COVID-19 vaccines have passed tests and standards by organizations such as the National Academy of Sciences (NAS); The National Institutes for Health (NIH); and the Food and Drug Administration (FDA) which have evaluated the scientific data collected from research on the development and testing of these vaccines to ensure their safety for public distribution.

The fundamental way the safety and efficiency of a vaccine is determined is by conducting clinical trials (studies). In a clinical trial, volunteers are given the actual vaccine. Other volunteers receive a placebo (sodium chloride, salt water). Comparisons are made between the groups and rigorous safety monitoring is conducted to make sure any side effects or safety issues are identified. Once the clinical trials are completed, scientists and regulatory agencies examine the data to determine the safety and efficacy of the vaccine.

The vaccines that are being currently offered have been properly examined before being made available to essential workers and the most vulnerable patients within our society. We have followed development of the vaccines very closely and in fact have recently published an article on “Reopening America: The Road Forward”. Proper procedures have been followed by the vaccine developers, physicians who have tested the vaccines and regulatory agencies who have evaluated the vaccine test results for approval and public usage.

All Americans can be confident that a series of safety measures have been taken to ensure the vaccinations safety and effectiveness. These measures include the following:

  • The FDA established a very clear protocol about the requirements under which it would issue an Emergency Use Authorization (EUA) or full approval for any COVID-19 vaccine intended for public use. The FDA process for approval is well established and documented. The process required peer review by external expert panels not affiliated with the FDA. The FDA leadership publicly reaffirmed in writing their commitment to scientific data driving their discussions and any vaccine approval decisions. Any attempt to circumvent or bypass this certification process would rapidly be brought to public attention and be widely publicized.
  • Nine vaccine manufacturers including Pfizer and BioNTech, Moderna,
  • AstraZeneca, Johnson and Johnson, Merck, GlaxoSmithKline, Novavax, and Sanofi issued a written public pledge that they would complete comprehensive phase 3 clinical trials before seeking FDA approval demonstrating with clear results that their vaccine is safe and effective.
  • Both Pfizer and Moderna when they became aware of public concern and potential mistrust published and made public their clinical trial test protocols.
  • The National Academies of Science provided guidance on conditions required for testing possible public vaccines.
  • The Association for Professionals in Infection Control and Epidemiology (APIC) issued a statement after independent review of study results that the standards for public administration of these vaccines have been met or exceeded.
  • Dr. Anthony Fauci has also stated that all components of the necessary approval process have been met and can be trusted. Dr. Fauci reports that he has personally examined all the data and facts submitted for FDA approval and that the standards required for public safety and effectiveness have been met. Additionally, Dr. Fauci has taken the vaccination himself.


Both Pfizer and Moderna have demonstrated that their vaccines are 95% effective at preventing symptoms of the SARS-CoV2 virus including severe disease.

The FDA and their guidelines had stated that they would likely approve a vaccine that showed at least 50% efficacy. Clinicians and medical experts around the country had hoped for 60% to 75% efficacy. 95% efficacy is extraordinary and represents a clear and remarkable breakthrough which will accelerate the development of American immunity (Herd immunity) across the United States.


Based upon the clinical trials to date, neither the Moderna nor Pfizer vaccine data have reported any serious safety concerns.

Both manufacturers have fully independent safety monitoring boards of medical experts and full safety data has been reviewed by the FDA and expert panels. Historically, most serious side effects become apparent early, usually within 40 days after receiving a vaccine. Intense short- and long-term monitoring of individuals who receive the vaccine will continue to evaluate for safety and possible side effects.


The clinical trials of the Moderna and Pfizer vaccines included under-represented minorities, older age groups and people with various high risk comorbid conditions such as obesity (35.1), diabetes (8.4%), heart and respiratory conditions (7.8%).

Specifically, Pfizer enrolled more than 40,000 people in Phase 2 and Phase 3 clinical trials to evaluate vaccine safety including 81.9% white; 26.2% Latinos; 9.8% African American’s; 4.4 %Asians and 3% other racially diverse patients. By age and sex Pfizer patients included 50.6% male; 49.4% female with 21.4% greater than 65 years of age. 45% of all patients studied were ages 56 to 85.

Moderna enrolled more than 25,000 people of which 37% were racially diverse, 10% black, 20% Hispanic/Latino. 23% of all patients examined and vaccinated were over 65 years old.

Notably, the clinical trials did not include pregnant women or children under the age of 16. Additional trials examining these groups are currently on-going.


The Pfizer and Moderna vaccines use a technology that has not been previously used for a licensed American vaccine. mRNA vaccine technology has been studied for years. This new vaccine technology offers a revolutionary cutting-edge ability to provide vaccination protection in a greatly reduced period of time by stimulating the patient’s own immune system to develop a defense against SARS-CoV2.

Historically, many vaccines injected a weakened or inactivated germ into our bodies e.g. polio, measles, mumps, rubella and chicken pox. This injection triggered our bodies natural immune system to create a response of protection from the germ to which we were vaccinated. However, mRNA vaccines are different. Instead, messenger RNA (mRNA) vaccine teach our bodies natural immune system how to make a specific protein or even just a piece of a protein that triggers an immune response inside our bodies resulting in the production of antibodies which protect us from getting infected when the real virus enters our bodies.

Previously, it took manufacturers years, even decades to develop a vaccine. As with all vaccine development, mRNA-based vaccines are still subject to standard safety trials before they undergo further clinical patient trials (called Phase III trials) to see if they work. These Phase III trials which include safety monitoring and side effect monitoring have been conducted on the Pfizer and Moderna vaccines. To date, there have been no serious side effects reported so far in the two trials of the mNRA based COVID-19 vaccine. Those who receive these vaccines under the Emergency Use Act will be followed very closely for both short and long-term effects.


An Emergency Use Authorization or EUA is a procedure to provide temporary FDA approval of medical products and instruments to make them available as quickly as possible during a public health emergency. The Emergency Use Authorization is not the same as full FDA approval and licensure. However, all of the key safety measures have been taken to ensure that the vaccine is safe and effective. On December 10, 2020 the Pfizer vaccine received emergency use authorization. On December 17, 2020 the Moderna vaccine received emergency use authorization.

Now, the vaccines are being distributed to all states and territories who in turn have developed plans to distribute the vaccine to hospitals and other facilities for use. The CDC has recommended guidelines for the priority of eligibility to receive the vaccination which includes essential frontline workers and at-risk geriatric and vulnerable high risk patients with significant comorbidities.

40 million doses of Pfizer and Moderna vaccine are now being distributed throughout the United States which is enough for 20 million people given the need for two injections for each person.

Given the out-of-control nature of this pandemic with current death rates of 3,000 to 4,000 patients per day as well as the extraordinary impact on individual lives due to State mandated shutdowns; large number of deaths and hospitalizations and growing numbers of people with lingering long term physical health issues even after they recover from acute disease. The risk of vaccination is small compared with the large individual and societal benefits of getting the vaccine. At the current rate of new daily infections, it would still take 3-5 years for America to reach Herd immunity without widespread vaccination.


Getting the vaccine for COVID-19 is voluntary. When you become eligible to receive the vaccine you may have the ability to express a preference for which vaccine you would like to receive. If you are offered a vaccine you did not prefer you will have the choice to either accept the vaccine you were offered or reenter the pool of people waiting for a chance to receive the vaccination.

Please remember that Pfizer and Moderna COVID-19 vaccines require two doses administered 3 weeks apart. Your second dose must be from the same manufacturer as the first dose you received.

Remember vaccines are an important part of controlling the COVID-19 pandemic. Everyone can play a role in assisting the United States population to move through this pandemic and to assist America to get back to our normal life in 2021. While taking the vaccination is not required, this practice highly recommends that you take the vaccination when you become eligible. Currently, both Pfizer and Moderna vaccines require two doses administered 21 days apart and are equally safe.

Vaccine will be given in the muscle of the upper arm. Vaccine does not contain eggs, preservatives or latex.


The side effects are most likely to be experienced after the second dose of either the Moderna or Pfizer vaccine. Common side effects include fever, chills, tiredness and headache. In the vaccine arm, pain, swelling and redness can occur. In clinical trials side effects occurred within seven (7) days of receiving the vaccination were common but usually mild to moderate in intensity and only lasted for a day or two. Additional side effects such as fever, chills, tiredness and headache were more common after receiving the second dose of vaccine and also usually passed within 3-4 days of the second vaccination. Most side effects after each vaccination were mild in most patients. However, a small number of patients have had serious side effects defined as side effects effecting the persons ability to perform daily routines and activities. Additionally, a few people in clinical trials went to the hospital or died after receiving the SARS-CoV2 vaccination. The severe reactions appear to be related to allergic reactions to the vaccine in patients who are known to have previous allergic reactions to vaccines. Notably, vaccinated patients were less likely to have these severe reactions than patients who only received salt water injections. Patients receiving salt water injections in fact had more severe reactions to their injection with salt water than patients who actually received the vaccination. Ongoing studies will help physicians to understand and prevent future cases of these rare severe reactions. If you experience any of these symptoms you should notify your primary care physician immediately. Generally, these symptoms from the vaccination should only be present for a day or two. If symptoms persist you should notify your primary care physician in order to receive medical direction.


Generally, it takes 10 to 14 days for your immune system to respond to a vaccine and provide protection against an infectious disease like SARS-CoV2. Doctors are still learning about how long immunity may last after natural infection with the SARS-CoV2 virus or following COVID-19 vaccination. Following your vaccination, you should continue to practice the recommended infection prevention precautions including wearing a mask, physical distancing, hand hygiene and avoiding large indoor gatherings.


Currently, doctors do not know how long immunity will last after the vaccine is received. For most people with natural immunity after being infected detectable antibody begins to decline after two to four months. However, there is increasing evidence that immunity lasts much longer than initially though with the SARS-CoV2 vaccination. There have been a few rare cases of individuals seemingly being naturally infected twice usually 4-6 months apart. Fortunately, this pattern of reinfection seems to be rare at this time.

The SARS-CoV2 virus does have the ability to mutate e.g. change its ability to infect. However, so far SARS-CoV2 has been genetically stable compared with other respiratory viruses like influenza. The current vaccines will protect against all currently known SARS-CoV2 particles including new mutant identified recently in London England.


The vaccine trials reportedly included people previously infected with the SARS-CoV2 virus. Full evaluation of that data will allow us to know how well the vaccine performed in protecting previously infected people. We do know that there were no serious short-term safety issues reported in patients who had previously been infected and received the SARS-CoV2 vaccination. It is generally thought that natural infection results is better immunity than a vaccine but this is not uniformly the case. For example, tetanus and HPV vaccines are considered better protection that natural immunity. Notably, the vaccine cannot be taken if you are actively infected with COVID-19. Also, it has been recommended that patients who have been infected with SARS-CoV2 virus in the last 4-6 months wait until 6 months in order to receive the vaccination. This will allow others who have not been infected and have not developed immunity to receive the vaccination first. Vaccinating patients recently infected with SARS-CoV2 would utilize doses of vaccine that could be administered to patients who are at high risk and have not yet developed immunity.


Each vaccine is manufactured differently, even those that use similar underlying technology such as Pfizer and Moderna. Once given one type of vaccine, the second dose should be the same type.


Even with a vaccine that is 95% effective, about 1 in 20 people who receive the vaccine will not become immune. It is also unclear if having effective immunity protects you from carrying the virus and passing it on to others.

Until a significant portion of the population becomes immune (70%) either from vaccine or natural infection the precautions must be carefully followed by everyone. Given the enormous task of immunizing a sizable portion of the population to stop spread of the virus, it will take months before we can consider cutting back on these basic safety measures.


All eligible patients should consider obtaining the SARS-CoV2 vaccination particularly elderly patients above the age of 50 with comorbidities including heart disease, lung disease, kidney disease, liver disease, cancer, and obesity. At risk patients either by age or underlying medical conditions are best served by receiving the vaccination as soon as the vaccination is available to them. Consultation with your primary care physician is recommended at all times. If you have additional questions and/or concerns about the vaccination. Additionally, you may call Sollay Medical Center to schedule a consultation to discuss vaccination.

While this newsletter is a great resource the everchanging nature of this virus and how it responds to the vaccine will likely require updates to the information provided by this article. Everyone who has any questions or concerns or just want to clarify something that you have read, heard or seen please speak directly with your own healthcare provider or schedule an appointment to visit Sollay Medical Center.

Terrance L. Baker, MD, MS, FAAEP, FAAFP, FAAGM