Almost all healthy people will develop an antibody response to a COVID-19 vaccine or booster, which offers significant protection against the disease. Research studies are showing that people who develop adverse reactions after they receive a vaccination for COVID-19 have higher protective antibodies against COVID-19. This suggests that having an adverse reaction to the vaccine means that your immune system is responding to help protect you from a future infection. Reactions include fever, chills, muscle pain, nausea, vomiting, headache, fatigue, or injection site pain or rash.
A study of 954 healthcare workers at Johns Hopkins found that those who had fatigue, fever, and chills after two doses of either the Pfizer or Moderna COVID-19 vaccines had a five percent higher anti-spike IgG antibody level (JAMA Intern Med, Aug 2021;181(12):1660-1662). These antibodies specifically help to prevent the COVID virus from entering human cells. Further good news was that almost all people who received the immunizations were protected by these same antibodies. The only exception was one person taking immunosuppressant drugs.
A report on 928 people from the Framingham Heart Study, average age 65, after receiving two doses of either the Pfizer or Moderna COVID vaccine, showed that nearly all subjects made anti-spike antibodies. Those who had reactions to the vaccine had a 50 percent higher antibody response: 48 percent reported systemic symptoms, 12 percent reported local symptoms only, and 40 percent reported no symptoms (JAMA Netw Open, 2022;5(10):e2237908).
A German study found that men, but not women, with more severe adverse reactions to vaccinations had a 150 percent higher median SARS-CoV-2 RBD IgG titer compared to those with no reaction (Vaccines, Sept 27, 2021; 9(10):1089).
Another study found that those who had a severe reaction to the vaccine had slightly higher antibody titers (Vaccines (Basel), Sept 24, 2021;9(10):1063).
A study of South Korean healthcare workers was one exception. The authors found that all people who received the COVID-19 vaccine developed high antibody titers, but the study did not find higher anti-spike IgG antibody levels in those who had reactions to the AstraZeneca or Pfizer vaccines (Korean J Intern Med, 2021;36(6):1486-1491).
My Recommendations
The Moderna and Pfizer vaccines are highly effective in producing anti-spike antibody titers that help to protect you from infection by COVID-19. However, some people who have defective immune systems or are taking immune suppression drugs may not produce adequate protective antibodies. People who develop a reaction to the vaccine produce higher levels of protective antibodies. Reactions include a site rash or sore, swollen arm, fever, chills, muscle pain, nausea, vomiting, headache, or fatigue For most people, protective antibody titers start to drop a month after vaccination, so repeat vaccinations or boosters may be needed.
Dr. Gabe Mirkin is a Villager. Learn more at www.drmirkin.com