COVID-19
COVID-Related Excess Death and Sickness
🫀 This paper from Sweden (2025-11-18) reports that getting COVID-19 increases your risk of cardiovascular diseases. Compared to people who did not catch COVID-19, people who did get COVID-19 infections had:
- +22% higher risk of acute myocardial infarction;
- (many other things with in-between risks);
- 331% higher risk of a pulmonary embolism.
People who were hospitalized for COVID-19 had a 10.77 times risk of all-cause mortality compared to never-COVIDers (AKA “NOVIDs”; people who had mild cases had a 50% higher risk of all-cause mortality as NOVIDs.
Pathology
💊 This slightly older paper from Canada (2025-06-08) reports that participants who used antibiotics in the three months before COVID-19 infection had more serious infections than participants who did not. People exposed to antibiotics were:
- 48% more likely to have an emergency department visit;
- 37% more likely to be hospitalized;
- 27% more likely to die.
The association between antibiotics and bad outcomes was stronger in people who had more exposure, had exposure to more broad-spectrum antibiotics, or were younger.
The paper says that antibiotic use reduces gut bacterial levels, and cites two studies (this and this) which found that antibiotic use decreased the (useful) response to vaccinations.
🧠This paper from Sweden (2025-11-14) reports that people who had mental illnesses were more likely to get Long COVID. Specifically, people with Long COVID were more likely to have had a mental illness diagnosis before catching COVID-19 than matched controls without Long COVID did:
| previous illness | extra risk for women | extra risk for men |
| depression | +57% | +40% |
| anxiety | +65% | +110% |
| ME/CFS | +96% | +122% |
| headache | +145% | +189% |
I want to remind people of this interview from Netherlands (2025-11-03), which I recommended two weeks ago. It talks about how mental illness and the immune system are more tightly connected than you would have thought. (Quoting Ed Jong again: Immunology is where intuition goes to die.)
Mitigation Measures
😲 This paper using Chinese data (2025-07-21) reports that students’ math scores actually went up by 8 to 11% in China during online learning. They speculated that greater parental supervision and reduced distractions improved childrens’ performances. They did say that online learning was better for reasoning-based subjects (e.g. math, science), but not as good for interpretation-heavy subjects (e.g. English, history).
Transmission
🤰😬 This paper from China (2025-11-21) reports that fetuses can get infected with SARS-CoV-2 from their mothers.
Vaccines
🤔💉 This paper (2025-11-25) reports that tattooed mice had a reduced response to a COVID-19 mRNA vaccination. However, tattooed mice had an improved response to an inactivated influenza virus vaccine.
Influenza
Vaccines
💉 This paper from UK (2025-11-19) reported on the results of an influenza vaccine challenge trial — meaning that they vaccinated some healthy young human volunteers, deliberately inoculated them and some unvaccinated healthy young controls with the flu (an A/H1N1), and then saw what happened.
- A new mRNA flu vaccine from Pfizer was 100% effective — ONE HUNDRED PERCENT EFFECTIVE — against laboratory-confirmed flu (and also against flu-with-fever).
- Somewhat to my surprise, the quadrivalent influenza vax that’s in use now was 84.5% against infection and 100% against flu-with-fever.
This editorial (2025-11-19) points out that the trial population was young healthy adults, and that the VE in the general population for the quadrivalent vaccine is more like 40% to 50%… so the mRNA flu vaccine probably will not be 100% effective in the general population.
The flip side, however, is that if you are a young and healthy adult, the flu shot is probably better than the VE you might have seen!
RSV
Vaccines Immunizations
💉 Data keeps coming in about how awesome nirsevimab is against RSV for infants:
- This paper from Italy (2025-11-20) reports that nirsevimab was 68% effective against hospitalization when figured one way and 89% effective when figured a different way.
- This paper from USA (2025-11-20) reports that in hospitalized infants, nirsevimab is 80% effective against ICU admission and 83% effective against acute respiratory failure.
💉 They were hoping that the RSV vaccine for older adults would be sterilizing, i.e. one-and-done, but, alas, no. This paper from USA (2025-11-24) reports that RSV vaccines in older adults wane:
| against | VE in first month | VE at 18 months |
| infection | 82.5% | 59.4% |
| emergency visits | 84.9% | 60.5% |
| hospitalization | 88.9% | 57.3% |
| ICU | 92.5% | 71.9% |
I bet this means that pub health will start to recommend that older adults get an RSV booster every year or every other year.
💉 The NACI guidance on RSV shots (2025-03-13) strongly recommends RSV vaccinations for people over 75 or over 60 in “chronic care facilities”. (No, I don’t know if prisons count as “chronic care facilities”.)
NACI also says that “an RSV vaccine may be considered as an individual decision by adults 50 to 74 years of age in consultation with their health care provider”. I suspect that’s code for “you can get it, but you’re going to have to pay for it yourself.”
💰 This oldish article (2023-12-10) said that Ontario was the only province that going to pay for an RSV shot, but that was before the NACI guidance came out. I also don’t know if Ontario will pay for a booster (as opposed to the first shot).
The 2023 article also said that the vax was going to cost $200-350. (I have it on extremely good authority that it cost $176.49 in Vancouver in November 2023.)
EBV
Vaccines
Two weeks ago, I talked about how Epstein-Barr Virus was implicated in a huge number of diseases, and that I wished for a vaccine. (And I didn’t even remember the different cancers associated with EBV: nasopharyngeal carcinoma, gastric carcinoma, Hodgkin lymphoma, Burkitt lymphoma, diffuse large B-cell lymphoma and xxtranodal NK/T-cell lymphoma/nasal type.)
💉 I decided to go look into EBV vaccines, and discovered that this article (2025-08-25) says that four companies are doing early clinical trials 🎉:
- Moderna (phase 1 started 2022 and 2023, phase 2 started 2025),
- US National Institute of Allergy and Infectious Diseases (NIAID) (one phase 1 started 2022, another for a slightly different vax is recruiting),
- Modex/Mereck phase 1 started 2025), and
- EBViously is a German company that said they wanted to start trials in 2024, and the 2025-08-25 article above says they started, but I see no evidence that they actually did.
I also see evidence of a few Chinese studies of EBV vaccines specifically for cancer patients.
Measles
Transmission
According to the Government of Canada Measles and Rubella Monitoring Report (updated 2025-11-24), in the week ending 15 November, the following jurisdictions had the following number of cases:
- Canada: 14 (<- this is down significantly from last week!);
- Manitoba: 7;
- BC: 6;
- Alberta: 1.