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: https://www.nature.com/articles/s41467-018-07515-0

How do you balance productivity & psychological safety in a lab? by Dr. Bowdish and others.

Cell Systems asks group leaders how they foster mutually reinforcing research productivity and psychological safety in their teams. Dr. Bowdish and others reflect on this question here…

SARS-CoV-2 & Back-To-School (Part 2). Ventilation & cleaning concerns

SARS-CoV-2 and Back-to-School Part 2: Transmission through air and surfaces

In Part 2 of this series we discuss the relative risk of infection through circulating air and on surfaces and some easy examples of how to break up air circulation patterns in schools.
Major points include:
1) Risks from circulating air versus surfaces
2) How masks, outside time (especially during meal time and when shouting/singing/playing music) and opening windows and doors can help reduce risk.
3) What to clean and when.
4) Beware of the break room! Occupational transmission often comes from colleagues – reduce the risk.

To download the slides, click here.

Dr. Bowdish talks with the CBC about whether we should worry about the coronovirus.

Canada is repatriating citizens from Wuhan, China. Should we be worried that this will bring the coronovirus to Canada?
Dr. Bowdish talks to CBC about the risks of bringing Canadians home, what we can do to protect ourselves from infection, and reveals that there is a virus circulating in Canada right now with similar symptoms that has killed hundreds of Canadians and is expected to kill hundreds more (it’s influenza and you should get your flu shot).

https://www.cbc.ca/listen/live-radio/1-82-here-and-now-toronto/clip/15758125-canada-is-going-to-try-and-repatriate-citizens-stuck-in-wuhan.-what-happens-next

Bowdish lab research on the evolution of MARCO featured in the New York Times

Our research on the scavenger receptor MARCO was featured in an article “Air Pollution, Evolution, and the Fate of Billions of Humans” by Carl Zimmer in the New York Times. In this manuscript we collaborated with Dr. Brian Golding, an expert in evolutionary biology in order to understand the evolution of this macrophage receptor. MARCO (or macrophage receptor with collagenous structure) is expressed on macrophages where it binds bacteria and particles such as those found in dust and air pollution. We had hypothesized that because it is the receptor for two pathogens, Streptococcus pneumoniae and Mycobacterium tuberculosis, that have played a major part in driving human evolution, that we might find evidence of areas of the receptor that were undergoing rapid evolution to protect us from this pathogen.

In order to determine which regions of the protein were changing we performed a phylogenetic analysis of the sequence of MARCO from humans, our close ancestors, the Denisovians and Neanderthals, and primates. We found a few interesting things. There was one mutation, which we call F282S (282 refers to the 282nd amino acid in the protein, the F = phenylalanine and the S= serine), had changed very rapidly. All our primate, Denisovian and Neanderthal relatives had a serine residue in that position but fully 83% of the human genomes we analyzed had a phenylalanine. The fact that this mutation spread so quickly through the population means that there must have been very strong selection pressure. We cloned both variants and found that the human specific variant was indeed better at binding inert particles and bacteria. There were a few other interesting mutations we characterized (see article below) but the take home message is that some of the evolutionary adaptations we have made to deal with pathogens may have influenced our ability to handle air pollution or, since the savannah was predicted to be a dry and dusty place, the adaptations we’ve made to deal with particulates in the air may have changed our response to pathogens.

To read the full article, see below.

Human-specific mutations and positively-selected sites in MARCO confer functional changes. Novakowski KE, Yap NVL, Yin C, Sakamoto K, Heit B, Golding GB, Bowdish DME. Mol Biol Evol. 2017 Nov 20. doi: 10.1093/molbev/msx298.
PMID: 2916561

Why does the public mistrust science? Radio interview with CHML.

Dr Bowdish talks to Scott Thompson on  CHML radio about a recent survey suggesting that more Canadians have lost their trust in science. Are scientists elitist? What can scientists do to regain the public’s trust ? Listen to this clip to hear more….

November is Lung Month – what do older adults need to know about pneumonia?

Dr Bowdish is the Canadian Lung Association’s spokesperson for World Pneumonia Day (November 12, 2018). Here she discusses the importance of being vaccinated for pneumonia….

She also speaks to Zoomer Magazine about pneumonia, vaccinations and the aging immune system here…

To get a sense of the other lung research going on in the Bowdish lab, see our Instagram page: house.macrophage

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