Covid-19 Vaccines are Becoming Available; My Thoughts
Distribution of the Covid-19 vaccine has brought a sense of relief, but also some concerns and perhaps confusion. I have been asked my opinion on the vaccines by a number of our patients. In the following article I offer my perspective.
The concerns are; the speed at which the vaccine was produced, the possibility of side-effects or allergic reactions and the lack of long term follow-up (2 years, 3 years etc.) for test subjects. To address these points, let’s first look at how the vaccine’s work.
What vaccines are available?
There are currently 2 vaccines authorized for use in the United States made by Moderna and Pfizer-BioNTech. Moderna is a Massachusetts based vaccine developer, who partnered with the National Institutes of Health (NIH) to develop and test the coronavirus vaccine labeled mRNA-1273. It has demonstrated an effectiveness rate of 94.1% in preventing Covid-19 illness. Pfizer is an American company that partnered with BioNTech a German company to develop and test the coronavirus vaccine labeled BNT162b2. It has demonstrated an effectiveness rate of 95%.
How do the vaccines work?
The SARS-CoV-2, Covid-19 (coronavirus) is studded with proteins called “spike proteins.” It uses these spike proteins to get inside human cells, where it causes damage and replicates. Both the Moderna and Pfizer-BioNTech vaccines use the virus’s instructions for building the spike protein, but not the virus itself or its replication capacity. These instructions are housed in genetic material called messenger RNA (mRNA). The mRNA contains the genetic instructions for building the spike protein only. It does not alter cellular DNA.
For the mRNA to work, it must enter human cells. In the vaccine, it is wrapped in oily bubbles called lipid nanoparticles to keep it from being destroyed prior to entering the cell. Inside the cells the mRNA is read and production of protein fragments and assembly of the spike proteins begins. The mRNA is eventually destroyed by the cell leaving no permanent trace.
Fully formed spike proteins migrate to the surface of the cell and stick their tips out, resembling the Covid-19 (coronavirus). Additionally, protein fragments are presented on the cell surface.
The cell then dies and the debris from it contain many spike proteins and spike protein fragments, which is engulfed by Antigen Presenting Cells, which present the spike protein fragments on its surface. Once there, the immune system’s “Helper T-Cells” detect them and raise the alarm. This causes proliferation of “B-Cells” which begin production and release of antibodies. These antibodies latch onto the coronavirus spikes, mark the virus for destruction and prevent infection by blocking the spikes from attaching to other cells.
The Antigen Presenting Cells can also activate “Killer T-Cells,” which deploy to seek out and destroy coronavirus infected cells independently.
Why are two doses needed?
Both Moderna and Pfizer-BioNTech’s research showed a better and longer lasting result by providing a second “booster” injection several weeks after the first injection. This has historically been common practice with certain vaccines. The first injection produces a “low affinity” bond for the immunoglobulins to the virus, the second dose upgrades the bonding capacity to a “high affinity” bond. This produces a stronger immune response.
Was the speed at which the vaccine produced, mean it is unsafe?
- Fortunately mRNA research for vaccines had been going on for a decade. So these vaccines are the product of that investment in time.
- Field study enrollments of patients in the trials that usually would have taken 3 years to accomplish, were populated in a matter of months due to the prioritization and billions of dollars of resource allocations.
- The Clinical Research Organization industry’s field trial monitoring systems changed, almost overnight from on-site monitoring to remote monitoring of patients within trials. This meant that Clinical Research Assistants could monitor multiple sites in a day, versus only a few sites in a week when they had to travel to them.
These three points are probably the most significant factors in the accelerated time frame within which the Moderna and Pfizer BioNTech vaccines were developed. Thus far, the vaccines have demonstrated safety and effectiveness. Allergies are discussed below.
Will the Current Vaccine Work on Mutating Strains?
Currently, it is thought that the coronavirus is mutating about every two weeks. Many of the mutations are not viable and simply fade away. Other mutations survive, but do not behave much differently than the original Covid-19 virus. However, mutations such as the “Delta variant,” not only survive, but prove to be more contagious, produce higher viral loads and higher rates of serious illness.
With regard to the vaccines; current indicators are; variants would have to mutate the genes of the entire spike protein to elude the vaccines. This is unlikely and therefore, yes, the current vaccines will work on current mutating strains. The danger is; the longer the virus is viable and finding human hosts, this could lead to it mutating around the vaccines.
If I have allergies, am I more likely to have side-effects?
The following section on allergies is sourced directly from the CDC website.
- If you have had an allergic reaction to other types of vaccines:
If you have had an immediate allergic reaction—even if it was not severe—to a vaccine or injectable therapy for another disease, ask your doctor if you should get a COVID-19 vaccine. Your doctor will help you decide if it is safe for you to get vaccinated.
- If you have allergies not related to vaccines:
CDC recommends that people with a history of severe allergic reactions not related to vaccines or injectable medications—such as food, pet, venom, environmental, or latex allergies—get vaccinated. People with a history of allergies to oral medications or a family history of severe allergic reactions may also get vaccinated.
- If you have had an allergic reaction to polyethylene glycol (PEG) or polysorbate:
These recommendations include allergic reactions to PEG and polysorbate. Polysorbate is not an ingredient in either mRNA COVID-19 vaccine but is closely related to PEG, which is in the vaccines. People who are allergic to PEG or polysorbate should not get an mRNA COVID-19 vaccine.
- You should speak with your primary care doctor if you have any concerns regarding possible allergy contraindications.
What about long term follow-up?
There has not been time to observe long term follow-up. Those of us vaccinated will answer that question with time. However, in the short term, it comes down to weighing risk versus benefit. In the United States we are currently have surpassed 600,000 deaths. Is it riskier to accept the vaccine or to go un-vaccinated, become infected, perhaps seriously ill and perhaps spread the infection to others?
Do masks still have to be worn after getting vaccinated?
The vaccines do not offer “sterilizing immunity,” which would mean those vaccinated can’t contract or pass on the virus. There is a possibility that people who are vaccinated can still become infected, have no symptoms and spread the coronavirus while the immune system is responding. At this point, with the Delta variant spreading quickly, the safest thing we can all do, vaccinated or not is; when possible wear a mask.
Denying the virus its host
Absent the vaccine, the most effective way we have to fight the coronavirus is to deny it a host – which is us. Mask wearing, social distancing and hand washing continue to be our best tools to do just that.
Dr. Shawn Phelan