Measles is not a harmless childhood infection – Dr. Bowdish explains.

See Dr. Bowdish’s op-ed piece in the Globe & Mail.

The G&M article is paywalled so you can also read the text below with some additional links to relevant publications:

Dr. Dawn Bowdish is the executive director of the Firestone Institute for Respiratory Health, the Canada Research Chair in Aging and Immunity, and a professor of medicine at McMaster University.

Measles infections are on the rise, particularly in Europe and the U.S., while vaccination rates have declined – but too many have dismissed these trends, seeing measles as just a harmless childhood infection. But it is, in fact, the cause of the most deaths of all the vaccine-preventable infections. Canadian deaths from measles may be rare due to excellent medical care, but measles can have long-term consequences that are worth avoiding.

Before antibiotics were available, measles killed more people than influenza. When a child develops the high fever and rash characteristic of measles, the virus infects and destroys white blood cells, specifically those called lymphocytes. This leads to a period of immune-system suppression, where bacteria that normally live on and inside us without serious issue can cause deadly pneumonia or other infections.

With antibiotics, we can help children through this risky period, although the rise of antibiotic-resistant bacteria means that we can’t be as confident as we once were. What we can’t fix, however, is the damage that measles does to lymphocytes.

Our lymphocytes are essential to the generation of immune responses to new infections and vaccinations, but also in the system’s ability to “remember” the immune responses we’ve already generated. Measles infects and kills these critical immune cells. As a result, we know that a child who contracts measles will probably have more infections and more antibiotic prescriptions for at least five years after their infection, likely because they are getting sick with things that they once had immune protection from. We also know that even as their lymphocyte numbers recover, some are lost and the quality of others are reduced. This is why deaths from many unrelated infections also decreased when the measles vaccines were rolled out; measles no longer caused those children to “forget” their learned immune response.

Measles during pregnancy is dangerous. Miscarriage, premature labour, congenital birth defects, neurodevelopment disorders, or even the death of both mother and baby are all very real possibilities. In some parts of the world, when a woman plans to get pregnant and there is any doubt about her vaccine status, her healthcare provider will test for antibodies to make sure she is protected or recommend vaccination. In Canada, however, this is rare. Pregnant women are often not against being vaccinated, but often feel that not getting vaccinated is safer than getting vaccinated. This, compounded by a well-organized and concerted misinformation campaign about the measles vaccine that began in the 1990s, means that many people born in this era are now entering their child-bearing years having never received their childhood vaccines.

Measles is the most infectious virus we know of, and the increasing number of measles infections locally and globally mean that we can expect to see its tragic effects in pregnancy once again. Midwives, family doctors, and caregivers need to recommend vaccination for measles and other vaccine-preventable infections in the strongest possible terms.

There are some “known unknowns” that make the recent measles outbreaks particularly worrisome. We don’t know whether measles-induced immune suppression will make COVID, respiratory syncytial virus (RSV), streptococcal infections and other surging issues worse. We don’t know what proportion of Canadians have waning measles immunity and whether this means we need booster campaigns. We don’t know if people on immunosuppressant drugs or chemotherapy have lost their protective measles immunity, and if they have, we don’t know if our long-term care homes and cancer centres are at risk of outbreaks – though we do know that our strained healthcare and public health systems are under-resourced and will struggle to cope.

Misinformation, pandemic-related gaps in vaccine delivery, and the continuing countrywide shortages of family doctors means that many Canadians have not been vaccinated. But it’s not too late. The National Advisory Council on Immunization has clear guidance on how people of any age can catch up on their vaccines. If you have any doubt as to whether you were vaccinated, especially if you are thinking about becoming pregnant, speak to your health care provider or public health unit. Even if it turns out you were vaccinated and didn’t know it, there is no safety concern around getting vaccinated again. Children can also be vaccinated if they’ve missed their vaccines for any reason. And we should continue to enforce existing rules that require vaccines to go to school and work in certain sectors.

The terrible consequences of measles in pregnancy and childhood were known to our grandparents and great-grandparents. They are not a lesson that any of us need to learn again.

See also:

Dr. Bowdish discusses the lab’s research on microbiota and healthy/unhealthy aging on the Agora Health Podcast

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The Bowdish lab is no longer taking thesis or project students for the 2024/25 academic year, but click here for an opportunity for students interested in aging research.

Unfortunately the Bowdish lab is at capacity for undergraduate students for next year; however, if you are looking to meet supervisors doing research in aging MIRA (McMaster Institute for Research on Aging) is partnering with McMaster’s Association for Undergraduate Research on Aging (AURA) to host Meet Your Supervisor – an in-person, networking and informational session aimed at connecting undergraduate students seeking research experience with MIRA Researchers. MIRA will also share information about the MIRA Undergraduate Summer Research Fellowships.

RSVP to attend.

Event details:

WHEN: Monday January 22nd ,  4 – 5:30 PM

WHERE: Farncombe Atrium, HSC 3N4

Please RSVP by January 15, 2022

Publication: “Immunomodulatory drugs have divergent effects on humoral and cellular immune responses to SARS-CoV-2 vaccination in people living with rheumatoid arthritis”

Jenna Benoit (PhD candidate) has published her first, first author paper characterizing how immune responses to vaccination differ in people living with rheumatoid arthritis. We found some interesting new drug-immune interactions.

See the full paper here.

See thread here:

or below….

New paper alert! and team studied COVID-19 vaccinations in people living with rheumatoid arthritis who are on immunosuppressive drugs and found some interesting, and to our knowledge, unknown effects of specific drugs 1/n

Almost all studies of vaccine immunogenicity (i.e., how strong an immune response is to a vaccine) focus on antibody responses. Measuring the amount of antibodies produced is cheap and (relatively) easy; however, in the Omicron-era these are less predictive of protection than you might think 2/n

When investigating anti-receptor binding domain (RBD) antibodies and team found that -unsurprisingly- people living with RA and men had lower antibody responses (men have lower antibody responses to vaccination in general), and people with COVID had higher responses (i.e., that hybrid immunity you’ve heard so much about) 3/n

What caused these lower antibody responses? DMARDs (disease modifying anti-rheumatic drugs),and anti-TNF were not associated with lower antibody levels, the effect of steroids was not significant, but costimulation inhibitors reduced antibody levels 4/n

Important caveat: The effect of co-stimulation inhibitors was about the same as being a biologic male, so whether this reduction is associated with increased risk of infection or not is not something we can comment on 5/n.

We didn’t see an effect of drugs on neutralizing antibodies (i.e., antibodies that bind the virus really well and prevent it from entering us), but we did not have enough people on some of the drugs to really investigate this 6/n.

My favourite part: CD4+ and CD8+ T cell responses to vaccination are much, much harder to measure (each dot on the graph costs about $350 and 3+ hrs of time – hence the ‘team’ I keep mentioning) but we know that they are important for preventing infection.7/n

We found that people living with RA had lower CD4+ T cell responses (= ‘helper’ cells that support many aspects of the immune response to infection & vaccination), those who had had COVID were higher – more of that hybrid immunity you’ve heard about. 8/n

BUT even though we had a small number of people on JAK inhibitors, those who were on them had markedly lower CD4+ responses. The effect of co-stimulation inhibitors was not as apparent – but again low numbers of participants so hard to say. 9/n

Speculative side note: We use influenza vaccine as a control. Everyone has had exposure as kids so this measures a memory response made prior to having been vaccinated. Co-stim inhibitors don’t affect influenza but JAK inhibitors do – therefore no defect in pre-drug immune responses? 10/n

CD8+ T cell responses (‘killers’ of virus infected cells), were higher in men (previously known), and didn’t seem to be lower in most drugs, except maybe steroids. 11/n

Caveats: Our study was small and due to the fact we were measuring 1,2,3 doses, we were recruiting fast and furious and didn’t capture as many people on some of the drugs as we would have liked,so all results need to be replicated. 12/n

Clinical relevance: Some of these drugs are associated with increased risk of severe disease (see text for references) and by learning which aspects of the immune response they affect, we learn which aspects of the immune response are required for a successful vaccine. 13/n

Deepest appreciation for our research participants, the Canadian Arthritis Patient Alliance (see website for talks on this topic), the SUCCEED investigator team, our technical staff, fundign from the Public Health Agency of Canada, and you for reading to 14/n

Dr. Jessica Breznik talks about her research in the American Journal of Physiology-Gastrointestinal and Liver Physiology Podcast

In this podcast first author Dr. Jessica A. Breznik of McMaster University, discusses the recently published manuscript titled “Diet-induced obesity alters intestinal monocyte-derived and tissue-resident macrophages and increases intestinal permeability in female mice independent of tumor necrosis factor.” 

NEW & NOTEWORTHY We found that diet-induced obesity in female mice has tissue- and time-dependent effects on intestinal paracellular permeability as well as monocyte-derived and tissue-resident macrophage numbers, surface marker phenotype, and intracellular production of the cytokines IL-10 and TNF. These changes were not mediated by TNF.

Article Citation: Diet-induced obesity alters intestinal monocyte-derived and tissue-resident macrophages and increases intestinal permeability in female mice independent of tumor necrosis factorJessica A. Breznik, Jennifer Jury, Elena F. Verdú, Deborah M. Sloboda, and Dawn M. E. Bowdish

American Journal of Physiology-Gastrointestinal and Liver Physiology 2023 324:4, G305-G321

Dr. Bowdish speaks about COVID-19 vaccinations to the Canadian Arthritis Patient Alliance

On November 4, 2023, the Canadian Arthritis Patient Alliance hosted an educational webinar and panel discussion about COVID-19 vaccines moderated by Dr. Dawn Richards, Vice-President with CAPA. The panel included: – Nadine Lalonde, who lives with Systemic Lupus Erythematosus and is – involved as an active patient partner on various research projects and a member of the Arthritis Patient Advisory Board with Arthritis Research Canada – Inés Colmegna is a rheumatologist, researcher and Associate Professor of Medicine at McGill University – Dawn Bowdish is a Canada Research Chair in Aging and Immunity, and Professor, McMaster University #CAPA #CanadianArthritisPatientAlliance #arthritis #rheumatoidarthritis #arthritisawareness #livingwitharthritis #ra #ramedications #managingra #earlystagesofarthritis #arthritisadvocate #arthritispatient #arthritistreatment #rheumatoid #arthritisresource #didyouknow #flares #managingflares #flaring #vaccines #covid19 #RAvaccines