Although it is very easy to get the COVID-19 vaccine in most parts of the United States now, the promotion of the vaccine in other parts of the world is slow or inconsistent due to the following reasons Shortage, uneven visits with Concerns about safety.
Researchers hope that the mix-and-match approach of COVID-19 vaccines will help alleviate these problems and create greater flexibility in the immunization regimens available to people.
Around the world, different pharmaceutical companies have adopted different methods to develop vaccines.Created by Pfizer BioNTech and Moderna mRNA vaccine. Oxford-AstraZeneca and Johnson & Johnson chose the so-called Viral vectorThe Novavax COVID-19 vaccine is Protein-based.
Therefore, mixed vaccines may mean more than just changing manufacturers—for example, from Pfizer’s first dose to Moderna’s second dose.You might be entering a Different ways to stimulate the immune response If you choose the first dose of AstraZeneca and the second dose of Moderna.
The most obvious benefit of treating various brands and types of COVID-19 vaccines as interchangeable is logistics – People can get any available lens without any worries. By accelerating the launch of global vaccination, Mix and match vaccines can help end this pandemicThe researchers also hope that combining different vaccines will trigger Stronger and longer lasting immune response Compared with receiving two doses of a single vaccine.This method may Better protect people From emerging variants.
Biological effects of mix and match methods
Scientists suspect there are several ways to get two different COVID-19 vaccines May cause a stronger immune response.
Slightly used by companies Different regions of SARS-CoV-2 spike protein In their recipe. Your immune system responds to the spike protein of the virus, so contact with different parts of the spike protein means your body will produce a series of corresponding antibodies to fight off future infections. Then, the antibody range should provide better protection and increase the possibility of protecting you from changes in the spike protein.
Different vaccine technologies activate unique aspects of the immune system, thanks to how they present their spike protein portion.
This Pfizer with Modern The vaccine consists of a small piece of mRNA, and the genetic material contains a formula for the production of the SARS-CoV-2 spike protein region. The mRNA encapsulated in the fat layer slides into the cells of the vaccinated person, where it directs the production of viral proteins. The human immune system then recognizes the foreign spike protein and produces antibodies against it.
Several other COVID-19 vaccines rely on Viral vector. In these cases, researchers Modified an adenovirus that usually causes the common cold Send the DNA instructions to produce a portion of the SARS-CoV-2 spike protein. The modified virus is safe because it cannot replicate in the human body.along with Johnson with AstraZeneca, Examples of COVID-19 virus vector vaccines used worldwide include Sputnik 5 with CanSino Biologics vaccine.
Your immune system can develop Immune response to the viral vector vaccine itself, Which may reduce the effectiveness of the vaccine against coronavirus.Experts hope to combine vaccine platforms, such as using mRNA-based vaccines or vaccines containing different viral vectors For the second dose, Can reduce this risk.
Investigate the safety and effectiveness of the combination
Research is ongoing around the world In animals and people To figure it out When a person is vaccinated with two different COVID-19 vaccines, the safety, the type of immune response and the duration of immunity.
Results of the Spanish trial More than 600 people said that simultaneous vaccination with the viral vector AstraZeneca and the mRNA-based Pfizer-BioNTech COVID-19 vaccine can trigger a strong immune response against the SARS-CoV-2 virus.
Preliminary results learn to German Research that has not been peer-reviewed has found that compared with two doses of AstraZeneca vaccine, first vaccination with AstraZeneca vaccine and then with Pfizer vaccine will produce more protective antibodies and provide better protection against mutations of concern .
Com-COV research In the UK, the safety and effectiveness of the combined use of AstraZeneca and Pfizer BioNTech injections for patients are also being investigated. Preliminary findings It showed that people who received each type of vaccine were more likely to report mild to moderate side effects than those who received two doses of the same vaccine. The final results of this study, including the effectiveness of this method, are expected to be announced in June 2021. Extended Com-CoV2 research Other combinations of the COVID-19 vaccine are being tested, namely the mRNA platform from Moderna and the protein platform from Novavax.
Combination may be a good anti-mutation strategy
The newly emerging variant of the coronavirus is one of them The most interesting reason Consider mixed vaccines. Managing vaccines against different variants will provide broad collective immunity and limit the emergence of new strains that may be more dangerous.
People who are currently fully vaccinated may need a third shot to resolve the genetic difference of the new mutation. Changing this booster injection platform—for example, if your first round is based on viral vectors, switch to mRNA or protein-based—can help boost your immune response.
Flu vaccine usually prevents Multiple strains of influenza virus – But these are usually made by the same company. In the future, this method may produce vaccines containing multiple regions of SARS-CoV-2 to prevent several variants, or regions containing both coronavirus and influenza proteins, thereby preventing both viruses at once.
Content allowed so far
However, for now, the U.S. Centers for Disease Control and Prevention only allows the mixing of mRNA-based Pfizer and Moderna injections in the “Special case“For example, the limited supply of vaccines, or if patients don’t know which vaccine they were given initially.
The Public Health Agency of Canada recently approved Mixing different COVID-19 vaccines If a limited supply prevents someone from getting a second dose of the same vaccine, or If anyone is worried about the second dose of AstraZeneca Due to public side effects.
EU countries so far Waiting for further research results Before allowing the vaccine dose to be mixed.