At last, at last. After an excruciating year of coronavirus pandemic, an amazing milestone has been reached: COVID vaccination has begun!
On December 11, 2020, the FDA granted an emergency use authorization (EUA) to Pfizer’s COVID-19 vaccine. Moderna was granted a similar EUA on December 18, 2020.
On February 27, 2021, the FDA granted emergency use authorization to Johnson & Johnson’s COVID vaccine. Unlike the Pfizer and Moderna vaccines, which require two injections spaced about a month apart, the J&J vaccine only requires one injection.
Of course, it doesn’t mean that everything will be back to normal within the next few weeks. But vaccination is what will enable us to eventually pull out of the danger and disruption the pandemic is causing.
Although it’s exciting to see COVID vaccination start to take place in the U.S., it also raises a lot of questions for people.
In this article, I’ll summarize what I think is most important for older adults and families to know about coronavirus vaccination.
In particular, I want to address the question of efficacy (does it work?) and safety (is it dangerous?), specifically for older adults.
So I’ve recorded a short video presentation about how I assess whether the COVID vaccine (or other treatment) is effective in older adults, especially those over age 85 and those in nursing homes. I also have summarized some key vaccine information below.
In this video, I review the data for Pfizer’s vaccine, and I show you how you can assess the data on older adults when the data for upcoming vaccines is released.
What’s Most Important to Know About COVID Vaccination
What COVID vaccines are currently available?
You can see which COVID vaccines have been approved for use in the U.S. on the FDA’s COVID-19 Vaccines page: FDA COVID-19 Vaccines.
As of March 5, 2021, in the U.S., three COVID-19 vaccines have received an Emergency Use Authorization (EUA) from the FDA: Pfizer, Moderna, and Janssen (which is the pharmaceutical branch of Johnson & Johnson).
Dozens of other vaccines are under development worldwide, of which some are in “Phase 3,” in which the vaccine is given to thousands of people to test it for efficacy and safety. You can see a list of vaccines in Phase 3 on the NYTimes Coronavirus Vaccine Tracker page, which also includes a helpful summary of the vaccine approval process.
Once a vaccine receives the FDA’s Emergency Use Authorization, it still needs to be distributed before it can be available to individuals. Manufacturing the millions of necessary doses is also a challenge. For the time being, many of us will find that an authorized COVID vaccine is still not easily available to us.
About the mRNA COVID Vaccines (Pfizer and Moderna)
How the Pfizer and Moderna COVID vaccines work
The Pfizer and Moderna vaccines use a new approach for vaccination: messenger RNA (“mRNA”). This technology has never before been used in a licensed vaccine. But it seems to offer several advantages over pre-existing vaccine technology.
Whereas most vaccines work by injecting a person with a killed virus or portion of virus, mRNA vaccines use a totally different approach: they contain limited instructions that prompt the body’s cells to create copies of the COVID spike protein component (but not the whole virus).
The body’s immune system then recognizes the COVID spike protein as foreign, and builds up immunity. This means that when the body later encounters the complete COVID virus during an infection, it can ramp up quickly and defeat the virus before the person feels ill, or becomes seriously ill.
So, it’s impossible to get COVID from the mRNA COVID vaccines, because they don’t inject killed or weakened COVID, and the injected instructions cannot cause the body to create complete functioning COVID virus.
Another advantage of the new mRNA technology is that vaccine doses can be manufactured much more quickly.
You can learn more about these mRNA vaccines here: CDC: Understanding mRNA COVID-19 Vaccines
For the Pfizer and Moderna vaccines, two doses are required (3 and 4 weeks apart, respectively).
mRNA COVID Vaccine Efficacy in Older Adults: What we know from the trials so far
To date, the best information publicly available comes from the Pfizer phase 3 trial data, which was published in the New England Journal of Medicine (NEJM) on December 10, 2020, and the Moderna phase 3 trial data, which was published on December 30, 2020.
As was widely reported by the press, the Pfizer trial included about 43000 participants, who were randomized to get the Pfizer COVID vaccine or a placebo injection. During a follow-up period of a few months, there were 8 cases of Covid-19 among vaccine recipients and 162 cases among placebo recipients. The authors concluded that the vaccine was 95% effective in preventing Covid-19.
But before you assume that you — or your aging parent — will be 95% protected by the vaccine: it’s extremely important to take a good look at the study data, to find out: how many people like you were studied, and what were the results in that group?
Being a geriatrician, I always want to know how many older adults were included in a study, what was the age breakdown of older participants (because the average 65-year-old is medically fairly different from the average 85-year-old), and what happened with those participants.
Here’s what I found out, for the Pfizer trial:
- The median age of participants was 52 years, and 42% of participants were older than 55 years of age. The age range of participants was 16-91.
- COVID cases and vaccine efficacy results are reported for four age ranges (see Table 3):
- 16-55 years (19852 people) –> 5 cases (vaccine) vs 114 cases (placebo) –> 95.6% efficacy (statistically likely range: 89.4–98.6%)
- >55 years (15043 people) –> 3 cases (vaccine) vs 48 (placebo) –> 93.7% (statistically likely range: 80.6–98.8%)
- >65 years (7728 people) –> 1 case (vaccine) vs 19 (placebo) –> 94.7% efficacy (statistically likely range: 66.7–99.9)
- >75 years (1559 people) –> zero cases (vaccine) vs 5 cases (placebo) –> 100.0% efficacy (statistically significant range: −13.1–100.0%)
Please note that it’s not a typo: for participants aged 75 years or older, they are reporting a statistically likely efficacy range of negative 13% to 100%. (!)
What does this result mean? Since the statistically likely efficacy range includes the number zero, it means it’s possible the vaccine has zero efficacy.
But honestly, that’s unlikely. The data right now is showing this large efficacy range because in practical terms, they didn’t have enough people aged 75+ catch COVID during the study period. (This may be because everyone in this age group was being careful to minimize their COVID exposure.) So, there was not enough data to determine how well the vaccine works in this age group.
It also means that for the time being, we don’t know how well the Pfizer vaccine works in older adults aged 75+. And we really don’t know how well it works in people aged 85-90+. We don’t even know how many people aged 85+ were in the study, but probably it was a small number.
Most vaccines, such as the influenza vaccine, tend to work less well in older adults because of an aging immune system. (This is why vaccine makers have designed flu vaccines specifically for older adults.)
At this time, I think it’s likely that the Pfizer vaccine is effective in the most vulnerable older adults (e.g. those in nursing homes and those over age 85). It won’t be AS effective as in younger people, but it’s likely better than not being vaccinated at all.
The vaccine also appears to be safe — certainly safer than catching COVID.
Of note, a recently published study of the Pfizer vaccine efficacy under real-world conditions in Israel, which reported real-world vaccine efficacy of over 90%, excluded nursing home residents from the study, and did not report effectiveness in people over age 80. So for now, we are still left with good reason to believe the COVID vaccine is effective in adults over age 75 yet it’s unclear just how effective.
What about the efficacy of the Moderna vaccine?
The Moderna data was overall similar to the Pfizer data. They also had a limited number of participants over age 75, and so could not draw stastically significant conclusions regarding the efficacy of the vaccine in people over age 75. The peer-reviewed Moderna vaccine study results published in the New England Journal are here.
However, the more interesting data is what Moderna submitted to the FDA when requesting emergency approval, which can be viewed here.
- In Table 17 (page 29), you can see that in people aged 65+, the point estimate for vaccine efficacy was 86.4% (95% likely range of 61.4 – 95.5%), compared to an efficacy of 95.6% (range 90.6%, 97.9%) in people age 18 to under 65.
- This is still a very good efficacy, but note that it has dropped compared to a younger population. And…the aged 65+ group was most people aged 65-75.
- You can see the number of participants aged 75+ and the vaccine efficacy results in Table 10 (page 24).
- The number of people over age 75 was quite small (about 1300 overall) and there were only 3 COVID cases in the vaccinated group.
- So the posted efficacy rate of 100% is not statistically significant (which is why they don’t provide a range).
Needless to say, the participants in the vaccine trials who were aged 75+ are overall much younger and healthier than people in nursing homes, and should be assumed to have a better immune system response to vaccines than even a healthy 90 year old will have.
If you are wondering why there weren’t more people aged 75+ in the trials, see this interview with geriatrician Dr. Sharon Inouye, of Harvard: Why Aren’t Highest-Risk People Better Represented in COVID Vaccine Trials?
In my opinion, the biggest risk in vaccinating frail older adults is that people may overestimate the associated protection and then take fewer precautions around these older adults. So even if all residents of a nursing home are vaccinated, I hope that all the staff will agree to be vaccinated as well, and that everyone continues to take precautions until the levels of COVID community transmission finally drop down.
Do the Pfizer and Moderna vaccines protect against the new variants of COVID?
As of late January 2021, the CDC has become aware of several COVID variants that appear to be more contagious than usual. These seem to have originated overseas but appear to be circulating in the United States. The variants include:
- B.1.1.7 (first identified in the U.K.)
- B.1.351 (first identified in South Africa)
- P.1. (first identified in Brazil)
The vaccine makers are actively studying how well their vaccines protect again these variants. Preliminary evidence suggests that the Pfizer and Moderna vaccine work less well against the “South Africa variant”, but still provide a fair amount of protection.
It is possible that the vaccine makers will offer “booster shots” later in the year, to provide better protection against the variants.
Are the Pfizer and Moderna COVID vaccines safe?
In general, it appears to be quite safe and there were very few true severe problems noted in the study.
Now, it’s important to note that it was quite common for vaccine recipients to feel unwell after vaccination, especially after the second dose. The most common symptoms were fatigue and headache, and some people experienced fever, as well.
These are signs that the immune system is responding to the vaccine! (Which is why they occurred less often in older participants than younger ones.) So these should not be taken as a sign that the vaccine is dangerous, or not worthwhile.
For more on the Pfizer vaccine’s safety data, see my video above.
About the Johnson & Johnson COVID Vaccine
March 2021 update: As the J&J vaccine was just recently approved, I am still working my way through the data, and will update this section further when I get a chance.
Reviewing the J&J vaccine data is more complicated in that the Phase 3 trial was conducted in three countries (the US, Brazil, and South Africa), and also took place in the winter of 2020-2021, when some areas had COVID variants spreading.
The trial data submitted to the FDA can be viewed here: FDA Briefing Document: Janssen Ad26.COV2.S Vaccine for the Prevention of COVID-19.
A good summary of the J&J vaccine, including how it’s different from the Pfizer and Moderna vaccines, is here: How does the Johnson & Johnson vaccine work? When is it available? What to know about the new shot.
I will update this article soon with more details, but the bottom line is that although the posted overall efficacy rate appears to be lower (72% in the US) than that of the mRNA vaccines, the J&J vaccine is still quite effective overall and after 28 days, it had good efficacy (83%; see table 16) in preventing severe/critical COVID.
The vaccine also appeared to be safe. Similar to the previously approved COVID vaccines, many vaccine recipients did experience side effects such as headache, fatigue, and body aches, and these were more common in younger recipients.
So far, I have not yet found very detailed data on the vaccine efficacy in people over age 75; they are mentioned in some results tables (e.g. table 12) but there does not seem to be enough data to draw an efficacy conclusion.
Updates on Vaccine Safety Data:
Update January 29, 2021: The CDC’s Advisory Committee on Immunization Practices (ACIP) reviewed COVID vaccine safety data in a meeting on January 27, 2021. You can view the meeting slides and safety data here. This meeting included data on the immunization of nursing home residents (slides 39-41). These vaccinations used Pfizer and Moderna vaccines
The safety data so far, for nursing home residents, is reassuring. As the slides explain, so far it doesn’t look like people in nursing homes are more likely to die within after vaccination, compared to nursing home residents who are not vaccinated.
Who shouldn’t be vaccinated against COVID?
At this time, there are not many specifics on who should not be vaccinated, provided a vaccine is approved for your age group. (Neither the Pfizer or the Moderna vaccine have an emergency authorization for children.)
As of January 2021, there have been a relatively small number of severe allergic reactions, which the FDA is investigating. So people with a history of anaphylactic allergic reactions should probably check with their health providers before pursuing vaccination.
That said, with millions of vaccine doses being distributed over the next several month, guidelines are likely to rapidly evolve, regarding who should not be vaccinated, or who should be vaccinated with caution. For accurate information on this topic, I recommend reputable information sources, such as the FDA and the CDC’s COVID information pages. (See Resources, below.)
My current recommendation for COVID vaccination
As of March 5, 2021, I think that for most people, it’s best to accept vaccination for COVID, if you have the opportunity to do so. I also would not recommend worrying about which vaccine to get; at this point, any vaccine is better than risking COVID.
- The Pfizer and Moderna vaccines appears to be quite effective, especially in people up to age 75.
- The Johnson and Johnson vaccine is quite effective as well.
- Even though it’s unclear exactly how effective these vaccines are in people over age 75, they almost certainly provide some protection.
- Remember, this is the age group in which COVID is mostly likely to cause hospitalization or death; 60% of all US COVID deaths have occurred in people over age 75.
- COVID cases and deaths in US nursing homes appear to have decreased since the vaccination campaign started.
- So far there is no reason to believe these vaccine are unsafe or likely to cause lasting harm.
- Until COVID rates drop way, way, down, the risks of catching and transmitting COVID should vastly outweigh the potential discomfort of vaccination or very small risk of an adverse reaction.
What to remember if you — or your loved one — is over age 75:
I do think you should accept vaccination, but please please do not assume you will be 95% protected from COVID.
Until adequate research is done, we will not know how effective these vaccines are for our most vulnerable older adults. COVID is also mutating and although so far the current vaccines appear protective against variants, that could change.
So it’s important to keep taking precautions and continuing efforts to reduce COVID exposure, such as masks, physical distancing, and avoiding indoor gatherings.
We can also protect nursing home residents and other vulnerable older adults by encouraging all younger adults around them to accept vaccination.
Please take care, stay safe, and consider vaccination once it’s available to you!
- FDA (Food & Drug Administration):
- COVID-19 Vaccines
- FDA: Emergency Use Authorization for Vaccines Explained
- FDA Briefing Document: Pfizer-BioNTech COVID-19 Vaccine (Dec 10, 2020)
- FDA Briefing Document: Moderna COVID-19 Vaccine (Dec 17, 2020)
- FDA Briefing Document: Janssen Ad26.COV2.S Vaccine for the Prevention of COVID-19. (Feb 26, 2021)
- How CDC Is Making COVID-19 Vaccine Recommendations
- Frequently Asked Questions about COVID-19 Vaccination
- Provisional COVID-19 Death Counts by Sex, Age, and State
- New Variants of the Virus that Causes COVID-19
- CDC Advisory Committee on Immunization Practices: COVID-19 vaccine safety update (January 27, 2021)
- CDC advisory panel’s lone dissenter on why long-term care residents shouldn’t receive Covid-19 vaccine first
- New England Journal of Medicine:
- Safety and Efficacy of the BNT162b2 mRNA Covid-19 Vaccine (12/10/20 publication of the Pfizer vaccine phase 2/3 trial data)
- Efficacy and Safety of the mRNA-1273 SARS-CoV-2 Vaccine (12/30/20 publication of the Moderna vaccine phase 3 trial data)
- New York Times:
- Washington Post: How does the Johnson & Johnson vaccine work? When is it available? What to know about the new shot.
- MedPageToday “Track the Vax” Podcast Interview transcript: Why Aren’t Highest-Risk People Better Represented in COVID Vaccine Trials?
- COVID Cases In Long Term Care Facilities Declining As New Data Indicates The Vaccine May Reduce Spread
This article was first published on Dec 18, 2020, and was last updated by Dr. Kernisan on March 5, 2021.