If Covid Vaccines Are So Effective, Why Do I Need a Booster Shot?

By Julie Appleby, Kaiser Health News

The politicization of covid vaccines — and just about everything else having to do with the pandemic — has led to confusion, if not utter fatigue.

And some posts circulating on social media — like this slickly edited piece on YouTube — seem to build on these feelings, attempting to cast doubt on the effectiveness of the vaccines.

The video intersperses comments from White House medical adviser Dr. Anthony Fauci extolling their protectiveness with screenshots of news headlines, starting with those citing 100% effectiveness, then moving through others reporting sharply lower percentages. Set to the rapidly increasing tempo of the orchestral piece “In the Hall of the Mountain King,” the video ends with headlines about drug company profits.

But slowing the video to parse the headlines reveals more complexity. Some are reporting on studies that looked only at infection rates; others, more serious outcomes, including hospitalization and death. Some are about vaccines not offered in the U.S. In short, the video fosters misperceptions by mixing together dissimilar data points and leaving out key details.

Still, one can’t help but wonder what’s really going on with effectiveness — and is any of it a surprise?

If you don’t read any further, know this: No vaccine is 100% effective against any disease. The covid shots are no exception. Effectiveness in preventing infection — defined as a positive test result — appears in some studies to wane sharply the more time that goes by after completing the one- or two-shot regimen.

But on key measures — prevention of serious illness, hospitalization and death — real-world studies from the U.S. and abroad generally show protection weakening slightly, particularly in older or sicker people, but remaining strong overall, even with the rise of the more infectious delta variant of the covid virus.

The bottom line? Getting vaccinated with any of the three vaccines available in the U.S. reduces the chance of getting infected in the first place, and significantly cuts the risk of hospitalization or death if you do contract covid-19. The Centers for Disease Control and Prevention recently published a study showing fully vaccinated people were more than 10 times less likely to die or be hospitalized than the unvaccinated.

“When it comes to what matters, vaccines hold up really well,” said Dr. Amesh Adalja, an infectious-disease physician and senior scholar at the Johns Hopkins Center for Health Security. “They were designed to tame the virus.”

What do “efficacy” and “effectiveness” really mean?

Before a drug or vaccine is greenlighted by federal regulators, it is tested on volunteers randomly assigned to get either the product or a placebo. Then researchers compare how the groups fare. In the case of a vaccine, they look at how well it prevents infection, and whether it protects against serious illness, hospitalization or death. Those clinical trial results are often referred to as efficacy measures.

In the real world, however, a drug or vaccine’s performance is affected by numerous factors, including a much larger population receiving it, some of whom have underlying conditions or socioeconomic circumstances different from those in the clinical trial. That real-world performance measure is called effectiveness.

When authorized for emergency use following clinical trials, both the Pfizer-BioNTech and Moderna two-dose vaccines reported efficacy against symptomatic illness in the mid-90% range. The Johnson & Johnson single-dose shot — which was tested later, when there were more variants — reported overall efficacy in the high 60% range.

So, all three vaccines exceeded the 50% threshold health officials sought as a minimum for efficacy. Keep in mind, also, that the annual influenza vaccine’s real-world effectiveness is often 40% to 50%.

Another point: 95% effectiveness doesn’t mean 95% of vaccinated people will never get infected. What it means is that a fully vaccinated person exposed to the virus faces only 5% of the risk of infection compared with an unvaccinated person.

Have the effectiveness numbers changed?

Yes, decline in effectiveness against infection is seen in some studies. A few have also raised concerns that protection against serious illness may also be diminished, particularly in older people and patients with underlying medical conditions.

Reasons for the decline vary. First, when the vaccines were authorized, much of the U.S. was under tighter pandemic-related stay-at-home rules. Nearly a year later, restrictions — including mask rules — have loosened in many areas. More people are traveling and going into situations they would have avoided a year ago. So, exposure to the virus is higher.

Some studies from the U.S. and abroad show that time elapsed since vaccination also plays a role. The Lancet recently published a study of more than 3.4 million Kaiser Permanente members, both vaccinated and not, reviewing the effectiveness of the Pfizer vaccine. It showed an overall average 73% effectiveness against infection during the six months after inoculations, and an overall 90% effectiveness against hospitalization.

But protection against infection declined from 88% in the month after full vaccination to 47% at five to six months. Time since vaccination played a larger role than any changes in the virus itself, the researchers concluded.

“It shows vaccines are highly effective over time against severe outcomes,” said lead author Sara Tartof, an epidemiologist with the Department of Research and Evaluation for Kaiser Permanente Southern California. “Against infection, it does decline over time, something that is not unexpected. We have boosters for many other vaccines.”

The virus, too, has mutated.

“Along came delta,” said Dr. William Schaffner, a professor of preventive medicine at Vanderbilt University School of Medicine. “Because this virus was so highly contagious, it changed the outcomes slightly.”

And some vaccinated people can fall seriously ill with covid, or even die, especially if they have an underlying medical problem, as was the case with Gen. Colin Powell. He died of covid complications even though he was fully vaccinated — likely because he also had a blood cancer called multiple myeloma, which can lower the body’s response to an invading virus as well as to vaccination.

Why are they recommending booster shots?

Most scientists, researchers and physicians say the vaccines are working remarkably well, especially at preventing serious illness or death. But it’s not unusual to need more than one dose.

Vaccines for shingles and measles both require two shots, while people need to be revaccinated against tetanus every 10 years. Because influenza varies each year, flu shots are annual.

Immune response is often better when vaccines are spaced apart by a few months. But during the rollout of the covid vaccines, so many people were falling ill and dying of covid each day that the Food and Drug Administration and CDC decided not to delay, but to authorize the first and second doses within about a month of each other.

“We learn as we go along,” said Schaffner. “It was always anticipated there might have to be follow-up doses.”

Now, the recommendations call for a second dose for anyone who received a J&J shot at least two months prior. For those who received the two-dose Pfizer or Moderna vaccine, the recommendation is to wait six months after the second dose to get a booster, which is currently recommended for those who are 65 and older; have any of a variety of underlying health conditions; live in congregate settings, such as nursing homes; or have jobs that put them at higher risk. The booster recommendations may expand in the coming months.

Kaiser Health News is a national newsroom that produces in-depth journalism about health issues.

Experts Debate Need for Covid Booster Shots

By Rachana Pradhan, Kaiser Health News

The Biden administration’s plans to make covid-19 booster shots available next month has drawn a collective scream of protest from the scientific community.

As some scientists see it, the announcement is rash and based on weak evidence, and they worry it could undercut confidence in vaccines with no clear benefit of controlling the pandemic. Meanwhile, more information is needed on potential side effects or adverse effects from a booster shot, they say.

Perhaps even worse, the announcement has fueled deeper confusion about what Americans need to do to protect themselves from covid.

“I think we’ve scared people,” said Dr. Paul Offit, director of the Vaccine Education Center at Children’s Hospital of Philadelphia and an adviser to the National Institutes of Health and the Food and Drug Administration.

“We sent a terrible message,” he said. “We just sent a message out there that people who consider themselves fully vaccinated were not fully vaccinated. And that’s the wrong message, because you are protected against serious illness.”

As of Thursday, 51% of the U.S. population was fully vaccinated, Centers for Disease Control and Prevention data shows. Biden administration officials ― citing data from Israel, a study from the Mayo Clinic that is not yet peer-reviewed and new CDC studies ― say it’s necessary to plan for boosters to prevent a worsening of the pandemic as the delta variant powers a surge in cases and overwhelms hospital intensive care units.

In essence, officials are caught between a rock and a hard place ― trying to be prepared while simultaneously not undermining messaging about how well the existing vaccines work.

Virus Unpredictable

Officials must weigh two unknowns: the risks of moving ahead aggressively with booster shots versus the risks of waiting to learn much more about the virus and the power of the vaccines. The government’s normal path to regulatory approval is, by design, slow and deliberate. The virus has its own schedule, fast and unpredictable.

“Arguably, I think that the federal government is simply trying to stay ahead of the curve,” said Dr. Joshua Barocas, associate professor of medicine at the University of Colorado. But, he said, “I have not seen robust data yet to suggest that it is better to boost Americans who have gotten two vaccines than invest resources and time in getting unvaccinated people across the world vaccinated.”

Beginning in late September, boosters would be made available to adults (age 18 and up) eight months after they received the second dose of a Pfizer-BioNTech or Moderna covid vaccine, President Joe Biden said. But his plan comes with big caveats: It does not yet have the blessing of a CDC advisory panel, and the FDA has not authorized boosters for all adults.

The urgent question is whether the vaccines are losing their power against covid.

“We are concerned that this pattern of decline we are seeing will continue in the months ahead, which could lead to reduced protection against severe disease, hospitalization and death,” Surgeon General Vivek Murthy said.

But many scientists and public health experts say the data doesn’t demonstrate a clear benefit to the public in making booster shots widely available, and the Biden administration’s message confuses people about what the covid vaccines were designed to do.

“They’re not a force field. They don’t repel the virus from your body. They train your immune system to respond when you become infected … with the goal of keeping you out of the hospital,” said Jennifer Nuzzo, an epidemiologist and associate professor at the Johns Hopkins Bloomberg School of Public Health.

Meanwhile, questions abound. Will boosters for fully vaccinated adults make the virus less transmissible ― that is, slower or less likely to spread to others?

“I certainly hope that’s the case … but the bottom line, with full transparency, we don’t know that right now,” Dr. Anthony Fauci, Biden’s chief medical adviser, said Wednesday.

What about side effects? “It would be nice to understand what side effects people have after their third dose,” Nuzzo said.

“We don’t have any reason to believe, based on the safety profile of the vaccine itself, that we’re going to see significant adverse events with booster shots,” Barocas said. However, those things are “just now being studied.”

The concerns are real. While serious side effects from covid vaccines have been rare, some have caused alarm ― including mRNA vaccines being linked to cases of myocarditis, or inflammation of the heart.

“At the individual level, we need to know the side effect profile of a 3rd dose, especially in younger people. Until now, the benefits of vaccination have far outweighed the potential side effects,” Dr. Jeremy Faust, an emergency medicine physician at Brigham and Women’s Hospital in Boston, wrote in a blog post outlining why he was skeptical about a plan to give boosters to everyone.

Vaccines Still Effective

Even in light of the new CDC studies published Wednesday, experts say one thing is clear: The vaccines still work very well at what they were meant to do, which is to protect people against the worst outcomes of getting infected with the virus.

One study, relying on data from 21 hospitals in 18 states, found no significant change in the vaccines’ effectiveness against hospitalization between March and July, which coincides with delta becoming the prevalent covid strain. Another, using data from New York, also found the vaccines highly effective in preventing hospitalization, even as there was a decline in effectiveness against new infections. The third, evaluating the Pfizer and Moderna vaccines in nursing home residents, saw a drop in how effective they were at preventing infection ― but the research didn’t distinguish between symptomatic and asymptomatic cases.

“It’s like we’re engaged in friendly fire against these vaccines,” Nuzzo said. “What are we trying to do here? Are we just trying to reduce overall transmission? Because there’s no evidence that this is going to do it.”

Fauci, in outlining the case for boosters, highlighted data showing that antibody levels decline over time and higher levels of antibodies are associated with higher vaccine efficacy. But antibodies are only one component of the body’s defense mechanisms against a covid infection.

When the antibodies decrease, the body compensates with a cellular immune response. “A person who has lost antibodies isn’t necessarily completely susceptible to infection, because that person has T-cell immunity that we can’t measure easily,” said Dr. Cody Meissner, a specialist in pediatric infectious diseases who sits on the FDA’s vaccine advisory panel.

John Wherry, director of the Penn Institute of Immunology at the University of Pennsylvania, recently published a study finding that the mRNA vaccines provoked a strong response by the immune system’s T cells, which researchers said could be a more durable source of protection. Wherry is working on a second study based on six months of data.

“We’re seeing very good durability for at least some components of the non-antibody responses generated by the vaccines,” he said.

For protection against serious disease, “really all you need is immunological memory, and these vaccines induce immunological memory and immunological memory tends to be longer-lived,” Offit said. Federal scientists also are studying T-cell response, Fauci said.

FDA Approval Needed

Pfizer and Moderna have said they think boosters for covid will be necessary. But it’s up to the government to authorize them. Federal officials say they are sifting through new data from the companies and elsewhere as it becomes available.

There’s not a deep playbook for this: Emergency use authorization, or EUA, of vaccines has been sparingly used. The FDA has already amended Pfizer’s prior EUA clearance twice, first in May to expand the vaccines to adolescents 12 to 15 years old and, again, this month to allow immunocompromised people to obtain a third dose. The FDA did not respond to questions about the process for authorizing widespread booster shots.

Pfizer announced in July that it expects $33.5 billion in covid vaccine revenue this year. Its stock has risen 33% this year, closing at $48.80 Thursday. Moderna reported sales of $5.9 billion through June 30 for 302 million doses of its vaccine. The company’s stock has skyrocketed 236% year-to-date, closing at $375.53 Thursday.

In applying for emergency authorization, the FDA requires vaccine manufacturers to submit clinical efficacy data and all safety data from phase 1 and phase 2 clinical trials as well as two months of safety data from phase 3 studies. For full approval, the FDA requires manufacturers to submit six months of data.

Pfizer this week announced it has submitted phase 1 clinical trial data to the FDA as part of an evaluation for future approval of a third dose. The company said phase 3 results are “expected shortly.”

Pfizer said its preliminary trial results showed a third dose was safe and increased antibody levels against the original virus and the delta variant. Moderna found a third dose had safety results similar to a second dose and produced a strong antibody response. 

Typically, any distribution of shots would occur after the CDC’s Advisory Committee on Immunization Practices also developed recommendations. But with the Biden administration’s announcement about boosters, public health experts worry the message suggests the outcome is preordained.

“They have completely and unfairly jammed FDA and ACIP. They’ve left them no choice. If there’s no booster program, FDA gets blamed and that’s not appropriate,” said Dr. Nicole Lurie, a former senior Health and Human Services official in the Obama administration and U.S. director of the Coalition for Epidemic Preparedness Innovations, the global epidemic vaccines partnership.

Kaiser Health News is a national health policy news service. It is an editorially independent program of the Kaiser Family Foundation, which is not affiliated with Kaiser Permanente.

Don't Get Picky: All Three Covid Vaccines Highly Effective

By Arthur Allen and Liz Szabo, Kaiser Health News

When getting vaccinated against Covid-19, there’s no sense being picky. You should take the first authorized vaccine that’s offered, experts say.

The newest Covid vaccine on the horizon, from Johnson & Johnson, is probably a little less effective at preventing sickness than the two shots already being administered around the U.S., from Pfizer-BioNTech and Moderna.

The Food and Drug Administration authorized the Johnson & Johnson vaccine after reporting it showed about 66% effectiveness at preventing Covid illness in a 45,000-person trial. No one who received the vaccine was hospitalized with or died of the disease, according to the data released by the company and FDA. As many as 4 million doses could be shipped out of J&J’s warehouses beginning this week.

The J&J vaccine is similar to the shots from Moderna and Pfizer-BioNTech, but uses a different strategy for transporting genetic code into human cells to stimulate immunity to the disease. The Moderna and Pfizer-BioNTech vaccines were found in trials last fall to be 94% effective in preventing illness caused by Covid. They also prevented nearly all severe cases.

But the difference in those efficacy numbers may be deceptive. The vaccines were tested in different locations and at different phases of the pandemic. And J&J gave subjects in its trial only one dose of the vaccine, while Moderna and Pfizer have two-dose schedules, separated by 28 and 21 days, respectively. The bottom line, however, is that all three do a good job at preventing serious Covid.

“It’s a bit like, do you want a Lamborghini or a Chevy to get to work?” said Dr. Gregory Poland, director of the Mayo Clinic’s Vaccine Research Group, who was a paid consultant in the J&J study. “Ultimately, I just need to get to work. If a Chevy is available, sign me up.”

“From a personal and public health perspective, the best advice for now is to get whatever you can as soon as you can get it, because the sooner we all get vaccinated the better off we all are,” said Dr. Norman Hearst, a family doctor and epidemiologist at the University of California-San Francisco.

Of the 10 people who got severe disease in the Pfizer trial, nine had received a placebo, or fake vaccine; none of the 30 severe cases in the Moderna trial occurred in people who got the true vaccine. A month after receiving the Johnson & Johnson shot there were no deaths or hospitalizations in those who had been vaccinated.

“The real goal is to keep people out of the hospital and the ICU and the morgue,” said Dr. Paul Offit, director of the Vaccine Education Center at Children’s Hospital of Philadelphia. “This vaccine will do that well.”

J&J Vaccine Tested Against Variants

The data that Moderna and Pfizer-BioNTech presented to the FDA for their vaccines came from large clinical trials that took place over the summer and early fall in the United States. At the time, none of the new variants of Covid — some of which may be better at evading the immune responses produced by vaccines — were circulating here.

In contrast, the J&J trial began in September and was put into the arms of people in South America, South Africa and the United States. The J&J vaccine was 72% effective against moderate to severe Covid in the U.S. part of the trial, compared with 57% in South Africa, where a more contagious mutant virus is the dominant strain.

The Moderna and Pfizer-BioNTech vaccines might not have gotten the same sparkling results had they been tested more recently — or in South Africa.

“This vaccine was tested in the pandemic here and now,” said Dr. Dan Barouch, a Harvard Medical School professor whose lab at the Center for Virology and Vaccine Research at Beth Israel Deaconess Medical Center in Boston developed the J&J vaccine. “The pandemic is a much more complex pandemic than it was several months ago.”

The J&J vaccine appears to have some other advantages. First, it seems to cause fewer serious side effects like the fever and malaise suffered by some Pfizer-BioNTech and Moderna vaccine recipients. High fever and dehydration are particular concerns in fragile elderly people who “have one foot on the banana peel,” said Dr. Kathryn Edwards, scientific director of the Vanderbilt Vaccine Research Program. The J&J vaccine “may be a better vaccine for the infirm.”

Many people may prefer the J&J shot because “it’s one and done.” It’s easier for administrators too: just one appointment to schedule.

The J&J vaccine can also be stored in regular refrigerators, while the Pfizer and Moderna vaccines have to be stored in freezers and must be used or discarded within six hours after the vial is opened. Vials of the J&J vaccine can be restored in a refrigerator for later use if doses remain.

“Right now we have mass immunization clinics that are open but have no vaccine,” said Offit. “Here you have a single-dose regime with easy storage and handling.”

Ultimately, a person’s address — not their personal preference — may determine which vaccine they receive, said E. John Wherry, director of the Institute for Immunology at the University of Pennsylvania’s Perelman School of Medicine. He pointed out that the Johnson & Johnson vaccine is a simpler choice for rural areas.

“A vaccine doesn’t have to be 95% effective to be an incredible leap forward,” said Wherry. “When we get to the point where we have choices about which vaccine to give, it will be a luxury to have to struggle with that question.”

Kaiser Health News is a nonprofit news service covering health issues. It is not affiliated with Kaiser Permanente.

If I Have MS or an Autoimmune Condition, Should I Get the Covid Vaccine?

By Judith Graham, Kaiser Health News

As public demand grows for limited supplies of covid-19 vaccines, questions remain about the vaccines’ appropriateness for older adults with various illnesses, including those with cancer, multiple sclerosis or autoimmune conditions.

Recently, a number of readers have asked me whether older relatives with these conditions should be immunized. This is a matter for medical experts, and I solicited advice from several. All strongly suggested that people with questions contact their doctors and discuss their individual medical circumstances.

Experts’ advice may be helpful since states are beginning to offer vaccines to adults over age 65, 70 or 75, including those with serious underlying medical conditions. Twenty-eight states are doing so, according to the latest survey by The New York Times.

Q: My 80-year-old mother has chronic lymphocytic leukemia. Should she get vaccinated?

First, some basics. Older adults, in general, have responded extremely well to the two covid-19 vaccines that have received special authorization from the Food and Drug Administration. In large clinical trials sponsored by drug makers Pfizer and Moderna, the vaccines achieved substantial protection against significant illness, with efficacy for older adults ranging from 87% to 94%.

But people 65 and older undergoing cancer treatment were not included in these studies. As a result, it’s not known what degree of protection they might derive.

Dr. Tobias Hohl, chief of the infectious diseases service at Memorial Sloan Kettering Cancer Center in New York City, suggested that three factors should influence patients’ decisions: Are vaccines safe, will they be effective, and what is my risk of becoming severely ill from covid-19?

Regarding risk, he noted that older adults are the people most likely to become severely ill and perish from covid, accounting for about 80% of deaths to date — a compelling argument for vaccination.

Regarding safety, there is no evidence at this time that cancer patients are more likely to experience side effects from the Pfizer-BioNTech and Moderna vaccines than other people. “We are confident that these vaccines are safe for [cancer] patients,” including older patients, said Dr. Armin Shahrokni, a Memorial Sloan Kettering geriatrician and oncologist.

The exception, which applies to everyone, not just cancer patients: people who are allergic to covid-19 vaccine components or who experience severe allergic responses after getting a first shot shouldn’t get covid-19 vaccines.

In new guidelines published late last week, the National Comprehensive Cancer Network, an alliance of cancer centers, urged that patients undergoing active treatment be prioritized for vaccines as soon as possible. A notable exception:  Patients who’ve received stem cell transplants or bone marrow transplants should wait at least three months before getting vaccines, the group recommended.

The American Cancer Society’s chief medical and scientific officer, Dr. William Cance, said his organization is “strongly in favor of cancer patients and cancer survivors getting vaccinated, particularly older adults.”

Q: Should my 97-year-old mom, in a nursing home with dementia, get the covid vaccine?

The federal government and all 50 states recommend covid vaccines for long-term care residents, most of whom have Alzheimer’s disease or other types of cognitive impairment. This is an effort to stem the tide of covid-related illness and death that has swept through nursing homes and assisted living facilities — 37% of all covid deaths as of mid-January.

The Alzheimer’s Association also strongly encourages immunization against covid-19, “both for people [with dementia] living in long-term care and those living in the community, said Beth Kallmyer, vice president of care and support.

Minimizing suffering is a key consideration, said Dr. Michael Rafii, associate professor of clinical neurology at the University of Southern California’s Keck School of Medicine.

“Even if a person has end-stage dementia, you want to do anything you can to reduce the risk of suffering. And this vaccine provides individuals with a good deal of protection from suffering severe covid,” he said. “My advice is that everyone should get vaccinated, regardless of what stage of dementia they’re in.”

Q: I’m 80 and I have Type 2 diabetes and an autoimmune disease. Should I get the vaccine?

There are two parts to this question. The first has to do with “comorbidities” — having more than one medical condition. Should older adults with comorbidities get covid vaccines?

Absolutely, because they’re at higher risk of becoming seriously ill from covid, said Dr. Abinash Virk, an infectious diseases specialist and co-chair of the Mayo Clinic’s covid-19 vaccine rollout.

“Pfizer’s and Moderna’s studies specifically looked at people who were older and had comorbidities, and they showed that vaccine response was similar to [that of] people who were younger,” she noted.

The second part has to do with autoimmune illnesses such as lupus or rheumatoid arthritis, which also put people at higher risk. The concern here is that a vaccine might trigger inflammatory responses that could exacerbate these conditions.

Philippa Marrack, chair of the department of immunology and genomic medicine at National Jewish Health in Denver, said there’s no scientifically rigorous data on how patients with autoimmune conditions respond to the Pfizer and Moderna vaccines.

So far, reasons for concern haven’t surfaced. “More than 100,000 people have gotten these vaccines now, including some who probably had autoimmune disease, and there’s been no systematic reporting of problems,” Marrack said. If patients with autoimmune disorders are really worried, they should talk with their physicians about delaying immunization until other covid vaccines with different formulations become available, she suggested.

Last week, the National Multiple Sclerosis Society recommended that most patients with multiple sclerosis — another serious autoimmune condition — get the Pfizer or Moderna covid vaccines.

“The vaccines are not likely to trigger an MS relapse or to worsen your chronic MS symptoms. The risk of getting COVID-19 far outweighs any risk of having an MS relapse from the vaccine,” it said in a statement.

Kaiser Health News is a nonprofit news service covering health issues. It is an editorially independent program of the Kaiser Family Foundation, which is not affiliated with Kaiser Permanente.

What to Expect When COVID Vaccines Roll Out

By Judith Graham, Kaiser Health News

Vaccines that protect against COVID-19 are on the way. What should older adults and people with chronic illness expect? Will there be enough doses for everyone who wants to be vaccinated?

The first vaccine candidates, from Pfizer and Moderna, could arrive before Christmas, according to Alex Azar, who heads the Department of Health and Human Services.

Both vaccines are notably effective in preventing illness due to the coronavirus, according to information released by the companies, although much of the data from clinical trials is still to come. Both have been tested in adults age 65 and older, who mounted a strong immune response.

Seniors in nursing homes and assisted living centers will be among the first Americans vaccinated, following recommendations last week by a federal advisory panel. Older adults living at home will need to wait a while longer.

Many uncertainties remain. Among them: What side effects can older adults anticipate and how often will these occur? Will the vaccines offer meaningful protection to seniors who are frail or have multiple chronic illnesses?

Here’s a look at what’s known, what’s not and what lies ahead.

Timetable for Vaccines

Pfizer’s vaccine will be evaluated by a 15-member Food and Drug Administration advisory panel on Thursday. Moderna’s vaccine is expected to go before the panel Dec. 17.

At least two days before each meeting, an analysis by FDA staff will be made public. This will be the first opportunity to see extensive data about the vaccines’ performance in large phase 3 clinical trials, including more details about their impact on older adults.

So far, summary results disclosed in news releases indicate that Pfizer’s vaccine, produced in partnership with BioNTech, has an overall efficacy rate of 95% and efficacy of 94% in people 65 and older. Moderna’s overall efficacy is 94%, with 87% efficacy in preventing moderate disease in older adults, according to Moncef Slaoui, chief science adviser to Operation Warp Speed, the government’s COVID-19 vaccine development program.

If the advisory panel gives a green light, the FDA will decide within days or weeks whether to authorize the Pfizer and Moderna vaccines for emergency use. Distribution of the vaccine has already begun, and health care providers are expected to begin administering it immediately after the FDA acts.

Who Gets Vaccinated First?

At a Dec. 1 meeting of the Advisory Commission on Immunization Practices (ACIP), which guides the Centers for Disease Control and Prevention on vaccines, experts recommended that people living in long-term care (primarily nursing homes and assisted living facilities) and health care workers be the first groups to get COVID-19 vaccines.

This recognizes the extraordinary burden of COVID-19 in long-term care facilities. Although their residents represent fewer than 1% of the U.S. population, they account for 40% of COVID deaths — more than 100,000 deaths to date.

The commission’s decision comes despite a lack of evidence that Pfizer’s and Moderna’s vaccines are effective and safe for frail, vulnerable seniors in long-term care. Vaccines were not tested in this population. Federal officials insist side effects will be carefully monitored.

Next in line likely would be essential workers who cannot work from home, such as police, firefighters, teachers and people employed in food processing and transportation, according to commission deliberations Nov. 23 that have not come to a formal vote.

Then would be adults with high-risk medical conditions such as diabetes, cancer, kidney disease, obesity, heart disease and autoimmune diseases and all adults age 65 and older.

Although states typically follow ACIP guidelines, some states may choose, for instance, to vaccinate high-risk older adults before some categories of essential workers.

Left off the list are family caregivers, who provide essential support to vulnerable older adults living in the community — an unpaid workforce of tens of millions of people. “If someone is providing day-to-day care, it makes sense they should have access to the vaccine, too, to keep everyone safe,” said Beth Kallmyer, vice president of care and support for the Alzheimer’s Association.

Priority Groups

The priority groups constitute nearly half of the U.S. population — 21 million health care workers, 3 million long-term care residents, 66 million essential workers, more than 100 million adults with high-risk conditions and 53 million adults age 65 and older.

With initial supplies of vaccines limited, setting priorities will be inevitable. Practically, this means that hospitals and physicians may try to identify older adults who are at the highest risk of becoming seriously ill from COVID-19 and offer them vaccines before other seniors.

A study of more than 500,000 Medicare beneficiaries age 65 and older provides new evidence that could influence these assessments. It found the conditions that most increase older adults’ chances of dying from COVID-19 are sickle cell disease, chronic kidney disease, leukemias and lymphomas, heart failure, diabetes, cerebral palsy, obesity, lung cancer and heart attacks, in that order.

“Out of all Medicare beneficiaries, we identified just under 2,500 who had no medical problems and died of COVID-19,” said Dr. Martin Makary, co-author of the study and a professor of health policy and management at Johns Hopkins Bloomberg School of Public Health in Baltimore. “We knew risk was skewed toward comorbidity [multiple underlying medical conditions], but we didn’t realize it skewed this much.”

Supplies Available

Both the Pfizer and Moderna vaccines require two doses, administered three to four weeks apart. The companies have said about 40 million doses of their vaccines should be available this year, enough to fully vaccinate about 20 million people.

After that, 50 million doses might become available in January, followed by 60 million doses in both February and March, according to Dr. Larry Corey, a virologist who heads the COVID-19 Prevention Trials Network.

That translates into enough vaccine for another 85 million people and should be sufficient to vaccinate older adults in addition to medical personnel on the front lines and many other at-risk individuals, Corey suggested at a recent panel on COVID-19 sponsored by the National Academy of Medicine and American Public Health Association.

He acknowledged these were estimates, based on information he has been given. Pfizer and Moderna have not yet specified how much vaccine will be delivered and when. Nor is it clear when other vaccines under investigation will become available — 13 are in phase 3 clinical trials — or what their monthly production capacity might be.

Distribution Issues

As Pfizer’s and Moderna’s vaccines are rolled out, a very vulnerable group may have difficulty getting them: 2 million seniors who are homebound and another 5.3 million with physical impairments who have problems getting around.

The reason: handling and cold storage requirements.

Pfizer’s vaccine needs to be stored at minus 70 degrees Celsius, calling for special equipment not available in small hospitals, clinics or doctors’ offices. Moderna’s vaccine needs long-term storage at minus 20 degrees Celsius.

Landmark Health provides in-home medical care to more than 120,000 frail, chronically ill homebound seniors in 15 states. “We don’t have the capabilities to store and distribute these vaccines to our population,” said Dr. Michael Le, the company’s co-founder and chief medical officer.

Instead, he said, Landmark is working to arrange transportation for its patients to centers where COVID-19 vaccines will be administered and educating them about the benefits of the vaccines. “Given the trust, the bond we have with our patients, we can play a big role as advocates,” Le said.

Addressing Mistrust

Advocates have a big job ahead of them. According to a recent poll from the University of Michigan, only 58% of older adults (ages 50 to 80) said they were very or somewhat likely to get a COVID-19 vaccine. A significant number of older adults, 46%, thought they’d get the vaccine eventually but wanted others to go first. Only 20% wanted to get it as soon as possible.

Most important in making decisions is knowing how well the vaccine works, according to 80% of the 1,556 older adults surveyed. Just over half (52%) said a recommendation from their doctor would be influential.

Dr. Sharon Inouye, a geriatrician at Hebrew Senior Life in Boston and a professor of medicine at Harvard Medical School, is among the physicians impatiently awaiting the publication of data from Pfizer’s and Moderna’s phase 3 clinical trials.

Among the things she wants to know: How many older adults with chronic health conditions participated? How many participants were 75 and older? Did side effects differ for older adults?

“What I worry about most is the side effects,” she said. “We may not be able to know about serious but rare side effects until millions of people take them.”

But that’s a gamble she’s willing to take. Not only will Inouye get a vaccine, she just told her 91-year-old mother, who lives in assisted living, to say “yes” when one is offered.

“My whole family lives in fear that something will happen to her every day,” Inouye said. “Even though there’s a lot we still don’t know about these vaccines, it’s compelling that we protect people from this overwhelming illness.”

Kaiser Health News (KHN) is a national health policy news service. It is an editorially independent program of the Henry J. Kaiser Family Foundation which is not affiliated with Kaiser Permanente.