Mixing Covid vaccines is not only safe and effective, but could also confer an even stronger immunity than having the same vaccine twice, according to a German study published a few days ago.
Research, which included 340 healthcare workers, suggests that the immune response was almost four times stronger than two doses of the same vaccine – the theory is that different types of vaccines (here AstraZeneca and Pfizer vaccinations) trigger different immune responses.
It wasn’t the first such finding – previous studies, including another in Germany and one in Spain with 670 people, have shown that a combination of AstraZeneca (AZ) and Pfizer elicits a strong immune response.
The idea of mixing vaccine types is not new. When developing a vaccine against Ebola, it was found that a mixed dose worked best and activated both the T cells and B cells of the immune system [File photo]
All you have to do is note the obvious hiccups in the April AZ jab delivery to see why health officials might want to be able to mix up jabs – to keep the rollout programs going.
In fact, Professor Jeremy Brown, a member of the JCVI’s Joint Committee on Vaccination and Immunization, has already said that vaccine mixing will be inevitable.
“It has to be practically like that,” he said two weeks ago. “Once you’ve completed a two-dose course with, for example, Moderna or Pfizer or AstraZeneca, it will be quite difficult in the future to make sure you get the same vaccine again.”
But for people like me, it’s a real and immediate concern – life or death, arguably. That’s because I’m at risk of stroke – I’m not unhealthy (I don’t smoke, drink moderately, and have been vegetarian since I was 12), but I had bad Covid-19 in March last year.
Not so terrible that I called 999, but serious enough that my GP described it as “difficult”. In addition to the complications of viral pneumonia and bacterial pneumonia, I developed extreme tiredness, chest pain, liver inflammation, shortness of breath and hair loss (approx. 60 percent) over the months.
Then in December I suddenly felt dizzy. It was only 7:30 p.m., but the only thing I could think about was going to bed. Since my right leg wasn’t doing it, I somehow crawled up the stairs and slept for ten hours.
The next morning I called an ambulance with my right side and especially my hand, weak and weak, and was taken to the hospital. Research confirmed that I had had a stroke caused by a blood clot in the right side of my brain.
Mixing Covid vaccines is not only safe and effective, but could also confer an even stronger immunity than having the same vaccine twice, according to a German study published a few days ago
Strokes are a known side effect of Covid that makes the blood “sticky” and more prone to clot. When I got home three days later, I had a large bag of pills, including two blood thinners, three drugs to lower blood pressure, and a statin.
It was all a bit of a shock to someone who was otherwise so healthy.
I struggled with terrible side effects on my right side. I could neither write nor type – an abysmal handicap for a writer. I dropped things and crashed because my grip was poor, I would sometimes fall over if I leaned too far.
Classified as extremely clinically at risk, I was queued for the Covid-19 vaccination and received the AstraZeneca vaccine at the end of January.
But before I could have the second, word came in March that some people had developed rare blood clots (in the brain and occasionally in the stomach) after the first AstraZeneca vaccination.
Then in April the news came that the death rate among those who developed the clots was high – 19 percent of those affected. And in May, the AZ jab was linked to stroke.
If you’re devastated by a stroke, you’ll do everything possible to avoid another – before my second AZ vaccination was due in late April, I contacted my GP to see if I could get Pfizer instead.
I was told I had been referred to a local hospital where the Pfizer vaccination was being offered. But the hospital said no, blaming the national guidelines issued by the JCVI.
In fact, according to the guidelines, mixing is allowed in certain circumstances, such as when someone had to be hospitalized after a bad reaction to the first one.
On April 23, just a day later, a friend of mine got Pfizer after getting AstraZeneca in February.
“It wasn’t until I looked at the map in the recovery room that I realized,” he told me. He assumes that they only had Pfizer to offer that day.
The idea of mixing vaccine types is not new. When developing a vaccine against Ebola, it was found that a mixed dose worked best and activated both the T cells and B cells of the immune system.
T cells destroy infected cells and B cells sweep up leftover virus and make antibodies.
A Chinese study in March found that combinations of four Covid-19 vaccines improved immune responses in mice.
Then, in mid-May, the Spanish study of 670 volunteers found that those who had AZ and then Pfizer had an antibody response 30 to 40 times stronger than the double AZ group.
And now there’s talk of “mixing up” jabs with the over-55 boosters that will inevitably appear next fall.
But what about those like me who are still waiting for their second push and don’t want the AZ? The question has become more pressing as we learned last month that the chances of getting the rare brain clot after an initial dose of AZ increased from 1 in 250,000 to 1 in 81,300.
This week: eggs
“For optimal freshness and food safety, eggs should be kept at a constant temperature below 20 ° C and we recommend keeping them in their original boxes in the refrigerator,” says Andrew Joret, Chairman of the British Egg Industry Council.
“In the extremely unlikely event that Salmonella [a bacterium] is present in an egg, storage below 20 ° C would minimize the risk of this reproduction. ‘
The box can help prevent other smells (e.g. onion) from getting into the eggs – so it is recommended to keep them in the container.
The new delta variant is considered transferable. A study led by Public Health England found that we need two vaccinations to protect ourselves adequately.
After the first dose we are 33 percent protected against it; this increases to 88 percent two weeks after the second Pfizer dose and to 66 percent after the second AZ.
I contacted the vaccination center again, but received confirmation on May 25th that they will not distance themselves from their policies.
A harrowing revelation came just a day later: the AZ vaccine has been linked to ischemic strokes (caused by blood clots) that I have had. Three people in the UK who had blood clots after the AZ vaccination had been hospitalized and one, a 35-year-old woman, had died.
The report from the National Hospital for Neurology and Neurosurgery in London puts the likelihood of a blood clot at one in 100,000 doses.
But if you’ve already had a stroke that doubles your chance of another within five years, surely you must have an above-average risk of stroke after the AZ vaccination? I know friends and their relatives who have previously had blood clots who refused to get a second AZ. Should they stay unvaccinated?
Professor Anthony Harnden, vice chairman of the JCVI, suggests that they should have the same vaccine “since there is no published data on the mix of vaccination schedules”.
Two weeks ago my GP told me that he can now refer me for a Pfizer or Moderna vaccination – although the JCVI guidelines haven’t changed.
Yesterday, a stroke doctor confirmed that I should avoid AZ because one stroke significantly increases the risk of a second stroke. I can’t wait to be called!