Covaxin, Covishield or Both – A Mixed Approach

 Covaxin, Covishield or Both – A Mixed Approach

Mixing of vaccine doses is taking place in many countries of the world. Canada has also given its permission on 1 June and Bahrain on 4 June. In the UK, it started in January itself. Now America is also starting the trial. In India, it has been said in the Ministry of Health guidelines that the vaccine whose first dose has been taken, the second dose will also have to be taken. If another dose of the same vaccine is not available, then you will have to wait.

However, amidst the news coming from abroad, now Indian officials are also considering the mixing of vaccine doses. There has been confusion over the vaccine dosage in Gujarat and Uttar Pradesh; That is, those who had received the first dose of Covishield were given the second dose of Covaxin, and those who had received Covaxin were given the second dose of Covishield. No serious side effects or accidents have been reported in the states. At the same time, in view of the lack of supply, the gap of both the doses of Covishield has been changed thrice. Currently, only Sputnik V is being seen along with Covaxin and Covishield. If the vaccine increases from July-August, then there will be a fear of increasing the error. In case of supply interruption, there may be a long wait for the second dose.

Is mix-and-match of COVID-19 vaccine a good idea?

Covid-19 has become a cause of trouble all over the world. The shortage in supply of vaccines and the effectiveness of available vaccines has forced many countries to seriously consider mix-and-match. In many countries like India, due to the lack of timely supply of vaccine doses, people must wait a long time for the second dose.

Not only this, the risk of a new wave of Covid-19 and new variants is also increasing. It also weakens the effectiveness of the vaccine. Along with this, many countries have allowed or have prepared for the third booster dose.

Is the mix-and-match vaccine safe?

Yes, so far it has proved to be safe. In many countries of the world, there has been or is being studied on the mix-and-match of vaccine. Researchers at Oxford University conducted trials by mixing doses of Pfizer's mRNA vaccine with the AstraZeneca (we have Covishield) vaccine. It's safe. But its side effects have also been seen.

Matthew Snipe, associate professor of pediatrics and vaccinology at Oxford University, says the good thing is that this test has not revealed any new safety concerns. The immune response has also improved.

The Com-CoV study started in the UK in February. In this, the use of vaccines of AstraZeneca, Pfizer, Moderna, and Novavax was investigated. According to the Sunday Telegraph, promising results have been found in trials conducted on 600 people in Spain and 300 in Germany.

In a research, 26 youths in the age group of 25-46 years were given the first dose of AstraZeneca and the second dose of Pfizer. The results showed that the combination produced four times more neutralizing antibodies against the alpha variant found in the UK.

Has the vaccine been mixed before?

Yes, this is a practice that has been going on for decades. It was tried on viruses like Ebola. However, most combinations were of vaccines made from the same technology. A combination of rotavirus vaccines has been used in India. Mix-and-match trials of two rotavirus vaccines are going on for the last three years. This practice cannot be called new.

Why is a mix-and-match strategy necessary for India?

The government expects that seven to eight Covid-19 vaccines will be available in India in the next few months. These include vaccines made on viral vectors, mRNA, DNA, and recombinant protein platforms. Then it will be a big challenge to keep two doses of the same vaccine. Especially, in rural areas, much of the population is still illiterate. It will not be easy for them to remember the names of the vaccines.

India will get a chance to try many such combinations, which is not there in any other country in the world. Some vaccines are very inexpensive and can be made on a large scale. If these combinations are successful, they can prove to be very effective for poor and middle-income countries. They will also help in increasing the supply.

The initial vaccines are made against the original virus of Corona. Because of this, their effectiveness on the new variants is not known. Mixing vaccines made on different platforms will give new strength in the fight against the variants.

So far, doses of AstraZeneca have been tested with the Pfizer/Moderna vaccine in trials in Spain and the UK. We have not had Covaxin trials here. Similarly, mix-and-match trials of vaccines from Sputnik V and AstraZeneca is underway. India will also be ready for mixing and testing in the coming months.

So far, these countries have allowed mix-and-match:-

USA: Announced on June 1 that fully vaccinated adults will be given booster shots of the vaccine mixture. The results of the study will come by September.

Canada: Decided on 1 June that those who have received the first dose of AstraZeneca vaccine can take Pfizer or Moderna vaccine as a second dose.

UK: Decided in January that if someone does not know which vaccine was the first dose or the second dose is not available, then the available vaccine can be administered. In February, Pfizer and AstraZeneca announced the results of trials of mixing doses of the vaccine. Mixing of doses has given better results. The vaccines of Pfizer and Moderna has also been allowed to be used interchangeably.

Bahrain: On June 4, people vaccinated with Sinopharm Vaccine allowed Pfizer's booster shots. The UAE has also implemented a similar system.

Finland: On April 14, people under 65 were allowed a second dose of another vaccine after the first dose of AstraZeneca.

France: In April, people under 55 were allowed a second dose of either Pfizer or Moderna vaccine after the first dose of AstraZeneca.

Norway: After the first dose of AstraZeneca on 23 April, Pfizer or Moderna allowed a second dose of the vaccine.

South Korea: Said on 20 May that it would conduct trials on mixing a dose of AstraZeneca with Pfizer or any other vaccine.

Spain: On May 19, Pfizer allowed a second dose of Pfizer after the first dose of AstraZeneca for those under 60. The decision was taken after a preliminary study at the Carlos III Health Institute.

Sweden: On April 20, the first dose of AstraZeneca allowed anyone under 65 to receive a second dose of another vaccine.

China: In April, CanSino Biologics and Chongqing Jifei Biological Products began trials of a vaccine mixture.

Russia: On June 4, said that Arab countries had talked about starting trials of mixing the Sputnik V vaccine with the Chinese vaccine.

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