Millions of people across the world have received a COVID-19 vaccine. However, many people are questioning the effectiveness of the vaccines they are receiving. A common question is whether there is a correlation between immunity and side effects following vaccination.

A large proportion of vaccinated individuals have experienced side effects following vaccine administration. These side effects include fever, nausea, tiredness and chills. In addition, many experienced pain, redness and swelling on the arm they received their injection. Side effects vary from person to person but many have also reported no side effects after their vaccine. Could this imply that they are less likely to be protected against the SARS-CoV-2 virus?

William Schaffner, M.D., professor of infectious diseases at Vanderbilt University Medical Center, discussed the relationship between side effects and immunity to SARS-CoV-2. "There is no direct correlation between side effects and protection," said Prof. Schaffner.

However, data from trials of mRNA COVID-19 vaccines, Pfizer-BioNtech and Moderna, indicated that under 10% of fully vaccinated individuals may have limited to no protection against the virus. The trials indicate that the vaccines are over 90% effective. The reason for this is related to the way in which vaccines work- they prompt the body to build up immunity against a target pathogen. Unfortunately, individuals with compromised immune systems may be unable to build up complete immunity to the virus.

Some scientists believe that antibody testing could show whether a COVID-19 vaccine has resulted in immunity to the new coronavirus. The FDA have since released a statement saying that "antibody tests should not be used to evaluate a person's level of immunity or protection from COVID-19 at any time, and especially after the person received a COVID-19 vaccination." Their main concern is that antibody testing could lead to a more relaxed attitude against taking precautions with the coronavirus. This could ultimately result in an increased spread of SARS-CoV-2.

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