. According to the MDH latest tally (as of Apr 20) the confirmed COVID-19 cases in Minnesota are 558,850 (out of 8,880,741 tested) with 7,031 deaths.