COVID Vaccination in Aging: How to Know if it Works

At last, at last.After an excruciating year of coronavirus pandemic, an amazing milestone has been reached: COVID vaccination has begun!OnDecember 11, 2020, the FDA granted an emergency use authorization (EUA) to Pfizers COVID-19 vaccine.So now, its possible to vaccinate people who are not part of a trial studying the new vaccine.

(Modernas vaccine is expected to get its EUA very soon, as well.)Of course, it doesnt 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 its 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, Ill 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 Ive 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 Pfizers vaccine, and I show you how you can assess the data on older adults when the data for upcoming vaccines is released.(For a short tutorial on how to slow down the video or search the transcript, seehere.)Whats Most Important to Know About COVID VaccinationWhat COVID vaccines are currently available?You can see which COVID vaccines have been approved for use in the U.S.

on the FDAs COVID-19 Vaccines page: FDA COVID-19 Vaccines.As ofDecember 17, 2020, only Pfizers vaccine has received an Emergency Use Authorization (EUA).However, the FDA has recommended that Modernas vaccine be granted an EUA as well, which will likely happen soon.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 FDAs 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.How the Pfizer and Moderna COVID vaccines workThe 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 bodys cells to create copies of the COVID spike protein component (but not the whole virus).The bodys 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, its impossible to get COVID from the mRNA COVID vaccines, because they dont 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 VaccinesFor the Pfizer and Moderna vaccines, two doses are required (3 and 4 weeks apart, respectively).COVID Vaccine Efficacy in Older Adults: What we know from the trials so farTo 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.As was widely reported by the press, the 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: its 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.Heres what I found out: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: 89.498.6%)>55 years (15043 people) > 3 cases (vaccine) vs 48 (placebo) >93.7% (statistically likely range: 80.698.8%)>65 years (7728 people) > 1 case (vaccine) vs 19 (placebo) >94.7% efficacy (statistically likely range: 66.799.9)>75 years (1559 people) > zero cases (vaccine) vs 5 cases (placebo) >100.0% efficacy (statistically significant range: 13.1100.0%)Please note that its 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 its possible the vaccine has zero efficacy.But honestly, thats unlikely.

The data right now is showing this large efficacy range because in practical terms, they didnt 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 dont know how well the Pfizer vaccine works in older adults aged 75+.And we really dont know how well it works in people aged 85-90+.

We dont 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 its 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 wont be AS effective as in younger people, but its likely better than not being vaccinated at all.The vaccine also appears to be safe certainly safer than catching COVID.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.Is the Pfizer COVID vaccine safe?In general, it appears to be quite safe and there were very few true severe problems noted in the study.Now, its 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 vaccines safety data, see my video above.Who shouldnt 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 December 18th, there have been a very 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 few weeks, 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 CDCs COVID information pages.

(See Resources, below.)My current recommendation for COVID vaccinationAs of December 18th, 2020, I think that for most people, its best to accept vaccination for COVID, if you have the opportunity to do so.Thats because:The Pfizer vaccine appears to be quite effective, especially in people up to age 75.Even though its unclear how effective it is in people over age 75, it almost certainly provides 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.So far there is no reason to believe the vaccine is unsafe or likely to cause 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 the vaccine is for our most vulnerable older adults.So its 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 its available to you!Resources:FDA (Food & Drug Administration):COVID-19 VaccinesFDA: Emergency Use Authorization for Vaccines ExplainedCDC:How CDC Is Making COVID-19 Vaccine RecommendationsFrequently Asked Questions about COVID-19 VaccinationProvisional COVID-19 Death Counts by Sex, Age, and StateCDC advisory panels lone dissenter on why long-term care residents shouldnt receive Covid-19 vaccine firstNew 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)New York Times:COVID-19 Vaccine TrackerF.D.A.Clears Pfizer Vaccine, and Millions of Doses Will Be Shipped Right Away