SARS-CoV-2 Vaccines
Source: FAA Safety Briefing May/June 2021
By: Leo M. Hattrup, M.D., FAA Medical Officer
At the beginning of 2020, many viewed COVID-19 as a distant problem. Our world is now very different and how long the “new normal” will last is unknown. However, we have made considerable scientific progress this past year. Medical authorities quickly realized that we needed to develop and approve a vaccine quicker than usual to prevent spread and to minimize transmission.
Vaccines are created in various ways. Live, but attenuated, infectious vaccines such as measles or chickenpox are very effective, with low risk of actually causing the disease. Inactivated/killed agent vaccines are slightly less effective, but do not risk the disease. Many influenza vaccines utilize this approach. Vaccines such as tetanus and diphtheria introduce the inactivated toxin. These prevent the adverse effect. The COVID-19 vaccines include a subunit of a protein found on the surface of the virus. This protein cannot cause an infection from the virus, but will help our body build an immunity against the virus.
When necessary for public health, the Food and Drug Administration (FDA) has the authority to make emergency use authorization (EUA) decisions on vaccine effectiveness and safety prior to obtaining all the normally required data. The FDA closely monitors available data and updates authorizations when necessary. After FDA approval, the CDC gives clinical and general recommendations. These usually start conservative and liberalize as the CDC analyzes additional data that confirm safety and efficacy.
In just one year, over 200 COVID-19 vaccines are in development around the world. At this writing, at least 10 are currently in use worldwide with three available in the U.S. Since granting the first EUA in December 2020, the FDA approved use of two additional COVID-19 vaccines. Over 75 million doses have been administered (as of March 1, 2021) in this country alone. By the time you read this, the expectation is for double that number, which is truly remarkable.
In general, the FAA does not review a new medication or treatment until one year after full FDA approval. This allows sufficient time for uncommon, but significant, adverse effects to manifest. After careful review of the available data regarding safety profiles, the FAA Office of Aerospace Medicine (AAM) determined it could safely shorten this observation period for the EUA-approved COVID vaccines. Thus far, the clinical data show that both the Pfizer and Moderna vaccines are safe and effective. The immune system begins to make antibodies after one dose of any of the vaccines. Risk of serious illness and hospitalization is negligible and the vaccines have been 95% effective against death from COVID-19. From the Pfizer or Moderna vaccine, the CDC notes that about 70% report a sore arm at the injection site. Over 20% report fatigue after the first dose and almost 50% do after the second dose. Other common side effects include headache, fever, muscle aches, and chills. Data has shown that side effects start approximately 1-2 days after vaccination and last for about 1-2 days after the symptoms first begin.
The FDA recently granted EUA to the vaccine developed by Johnson & Johnson (Janssen). This vaccine uses a different method, but remains non-infectious and has the advantage of requiring only a single dose. The FAA allows airmen to use the Pfizer, Moderna, and J&J/Janssen EUA COVID vaccines, but mandates a minimum 48-hour grounding after any of these (note: 14 CFR section 61.53 still applies). The FAA will continue to monitor patient response to each vaccine and may adjust this policy as necessary to ensure aviation safety. We will evaluate additional vaccines when an EUA is issued.
With over 100 million cases worldwide, it is not surprising that there are multiple new SARS-CoV-2 variants. Fortunately, the vaccines in use appear to significantly reduce the likelihood of hospitalization and death and reduce community transmission from these variants. Also, simply reducing disease prevalence will decrease the number of additional new variants. The scientific community and industry are evaluating the need for modification of the current vaccines and/or a booster, similar to what is already done for the influenza vaccines annually. Meanwhile, wear a mask, practice social distancing, get vaccinated, and fly safe.
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