It is hard to believe that 2020 is almost finally over. What a year it has been. The COVID-19 pandemic has affected all of us in a variety of ways, but for many it has put a real damper on 2020. The good news is that the COVID-19 vaccine is finally here and starting to get administered to high-risk and front-line medical personnel this week!
We’ve been getting questions about the COVID-19 vaccine, so I figured I’d let you know a little more about the vaccine, how it works, its efficacy and safety profile, and whether or not we’re planning on getting the vaccine.
To introduce the topic, I think it is best to describe how the vaccine works, and then we can expand our discussion by reviewing some of the common questions and concerns we've been getting asked.
How does the COVID-19 vaccine work?
Our DNA has blueprints to make RNA. That RNA holds the instructions to make proteins. And those proteins carry out the functions for our cells. So, let's focus on the RNA, specifically mRNA (or messenger RNA), which is how this new vaccine works.
COVID-19 (or SARS-CoV-2) has 29 specific protein structures on its surface, but one in particular is called the “spike protein,” which is what it uses to actually infect a healthy cell. Researchers were able to find the specific mRNA that encodes the instructions to make this spike protein. They isolated out this mRNA and packaged it in a lipid nano-particle (basically a small ball of lipids, or fats), making it able to fuse with our cells, enter into our cells, and then use our cellular organs to actually build the spike protein. Once our cells make the spike protein, they place it out on the surface of the cells to show it off to our immune system. This elicits an immune response. Our body tries to destroy this foreign spike protein, but prior to killing it, it makes B cells (antibodies against the spike protein) and T cells (memory cells to be on the lookout for the spike protein again in the future). This way, if we do end up getting exposed to COVID-19 in the future, our immune system can mount a quick and robust response and quickly destroy the virus before we become extremely ill.
Is mRNA technology new?
This concept of mRNA uses to get messages into our cells has been around for 30 years. And we have been using this technology for things like gene therapy (specific cancer treatment) for a long time. But this is the first time a vaccine has been made using this amazing technology.
How did the COVID-19 vaccine get produced so quickly? Is that risky?
Traditionally when a new medication or immunization is being formed, research goes through stages (or PHASES) prior to clinical use.
PHASE 0 is the exploratory study with limited human exposure.
PHASE 1 is when they begin to test the new product on healthy volunteers, focusing primarily on safety, like monitoring for side effects or adverse events and verifying how the agent is metabolized and/or excreted.
PHASE 2 moves into gathering preliminary data on effectiveness, often comparing the new agent to a placebo, while still looking at safety too.
PHASE 3 is when larger numbers of participants are enrolled from different populations and subgroups,, and the new agent is often studied at different doses or in combination with other agents. Once this is completed it can become available for clinical use.
PHASE 4 is after FDA approval for marketing purposes.
This process traditionally would take months to years (often several years). Unfortunately, during a worsening pandemic, several years were not available.
The good news is that this mRNA technology is much faster to produce than previously used traditional immunization production strategies. Instead of having to grow the virus in petri dishes (which is time and labor intensive), all they had to do was make synthetic mRNA that matched the isolated mRNA encoding the spike protein from the COVID-19 virus. In addition, there was tons of funding available, which typically is not done until a vaccine is approved and ready to market, and money makes things go! It was also much faster to gather data because of how prevalent COVID-19 is in our communities and how quickly it has been spreading. And finally, the decision was made to combine some of the PHASEs during the clinical trials to expedite production. And honestly, I think PHASE 2 and 3 could often be done simultaneously in the future without any significant increased risks.
Is the COVID-19 vaccine safe?
There are primarily two companies making a COVID-19 vaccine (there are several others, but only 2 are ready for use), the Pfizer-BioNTech and the Moderna vaccines. Both are similar, using mRNA technology like we discussed. Both have been shown to be very effective, about 90-95% in their studies. And both require two doses given 3-4 weeks apart. The Pfizer vaccine needs to be stored at -94F, while the Moderna vaccine is stable at 36-46F.
Let’s talk about the Pfizer vaccine study, since it has already received EUA (Emergency Use Authorization) from the FDA at the time of writing this article. Note, the Moderna EUA approval is expected in the upcoming days.
In the Pfizer studies there were approximately 44,000 participants. About 22k received the vaccine, and the other 22k received placebo. And, here is what they found:
It was 95% effective at preventing COVID-19 infection
85-90% of participants 16-55 years old (and 60-65% of those 55+) had mild symptoms at the injection site itself (mild pain, mild rash/redness, or mild swelling). This is consistent with the anticipated local immune response, and really isn’t even considered a side effect. Its just the reality of getting poked by a needle and being vaccinated.
40-60% of participants developed mild to moderate symptoms away from the injection site. Primarily this was headache and fatigue.
10-15% developed a low grade fever.
Only 4 serious events were reported. All of these events resolved.
Can pregnant or lactating women get the COVID-19 vaccine?
During the Pfizer study all female participants completed a urine pregnancy test prior to vaccination. 23 pregnancies occurred during the study, either missed by the urine pregnancy test or occurred after vaccination. 12 of those women received the vaccine, the others received placebo. There were no adverse events with any of those 12 pregnancies during the study.
Based on this information, we can assume it is safe to administer to pregnant women or women considering pregnancy. However, 12 cases is a small number. It is worth talking with your physician and OB/GYN about options. Getting COVID-19 during pregnancy and having a febrile illness is very risky for a young fetus, so being vaccinated could very well protect your fetus from unwanted effects if you were to get sick.
Unfortunately there was not enough data gathered on nursing/lactating mothers during the study. However, since this is an mRNA vaccine and not a live virus vaccine, there is not thought to be a risk to a breast feeding infant.
The EUA approval from the FDA allows for pregnant and lactating women to get the vaccine, but discussion with your physician is strongly encouraged.
Can children get the COVID-19 vaccine?
Currently the vaccine only has EUA approval for ages 16 and up. Pfizer did have some children 12-16 years old in their study, but not enough to gather sufficient data. Moderna also has no current data on children. But, both companies are planning to do more research on the 12-16 year old range over the upcoming months. And the American Academy of Pediatrics is pushing for research in those below 12 years old as well, as soon as safely viable.
I think the biggest goal would be to have a vaccine available for children (especially older children) before school restarts in the fall of 2021, but only time will tell if that is a real possibility.
Do kids spread COVID-19 easily?
The initial research seemed to show that children did not contract or spread COVID-19 as easily as adults. However, there has been more recent research pointing the other direction.
One study recently found that children had higher “viral loads” (amounts of virus) in their nose and upper airway than compared to adults. Theoretically, more virus would mean it is easier to spread, however that remains to be seen. And, the viral load did not correlate with severity of symptoms in these children.
There have been a few other small studies that have done contact tracing following COVID-19 positive children who contracted the illness from daycare to follow the spread of illness. Data from these studies shows that about 25% of non-facility contacts ended up contracting COVID-19 from these children, and primarily they were immediate family members, especially their parents/caregive