Posted on by Lawrence Tabak, D.D.S., Ph.D.
As colder temperatures settle in and people spend more time gathered indoors, cases of COVID-19 and other respiratory illnesses almost certainly will rise. That’s why, along with scheduling your annual flu shot, it’s now recommended that those age 5 and up should get an updated COVID-19 booster shot [1,2]. Not only will these new boosters guard against the original strain of the coronavirus that started the pandemic, they will heighten your immunity to the Omicron variant and several of the subvariants that continue to circulate in the U.S. with devastating effects.
At last count, about 14.8 million people in the U.S.—including me—have rolled up their sleeves to receive an updated booster shot . It’s a good start, but it also means that most Americans aren’t fully up to date on their COVID-19 vaccines. If you or your loved ones are among them, a new study may provide some needed encouragement to make an appointment at a nearby pharmacy or clinic to get boosted .
A team of NIH-supported researchers found a remarkably low incidence of severe COVID-19 illness last fall, winter, and spring among more than 1.6 million veterans who’d been vaccinated and boosted. Severe illness was also quite low in individuals without immune-compromising conditions.
These latest findings, published in the journal JAMA, come from a research group led by Dan Kelly, University of California, San Francisco. He and his team conducted their study drawing on existing health data from the Veterans Health Administration (VA) within a time window of July 2021 and May 2022.
They identified 1.6 million people who’d had a primary-care visit within the last two years and were fully vaccinated for COVID-19, which included receiving a booster shot. Almost three-quarters of those identified were 65 and older. Nearly all were male, and more than 70 percent had another pre-existing health condition that put them at greater risk of becoming seriously ill from a COVID-19 infection.
Over a 24-week follow-up period for each fully vaccinated individual, 125 per 10,000 people had a breakthrough infection. That’s about 1 percent. Just 8.9 in 10,000 fully vaccinated people—less than 0.1 percent—died or were hospitalized from COVID-19 pneumonia. Drilling down deeper into the data:
• Individuals with an immune-compromising condition had a very low rate of hospitalization or death. In this group, 39.6 per 10,000 people had a serious breakthrough infection. That translates to 0.3 percent.
• For people with other preexisting health conditions, including diabetes and heart disease, hospitalization or death totaled 0.07 percent, or 6.7 per 10,000 people.
• For otherwise healthy adults aged 65 and older, the incidence of hospitalization or death was 1.9 per 10,000 people, or 0.02 percent.
• For boosted participants 65 or younger with no high-risk conditions, hospitalization or death came to less than 1 per 10,000 people. That comes to less than 0.01 percent.
It’s worth noting that these results reflect a period when the Delta and Omicron variants were circulating, and available boosters still were based solely on the original variant. Heading into this winter, the hope is that the updated “bivalent” boosters from Pfizer and Moderna will offer even broader protection as this terrible virus continues to evolve.
The Centers for Disease Control and Prevention continues to recommend that everyone stay up to date with their COVID-19 vaccines. That means all adults and kids 5 and older are encouraged to get boosted if it has been at least two months since their last COVID-19 vaccine dose. For older people and those with other health conditions, it’s even more important given their elevated risk for severe illness.
What if you’ve had a COVID-19 infection recently? Getting vaccinated or boosted a few months after you’ve had a COVID-19 infection will offer you even better protection in the future.
So, if you are among the millions of Americans who’ve been vaccinated for COVID-19 but are now due for a booster, don’t delay. Get yourself boosted to protect your own health and the health of your loved ones as the holidays approach.
 CDC recommends the first updated COVID-19 booster. Centers for Disease Control and Prevention. September 1, 2022.
 CDC expands updated COVID-19 vaccines to include children ages 5 through 11. Centers for Disease Control and Prevention, October 12, 2022.
 COVID-19 vaccinations in the United States. Centers for Disease Control and Prevention.
 Incidence of severe COVID-19 illness following vaccination and booster with BNT162b2, mRNA-1273, and Ad26.COV2.S vaccines. Kelly JD, Leonard S, Hoggatt KJ, Boscardin WJ, Lum EN, Moss-Vazquez TA, Andino R, Wong JK, Byers A, Bravata DM, Tien PC, Keyhani S. JAMA. 2022 Oct 11;328(14):1427-1437.
COVID-19 Research (NIH)
Dan Kelly (University of California, San Francisco)
NIH Support: National Institute of Allergy and Infectious Diseases
Posted on by Dr. Francis Collins
Many people, including me, have experienced a sense of gratitude and relief after receiving the new COVID-19 mRNA vaccines. But all of us are also wondering how long the vaccines will remain protective against SARS-CoV-2, the coronavirus responsible for COVID-19.
Earlier this year, clinical trials of the Moderna and Pfizer-BioNTech vaccines indicated that both immunizations appeared to protect for at least six months. Now, a study in the journal Nature provides some hopeful news that these mRNA vaccines may be protective even longer .
In the new study, researchers monitored key immune cells in the lymph nodes of a group of people who received both doses of the Pfizer-BioNTech mRNA vaccine. The work consistently found hallmarks of a strong, persistent immune response against SARS-CoV-2 that could be protective for years to come.
Though more research is needed, the findings add evidence that people who received mRNA COVID-19 vaccines may not need an additional “booster” shot for quite some time, unless SARS-CoV-2 evolves into new forms, or variants, that can evade this vaccine-induced immunity. That’s why it remains so critical that more Americans get vaccinated not only to protect themselves and their loved ones, but to help stop the virus’s spread in their communities and thereby reduce its ability to mutate.
The new study was conducted by an NIH-supported research team led by Jackson Turner, Jane O’Halloran, Rachel Presti, and Ali Ellebedy at Washington University School of Medicine, St. Louis. That work builds upon the group’s previous findings that people who survived COVID-19 had immune cells residing in their bone marrow for at least eight months after the infection that could recognize SARS-CoV-2 . The researchers wanted to see if similar, persistent immunity existed in people who hadn’t come down with COVID-19 but who were immunized with an mRNA vaccine.
To find out, Ellebedy and team recruited 14 healthy adults who were scheduled to receive both doses of the Pfizer-BioNTech vaccine. Three weeks after their first dose of vaccine, the volunteers underwent a lymph node biopsy, primarily from nodes in the armpit. Similar biopsies were repeated at four, five, seven, and 15 weeks after the first vaccine dose.
The lymph nodes are where the human immune system establishes so-called germinal centers, which function as “training camps” that teach immature immune cells to recognize new disease threats and attack them with acquired efficiency. In this case, the “threat” is the spike protein of SARS-COV-2 encoded by the vaccine.
By the 15-week mark, all of the participants sampled continued to have active germinal centers in their lymph nodes. These centers produced an army of cells trained to remember the spike protein, along with other types of cells, including antibody-producing plasmablasts, that were locked and loaded to neutralize this key protein. In fact, Ellebedy noted that even after the study ended at 15 weeks, he and his team continued to find no signs of germinal center activity slowing down in the lymph nodes of the vaccinated volunteers.
Ellebedy said the immune response observed in his team’s study appears so robust and persistent that he thinks that it could last for years. The researcher based his assessment on the fact that germinal center reactions that persist for several months or longer usually indicate an extremely vigorous immune response that culminates in the production of large numbers of long-lasting immune cells, called memory B cells. Some memory B cells can survive for years or even decades, which gives them the capacity to respond multiple times to the same infectious agent.
This study raises some really important issues for which we still don’t have complete answers: What is the most reliable correlate of immunity from COVID-19 vaccines? Are circulating spike protein antibodies (the easiest to measure) the best indicator? Do we need to know what’s happening in the lymph nodes? What about the T cells that are responsible for cell-mediated immunity?
If you follow the news, you may have seen a bit of a dust-up in the last week on this topic. Pfizer announced the need for a booster shot has become more apparent, based on serum antibodies. Meanwhile, the Food and Drug Administration and Centers for Disease Control and Prevention said such a conclusion would be premature, since vaccine protection looks really good right now, including for the delta variant that has all of us concerned.
We’ve still got a lot more to learn about the immunity generated by the mRNA vaccines. But this study—one of the first in humans to provide direct evidence of germinal center activity after mRNA vaccination—is a good place to continue the discussion.
 SARS-CoV-2 mRNA vaccines induce persistent human germinal centre responses. Turner JS, O’Halloran JA, Kalaidina E, Kim W, Schmitz AJ, Zhou JQ, Lei T, Thapa M, Chen RE, Case JB, Amanat F, Rauseo AM, Haile A, Xie X, Klebert MK, Suessen T, Middleton WD, Shi PY, Krammer F, Teefey SA, Diamond MS, Presti RM, Ellebedy AH. Nature. 2021 Jun 28. [Online ahead of print]
 SARS-CoV-2 infection induces long-lived bone marrow plasma cells in humans. Turner JS, Kim W, Kalaidina E, Goss CW, Rauseo AM, Schmitz AJ, Hansen L, Haile A, Klebert MK, Pusic I, O’Halloran JA, Presti RM, Ellebedy AH. Nature. 2021 May 24. [Online ahead of print]
COVID-19 Research (NIH)
Ellebedy Lab (Washington University, St. Louis)
NIH Support: National Institute of Allergy and Infectious Diseases; National Center for Advancing Translational Sciences