Vaccines to prevent COVID-19 are proving to be the best hope for ending the pandemic. As the U.S. Food and Drug Administration (FDA) continues authorizing emergency use of COVID-19 vaccines, many people have questions. Below are commonly-asked questions, with answers provided/reviewed by Dr. Majed Koleilat, Deaconess Clinic Allergist & Immunologist, and Deaconess clinical pharmacists.
1. What is an mRNA vaccine?
mRNA stands for messenger ribonucleic acid. mRNA is a genetic sequence that provides the blueprint for something to be developed in a cell (generally a protein).
The new COVID-19 mRNA vaccine contains a small piece of genetic material created in a lab. This mRNA creates a blueprint for a small part of the SARS-2-Coronavirus called the “spike protein.” This is the part of virus that causes the immune system to recognize that it needs to make antibodies toward this virus.
The mRNA vaccine CANNOT cause an actual infection, as the only part of the blueprint is for the spike protein, and not for the actual virus itself.
2. Can the vaccine alter your DNA?
The mRNA from the vaccine does not enter the nucleus of the cell (where your DNA is stored), so it cannot change your DNA.
3. How long does the mRNA stick around in the cell?
mRNA is quickly read by ribosomes (proteins in the cell) and translated into the spike protein that leads the body to develop antibodies.It is broken down immediately after the cell makes the spike protein.
In fact, mRNA breaks down very quickly in general and is not stable for long at normal temperatures, which is why there are such strict storage requirements for some of these vaccines. For example, the vaccine from Pfizer must be stored at -70°C to be stable longer- term. Once refrigerated, it is only good for 5 days, and at room temperature for only about 12 hours.
4. Can the vaccine make me sick with COVID-19?
No. None of the currently authorized vaccines contain the virus that causes COVID-19. This means that a COVID-19 vaccine cannot make you sick with COVID-19.
However, people can be exposed to the coronavirus [that causes COVID-19] shortly before or right after getting the vaccine, and become ill from that exposure. But the vaccine cannot infect someone with COVID-19.
5. New vaccines usually take >5 years to be developed. How did a vaccine using a new technology become available under 1 year?
There are numerous factors that led to this vaccine being produced in a record time. Many of these are listed below:
6. How many people received the vaccine in clinical trials?
- mRNA technology for vaccines already exists, and mRNA vaccines for other diseases, including influenza, RSV, Rabies, and Zika virus, are also currently in clinical studies.
- Scientists had already been working with vaccines for coronaviruses since 2003 for SARS, and then again in 2013, with MERS.
- Because this technology already existed, once scientists had the DNA sequence of the virus in January 2020, the draft of the mRNA vaccine was able to be produced very shortly after the virus genome was published.
- mRNA vaccines are much easier to produce than other types of vaccines. Fewer steps are required in the manufacturing process, including that the vaccine requires no incubation time, allowing manufacturers to produce a larger volume more quickly. A comparison could be made that the vaccine is “produced” or “printed,” rather than “grown.”
- Many people quickly volunteered to participate in trials, which allowed them to be started immediately.
- Manufacturing of the vaccine was heavily underway before the approval process had been completed. This is because federal government agreed to pre-purchase a large number of vaccine doses that were strong candidates. Therefore, for companies developing the vaccine, there was less risk to them that they would lose money from manufacturing vaccine that would not be used.
- Vaccines for COVID have received higher priority than many vaccine candidates for other diseases, which means that more resources have been dedicated to this process, such as ensuring that data related to this vaccine are reviewed rapidly.
- Overall, this was well-funded science, backed by the urgent need to save lives and restore livelihoods.
More than 40,000 people were part of the Pfizer vaccine trial. Nearly 40% were between 56 and 85, and there was a diverse patient population--spanning 6 different countries--enrolled.
More than 30,000 people were part of the Moderna vaccine trial, all of whom were in the United States. More than 7,000 patients were over 65, and 5,000 were under 65 but had high-risk chronic conditions. This study also had a very diverse patient population that is fairly similar to the diversity of the US population.
7. How well do the vaccines work?
Both vaccines have an efficacy rate of about 95% after the 2nd
dose. This means that at the time the initial results of the study had been completed, nearly 20 times as many people had become infected with COVID-19 in the placebo group compared with the study group. In the case of the Pfizer vaccine, this was 162 infections in the placebo group and 8 infections in the study group.
Data from the Pfizer trial shows that strong protection from the virus can start to be seen 10-14 days after the first vaccination. After 10-14 days from the first vaccination, very few people were infected with COVID-19, while the placebo group cases rose steadily over time. Vaccine effectiveness was excellent regardless of age, race, or sex.
The Moderna vaccine is also highly effective among all groups and has a similar timeline of when strong protection from COVID-19 can be expected. Although there is potentially slightly lower efficacy of the Moderna vaccine in patients 65 and older based compared with those younger than 65 based on raw percentages, the number of overall cases in the over 65 group was too small to determine if there is a true difference.
8. If the vaccine works fairly well after the first dose, why do we need to get a second dose?
The number of antibodies produced after the second vaccination dramatically increases compared to receiving only a single dose. While a single dose certainly offers some protection, the second dose is expected to offer significantly longer protection. A much larger number of people are able to be infected after the first dose than after the second dose.
9. Do I need to get the vaccine if I already had COVID?
Vaccination is recommended for those who have already had COVID-19. There is limited data on how long immunity lasts after an infection. The Indiana Department of Health and many other organizations are currently recommending to wait at least 3 months after being diagnosed with COVID to get the vaccine, but it is not a mandate. Those who are high-risk themselves, or live or work with those who are, can consider earlier vaccine after their infection.
10. Will this be a one-time vaccination, or an annual vaccine?
There has not been enough time to evaluate exactly how long antibodies are expected to last, so it is unknown at this time whether this will be an annual vaccination.
11. If I am vaccinated, can I spread COVID-19 to people who haven’t been vaccinated?
Limited information about transmission from vaccinated patients has been published. The Moderna vaccine is known to reduce both symptomatic and asymptomatic cases, while asymptomatic case data has not been published yet by Pfizer.
At this time the recommendation is to continue with the same precautions (masking, social distancing, etc.) until further guidance is available.
12. Can you donate blood after receiving the vaccine? How long afterwards do you need to wait before donating blood?
Here is what the Red Cross has on their website
13. Is there a reason to abstain from alcohol in the days around being vaccinated?
- The Red Cross is following FDA blood donation eligibility guidance for those who receive a COVID-19 vaccination, and deferral times may vary depending on the type of vaccine an individual receives.
- There is no deferral time for eligible blood donors who are vaccinated with an inactivated or RNA based COVID-19 vaccine manufactured by Moderna or Pfizer.
- If you’ve received a COVID-19 vaccine, you’ll need to provide the manufacturer name when you come to donate.
- Upon vaccination, you should receive a card or printout indicating what COVID-19 vaccine was received, and we encourage you to bring that card with you to your next donation. The following eligibility guidelines apply to each COVID-19 vaccine received, including boosters.
Overall, excessive alcohol consumption inhibits the immune response in general—not just related to the vaccine. Don’t drink excessively around the time of being vaccinated. Having a glass or two of wine isn’t going to be a problem.
Note that alcohol usage was not an exclusion from the vaccine studies, so people with varying degrees of alcohol consumption were included in the study. That means that varying alcohol usage is reflected in the efficacy results of study.
14. Will the current vaccines protect us against the new COVID-19 variants being discovered?
There is not currently efficacy data for the current mRNA vaccines (Pfizer and Moderna) for the prevention of COVID disease from some of the new variants from South Africa, the UK, etc. It is likely we will have this information at a later date.
There is, however, data from laboratory experiments testing the efficacy of these vaccines. While the antibody response was found to be lower than the original strain, the mRNA vaccines are still expected to be protective against these variants, though it is unknown if it will still be >90%.
Both companies are working on developing booster shots to address any concerns with COVID variants. Fortunately, mRNA vaccines in particular are designed in such a way that it is easier to study and produce vaccines against new COVID variants compared with some of the other types of vaccines available.
At this time, the UK and South African strains are only a very small minority of cases in the US. Because variants are more likely to happen with more virus replication, the faster we can vaccinate as many people as possible (and follow other appropriate prevention measures), the lower we can reduce the volume of these variants, and the risk these variants pose.
15. Once I’m vaccinated, if I have an antibody test (such as through a blood donation), will I then have COVID-19 antibodies as a result of the vaccine?
Current antibody tests for SARS-CoV-2 (the virus that causes COVID-19) are not designed to detect the antibody response from the vaccine. That’s because the current vaccines create an antibody response to the SARS-CoV-2 spike protein only—not the overall virus itself (like in the case of natural immunity from infection).
However, tests are in development for the detection of the spike protein antibodies, to help measure the vaccine response.
Additional "Frequently Asked Questions" can be found on the Centers for Disease Control and Prevention website: https://www.cdc.gov/coronavirus/2019-ncov/vaccines/faq.html