The Coronavirus Vaccines Explained
Understanding what is true about the novel coronavirus vaccines, and what isn’t, is crucial to business recovery. Anyone who has questions and concerns, should do their research, but myths and fears should not prevent society from looking beyond where we are heading into 2021 – more than 18 million cases and nearly 325,000 deaths in the U.S. alone.
Xenophon’s chief medical expert, Dr. David Hamer, a leading epidemiologist from Boston University’s School of Public Health, offers some truths about the vaccines that should be spread far and wide:
The Coronavirus Vaccines are 95% Effective:
The COVID-19 vaccines from Pfizer/ BioNTech and Moderna provide virtually a 95% effectiveness in preventing people from developing coronavirus symptoms. This data is based on clinical trials that included tens of thousands of people from both companies.
Less Than 0.5% Experience Severe Symptoms
In the same trials vaccines resulted in side effects that were generally mild to moderate and lasted no more than a couple of days. Symptoms included irritation at the injection point of the arm, chills, fatigue, muscles soreness and fevers. Notably though, less than 0.5% of trial participants experienced severe symptoms as an allergic reaction to the vaccines.
There are No Long-Term Side Effects
Thousands of people, whether in trials or with the approved vaccines, have not experienced any long-term side effects. Some have experienced symptoms within minutes of the COVID-19 injection and needed to be treated with epinephrine, but medical providers were able to assist and ensure people with severe allergic reactions were cared for. Otherwise, all side effects have passed within a couple of days for all vaccine recipients.
The Vaccine Does Not Include A Little Bit of the Virus:
Neither the Moderna nor Pfizer vaccine includes the virus that causes COVID-19, SARS-CoV-2. Unlike vaccines for other diseases that include an inactivated or weakened strain of a virus to build an immune response, the COVID-19 vaccine includes mRNA (messenger RNA) that teaches a person’s body to build proteins to combat the virus.
The Vaccine Will Not Give You COVID-19:
Since the vaccines do not contain the virus, it is impossible for someone to develop COVID-19 through the injection. They may develop the side-effects, but they will pass within a couple of days.
The Vaccine Will Not Change Your DNA:
The mRNA vaccine has no impact on a person’s DNA. Messenger RNA allows cells to make proteins that trigger an immune response to the coronavirus, stopping it from entering a person’s cells.
The Coronavirus Vaccines Were Not Rushed Like Many Think:
Development of the vaccines were well underway before the COVID-19 pandemic. How? Since SARS-CoV-2 comes from a family of viruses, including the SARS coronavirus of 2002 and the MERS coronavirus of 2012, scientists had already been developing new vaccines to treat a new virus from the family. In addition, the use of mRNA vaccines to treat diseases had been studied for the past several decades.
The Booster Shot Is Essential:
Without the booster shot, a person’s immune system will not be able to develop a long-term response to the coronavirus. The initial primer shot sets an immune system up to react to the virus initially, developing some memory to it, but it’s the second exposure that establishes long-term effectiveness.
Understanding the data and science behind the vaccines is important for recovery from the impacts of COVID-19 on both our public health and safety, but also on the struggling economy. Believing these truths will help bring life back to “normal” and it will bring business back faster than the alternatives.
About Dr. David Hamer
Chief Medical Officer, Xenophon Strategies

Dr. Davidson Hamer, MD, FACP, FIDSA, FASTMH, FISTM is a Professor of Global Health and Medicine at the Boston University School of Public Health and School of Medicine, and Adjunct Professor of Nutrition at the Tufts University Friedman School of Nutrition Science and Policy.
Dr. Hamer, a board-certified specialist in infectious diseases with a particular interest in tropical infectious diseases, has extensive field experience in neonatal and child survival research including studies of micronutrient interventions, maternal and neonatal health, malaria, pneumonia, and diarrheal diseases.
During the last 20+ years, he has supervised and provided technical support to more than 50 studies in developing countries that evaluated interventions for improving neonatal survival, improving access for pregnant women to emergency obstetrical care, treatment and prevention of malaria, HIV/AIDS, micronutrient deficiencies, diarrheal disease, and pneumonia.
Dr. Hamer received a MD from the University of Vermont College of Medicine and a BA in biology and French from Amherst College. He is a Fellow of the American College of Physicians, Infectious Diseases Society of America, American Society of Tropical Medicine and Hygiene, and the International Society of Travel Medicine.
Dr. Hamer currently has active projects in Bangladesh, Zambia, South Africa, and the United States. Major current projects include neonatal sepsis prevention using prebiotics and probiotics in Bangladesh; using community health workers to improve early childhood development in rural South Africa, antiretroviral adherence among congenitally infected HIV-positive children in Lusaka, Zambia; and a scaled-up evaluation of community-based mothers’ groups for improving early child development in rural Zambia.
In addition, Dr. Hamer is the PI for the GeoSentinel Surveillance Network, a global network of 70 sites in 31 countries that conducts surveillance of emerging infectious diseases using returning travelers, immigrants, and refugees as sentinels of infection (www.istm.org/geosentinel).