Vaccination against COVID-19 has been administered to millions of people worldwide. However, several concerns remain about the vaccinations’ efficacy. One often asked issue is if there is a correlation between adverse reactions to vaccination and future immunity. Are we protected if we have no adverse effects after vaccination?
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Currently, 21 COVID-19 vaccines are approved for usage worldwide. Over 36,500,000 persons in the United Kingdom have been completely vaccinated against COVID-19 to far. Over 162,100,000 persons in the United States are now completely immunized.
According to Google statistics, approximately 13% of the global population has been completely vaccinated against COVID-19.
As stated by the Centers for Disease Control and Prevention (CDC), real-world vaccination safety monitoring continues for all vaccines. Worldwide, health authorities continue to advise recipients of the COVID-19 vaccination to report any adverse reactions to a healthcare practitioner.
Millions of people who have been vaccinated have reported experiencing adverse effects such as swelling, redness, and discomfort at the injection site. Additionally, fever, headache, fatigue, muscular discomfort, chills, and nausea are frequently mentioned.
However, as is the case with any vaccination, not everyone will react similarly. Numerous individuals have reported having no adverse effects after vaccination? Does this indicate they are not immune to SARS-CoV-2?
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‘There is no direct relationship between adverse consequences and protection’
William Schaffner, M.D., professor of infectious diseases at Vanderbilt University Medical Center in Nashville, TN, discussed the link between side effects and immunity to SARS-CoV-2, the virus that causes COVID-19, in an interview with Medical News Today.
He argued that the existence or lack of side effects does not imply immunity. Prof. Schaffner stated, “There is no clear link between side effects and protection.”
Trial data suggest that the two-dose mRNA COVID-19 vaccines developed by Pfizer-BioNTech and Moderna are more than 90% effective. Fewer than 10% of people who are completely vaccinated may have only limited or no protection.
Due to the way vaccinations operate — by stimulating the immune system to develop immunity against the target virus — persons with weakened immune systems may be unable to develop complete or even partial protection against SARS-CoV-2.
Prof. Schaffner notes that some medicines, such as immunosuppressants and some chemotherapy therapies, may potentially impair the efficacy of COVID-19 vaccinations.
What information can we glean from antibody testing?
Antibody testing, some experts have indicated, might aid in determining if a COVID-19 vaccination produced immunity to the novel coronavirus.
However, the Food and Drug Administration (FDA) recently released a statement stating that “antibody testing should not be utilized to determine a person’s degree of immunity or protection against COVID-19 at any time, but especially following a COVID-19 vaccination.”
While antibody testing may appear to be a fair method of determining if an individual has acquired antibodies to SARS-CoV-2, a positive test result does not always mean that an individual will not develop COVID-19.
The FDA is worried that antibody testing may result in a more relaxed attitude toward precautionary measures against infection with the novel coronavirus. This might result in an increase in the spread of SARS-CoV-2.
Dr. Elitza S. Theel, head of the Mayo Clinic’s Infectious Diseases Serology Laboratory in Rochester, Minnesota, responded to MNT’s inquiry concerning antibody testing.
“As with other vaccine-preventable illnesses, there is no proven correlation of immunity for SARS-CoV-2,” Dr. Theel explained.
“And we must bear in mind that the existing COVID-19 serologic assays, which are many and vary in their targets and performance characteristics, were not developed to detect ‘immunity’ to reinfection, but rather to determine if an individual established an immune response to the virus or not. Whether that immune response is adequate to provide long-term immunity is a question that our studies cannot conclusively answer at the moment.”
– Elitza S. Theel, Ph.D.
It generally takes two weeks for the body to develop protection against SARS-CoV-2 following the second dosage of the Pfizer-BioNTech or Moderna vaccines and two weeks following the single dose of the Johnson & Johnson, or Janssen, vaccine. COVID-19 development is still possible throughout this time period.
“The recent spike in [COVID-19] cases,” Dr. Theel said, “is predominantly occurring among unvaccinated persons, which is both disheartening and disappointing because these cases could have been substantially avoided had those individuals chosen to be vaccinated.”