Quote of the Day
The most constructive lesson now lies in prevention by design. Adenoviral vectors still have scientific value in vaccines and gene delivery research. The goal is therefore sharper than simple abandonment. Researchers now have a defined protein target to modify or remove. If pVII or its critical epitope starts the harmful immune sequence, future developers can test safer vectors that preserve immunogenicity while avoiding this trigger. That possibility changes the tone of the discussion around COVID vaccine side effects. Scientists no longer need to speak only in broad associations or unresolved suspicion. They can work from a mapped antigen, a defined mutation, and a clearer susceptibility model. WHO said in 2021 that open, transparent, and evidence-based communication is essential to maintain trust. That principle still applies.
Surveillance systems detected rare blood clots from COVID vaccine campaigns. The scientific response then kept going until the biology became clearer. The new NEJM study does not answer every remaining question. It does, however, give medicine a credible molecular explanation and a practical route toward safer adenoviral vaccine design. That is the most useful takeaway from this long debate. The problem was rare, the mechanism was obscure, and the investigation kept moving until the evidence sharpened. For readers trying to understand blood clots from COVID vaccine programs without falling into panic or denial, that is the central point. Medicine now has a much better explanation for what happened, why it happened rarely, and how future vaccine engineering may reduce the risk even further. That progress also gave researchers a clearer path toward safer vectors, better screening, and more confident public communication about risk.
Bruce Abrahamse
March 25, 2026
This is why some people had blood clots from the COVID-19 vaccine and others didn’t
Please note that this is not one of the COVID-19 mRNA vaccines that so many people had concerns about.
Also note that the frequency of the blood clots was about 4 people per one million doses with the Johnson & Johnson vaccine. With the AstraZeneca vaccine it was about 2 cases per 100,000 in those aged 60 or older and 2 to 3 cases per 100,000 under 60.
These rates are so low that it is difficult to detect in testing. But when many hundreds of millions of people received the vaccine, the correlation became noticeable.
All vaccines (really all medical interventions) operate on a cost/benefit basis. There is always some level of negative side effects. So do the vaccines prevent more damage than they cause with side effects. Early smallpox vaccination (variolation) had a mortality rate of .5-2% but the mortality rate of the disease was 20-30%. You would have to multiply the latter number by the probability of getting the disease to get the true cost benefit. Disfigurement had a cost too as did the economic disruption caused by outbreaks but that is harder to quantify. Louis XVI and Marie Antoinette got vaccinated and had their children vaccinated as well which made it fashionable for the French nobility. George Washington, after the Continental Army was put out of action, ordered mandatory vaccination.
Where the COVID vaccines failed was on the benefit side. Remember the progression from no infection/no transmission to infection but no transmission to less severe infection but transmission to it works about as well as the flu vaccine. I am not sure we have seen the end of this progression. Given the weakness on the benefit side, the cost side becomes harder and harder to support.
For myself, by the time the vaccine was available the epidemic had run about a year and I was pretty sure I had natural immunity either from good genes or some previous infection. Nevertheless, I did the first two shots based on my history of never having a reaction and the promise that vaccinated people would be released from other restrictions. The first one proved true but the second was a lie. The first booster was just a repeat of the original one against a variant that was already extinct. The second booster was designed to protect against the new mutation. By that time it was clear that COVID was following the normal track of viral infections to become more contagious but less severe. So I punted the boosters. Never did get any variant of COVID unless it was so mild I didn’t notice.