Sunday, Jan 31, 2021
There are a multitude of questions and answers circulating around regarding the COVID-19 vaccine, and it can be difficult to know which sources to trust. Depending on the source, some information is accurate while others provide misinformation or even make false claims. We sat down with Harbin Clinic Infectious Disease physician, Dr. John Hostetler to discuss COVID-19 so that you can equip yourself with reliable information about this infection and the vaccine designed to stop this pandemic. Below is the full video interview where we discuss how the first two vaccines work (Pfizer and Moderna), their safety, and their efficacy. We have updated the blog to include new relevant information.
I’m concerned about how quickly the vaccine was developed. Can you explain how it was made so quickly, and is it safe?
Three critical factors led to the unprecedented speed at which these COVID-19 mRNA (messenger RNA) vaccines were approved for use by the FDA. First, mRNA technology had been in development since the mid-2000’s. There were 12 early phase clinical trials in progress or completed by October 2019 for such things as Ebola, Rabies and influenza. No long term safety concerns emerged from these studies. Second, mRNA vaccines do not utilize live viruses so they can be manufactured quickly in large quantities in a cell-free process that does not involve preservatives or materials of animal origin. Third, and perhaps most important, once the candidate vaccines were shown to be safe and dosing optimized for the best immune response, the U.S. government provided the financial backing to conduct large scale clinical trials with both vaccines in July of 2020. Many volunteers (approximately 70,000) stepped up to participate in the seminal trials proving both long-term safety and efficacy. These studies were at least equal to or exceeded the same FDA standards applied to all other vaccines in common use today. The FDA review process is arguably the most rigorous in the world utilizing many of our nation’s best scientists to independently review the data.
In simple terms, what is a mRNA vaccine, and how is it different from other vaccines?
The purpose of all vaccines is to stimulate an immune response against organisms that would do us harm. This requires exposing our immune system to key proteins that are crucial in producing this response. Scientists already knew from other deadly coronaviruses (SARS, MERS) that the spike proteins on the surface of this virus hold the key to that response. mRNA teaches a few of our cells to make this spike protein without any risk of altering our own DNA (our “genetic code”) or exposing us to a live virus. Once that protein is made, the mRNA along with the other stabilizing components of the vaccine, are cleared from our body leaving us only with a defense system to counter future attacks from this virus.
The Johnson & Johnson vaccine shares with mRNA vaccines the ability to “instruct” certain cells to produce spike proteins on their surfaces to generate an immune response. These instructions are provided as a small segment of DNA contained within a modified cold virus (adenovirus). This virus delivers the DNA to our cells but it is incapable of reproducing itself in our body and it cannot alter our own DNA. This DNA produces mRNA to then instruct our cells to produce spike proteins as with the Moderna and Pfizer vaccines. All the components of the vaccine including the adenovirus, the DNA and mRNA segments are immediately broken down after the spike protein is produced with no lasting components. This method has been in wide use for an Ebola vaccine in Africa and has proven to be quite safe and effective. The AstraZeneca vaccine works in a similar manner with a different adenovirus. Only the Johnson & Johnson vaccine is approved for a single dose but a 2 dose regimen is being actively studied. Two doses may be needed to achieve the same responses as the mRNA vaccines.
What are some of the adverse reactions someone might experience after getting the vaccine? Is it more dangerous than getting COVID-19?
Many individuals will experience mild to moderate side effects in the first few hours up to about 2 days after the vaccine such as sore arm, fatigue, muscle aches, headaches, sometimes nausea and even fever in about 15% of cases. These can be taken as sign of a strong immune response to the vaccine and should not be worrisome that there will be long-term effects. Per the CDC, rarely, persons who received the Pfizer vaccine experienced what is termed anaphylaxis at a rate of approximately 1/100,000. Such individuals experienced symptoms typically within 15 to 30 minutes including hives, swollen tongue or lips, or wheezing. Experience so far is that these symptoms can be quickly mitigated with medication by trained medical providers. No such data has been published yet regarding the Moderna vaccine though it is expected to be similar. It may be wise to schedule your vaccine prior to expected time off such as a Friday when not working the weekend.
Are there any people who should not take the vaccine at this time?
The only clear reason that an individual shouldn’t receive the two mRNA vaccines is if they have a known allergic reaction to any of their components. Both vaccines include the mRNA itself and a small “fat” molecule called a “lipid nanoparticle”, both of which are proprietary but very similar in each of the two mRNA vaccines. There is also a compound called “polypropylene glycol,” which is the same as the common laxative but not previously used on a large scale as part of a vaccine. Pregnancy and weakened immune systems are not considered groups in which the vaccine should be withheld, but separate trials are underway to establish use in these areas. It is important here to remember that no live virus is present in these vaccines, and there is a consensus of opinion among scientists that these vaccines are safe for use in these populations. More information for these individuals can be found on the CDC website. Specific to pregnant patients or those wishing to become pregnant in the near future, the American College of Obstetricians and Gynecologists (ACOG) and the Society for Maternal-Fetal Medicine (SMFM) recommend that women who are pregnant, breastfeeding or planning to become pregnant receive the vaccine. They note that the risk of complications and hospitalization are significantly higher for pregnant women who contract COVID-19.
Once you receive the vaccine, can you still infect others?
After receiving both dose of mRNA-based COVID-19 vaccine, there is a 95% efficacy against symptomatic infection. An unanswered question remains as to whether vaccinated persons could develop an asymptomatic infection. This is considered unlikely, but until that question is answered, it is important to realize that asymptomatic infections account for a large proportion of viral transmissions. . The CDC has provided updated guidelines for fully vaccinated individuals here.
If you’ve already had COVID-19 and recovered, should you still get the vaccine?
According to the most recent reports, COVID-19 infection results in immunity for at least 6 months and potentially longer in the vast majority of persons. Rare re-infections have been reported at rates considered <1%. There is reason to believe, however, that immunity from the vaccine may result in more durable protection because, at least in part, antibody levels achieved with vaccination are more consistent and often of greater magnitude vs. natural infection.
For the most accurate and updated information regarding the COVID-19 vaccine, visit the Centers for Disease Control and Prevention (CDC) website here.