A study done by the Carlos III Health Institute in Spain, has concluded that the under-60s who have already received one shot of the Oxford-AstraZeneca vaccine can be safely administered the Pfizer-BioNTech medication for their second dose.
The study named CombivacS had a total of 772 volunteers and 472 of them received the Pfizer as their second shot, and 221 were used as a control group who didn't receive the second jab.
The study proved that second dose using the Pfizer vaccine is “highly immunogenic and safe.” The vaccinated group saw its immune response multiply by 120 a week after this second dose, while the control group’s level held steady. When the serum of the patients was mixed in the laboratory with samples of the coronavirus the neutralizing defense response was shown to multiply by seven. In the equivalent trials with a second dose of AstraZeneca, this response was multiplied by three.
Basically by combining these two vaccines, the neutralizing antibody response shot up by 7 times.
PS: I always argued for mixing of the vaccines because the combination could offer an higher efficacy than using the booster shot of the same vaccine. This is what the Russians were doing from the very beginning. Gameleya uses TWO vaccines, the primer uses rAd26 and the booster uses rAd5 - two different adeno-viruses as the transport mechanism (vectors). Though they didn't admit or say - This it was really a mix and match.
This is possible because all current vaccines target the S-protein. Except the Chinese ones and Bharat Bio-Tech. These are inactivated, and hence cannot say much unless tested. Also there's one more inactivated vaccine due from Europe.
The UK trial on mix & match, and the Gameleya trial results (AZ with their Sputnik Booster) have not been published yet.
Pls refer to my older post on another thread...
https://elakiri.com/threads/කොවිෂීල්ඩ්-වැක්සීන්-ඵක-ගහපු-අයට-චයිනීස්-ඵක-ගහන්න-යන්නේ.1985932/page-2
<snip>
Even though CDC says the above, mainly because it's untested, the vaccine designers believe that you can mix. Because all the current vaccines (except the inactivated ones, like the Chinese and Bharat BioTech) target the spike protein.
Both AZ and Gamelaya are quite similar vector vaccines, AZ uses a Chimp virus and Gamelaya two human adenoviruses (rAd5 & rAd26)... I have given the full details earlier.
Now think carefully - what the Russians are doing? They really are mixing TWO different vaccines but deliver the same payload - which is the Spike Protein - and their one works better than all others. When I say the Spike protein, it's either a partial or a complete copy of the protein depending on the vaccine.
Both AZ and Gamelaya use the same method (viral vector) and only the vectors are different and in theory should work well together.
Most scientists have the view that because all vaccines deliver the same payload, but using different mechanisms, there should be no problems.
However a trial is currently being done (started a while ago) in the UK and they have enrolled more than a 1000 people who had already received one jab but not the other. These people will be randomly allocated to receive either the same vaccine for their second dose or a dose of another.
Also Gamelaya themselves were coordinating with Oxford to trial out the AZ with their second jab. Many believe this is the best mix & match and hence my original comment.
Once the results are out I will update. Note that both Germany and France already mixing the vaccines due to the blood clotting issue. There is no problem with using the same vaccine for both shots but when it's not practical to do so, other avenues have to be worked out.
I did mention the T-cell response earlier on another post. It's not only the antibodies at work here.... there are other factors at play. Too long to describe in short.
<snip>
The study named CombivacS had a total of 772 volunteers and 472 of them received the Pfizer as their second shot, and 221 were used as a control group who didn't receive the second jab.
The study proved that second dose using the Pfizer vaccine is “highly immunogenic and safe.” The vaccinated group saw its immune response multiply by 120 a week after this second dose, while the control group’s level held steady. When the serum of the patients was mixed in the laboratory with samples of the coronavirus the neutralizing defense response was shown to multiply by seven. In the equivalent trials with a second dose of AstraZeneca, this response was multiplied by three.
Basically by combining these two vaccines, the neutralizing antibody response shot up by 7 times.
PS: I always argued for mixing of the vaccines because the combination could offer an higher efficacy than using the booster shot of the same vaccine. This is what the Russians were doing from the very beginning. Gameleya uses TWO vaccines, the primer uses rAd26 and the booster uses rAd5 - two different adeno-viruses as the transport mechanism (vectors). Though they didn't admit or say - This it was really a mix and match.
This is possible because all current vaccines target the S-protein. Except the Chinese ones and Bharat Bio-Tech. These are inactivated, and hence cannot say much unless tested. Also there's one more inactivated vaccine due from Europe.
The UK trial on mix & match, and the Gameleya trial results (AZ with their Sputnik Booster) have not been published yet.
Pls refer to my older post on another thread...
https://elakiri.com/threads/කොවිෂීල්ඩ්-වැක්සීන්-ඵක-ගහපු-අයට-චයිනීස්-ඵක-ගහන්න-යන්නේ.1985932/page-2
<snip>
Even though CDC says the above, mainly because it's untested, the vaccine designers believe that you can mix. Because all the current vaccines (except the inactivated ones, like the Chinese and Bharat BioTech) target the spike protein.
Both AZ and Gamelaya are quite similar vector vaccines, AZ uses a Chimp virus and Gamelaya two human adenoviruses (rAd5 & rAd26)... I have given the full details earlier.
Now think carefully - what the Russians are doing? They really are mixing TWO different vaccines but deliver the same payload - which is the Spike Protein - and their one works better than all others. When I say the Spike protein, it's either a partial or a complete copy of the protein depending on the vaccine.
Both AZ and Gamelaya use the same method (viral vector) and only the vectors are different and in theory should work well together.
Most scientists have the view that because all vaccines deliver the same payload, but using different mechanisms, there should be no problems.
However a trial is currently being done (started a while ago) in the UK and they have enrolled more than a 1000 people who had already received one jab but not the other. These people will be randomly allocated to receive either the same vaccine for their second dose or a dose of another.
Also Gamelaya themselves were coordinating with Oxford to trial out the AZ with their second jab. Many believe this is the best mix & match and hence my original comment.
Once the results are out I will update. Note that both Germany and France already mixing the vaccines due to the blood clotting issue. There is no problem with using the same vaccine for both shots but when it's not practical to do so, other avenues have to be worked out.
I did mention the T-cell response earlier on another post. It's not only the antibodies at work here.... there are other factors at play. Too long to describe in short.
<snip>
